VARDENAFIL

Uncategorized 1 Response »

Jan 312014

VARDENAFIL

224785-90-4^{CAS NO}

Vardenafil hydrochloride (CAS NO.224785-91-5)

Formula	C₂₃H₃₂N₆O₄S
Mol. mass	488.604 g/mol

4-[2-Ethoxy-5-(4-ethylpiperazin-1-yl)sulfonyl-phenyl]-9-methyl-7-propyl-3,5,6,8-tetrazabicyclo[4.3.0]nona-3,7,9-trien-2-one

Vivanza, Vardenafil (INN), Levitra (TN), STK642629, , LEVITRA

Vardenafil (INN) is a PDE5 inhibitor used for treating erectile dysfunction that is sold under the trade names Levitra (Bayer AG, GSK, and SP) andStaxyn.

Vardenafil was co-marketed by Bayer Pharmaceuticals, GlaxoSmithKline, and Schering-Plough under the trade name Levitra. As of 2005, the co-promotion rights of GSK on Levitra have been returned to Bayer in many markets outside the U.S. In Italy, Bayer sells vardenafil as Levitra and GSK sells it as Vivanza. Thus, because of European Union trade rules, parallel imports might result in Vivanza sold next to Levitra in the EU.

Vardenafil (Levitra) is an oral therapy for the treatment of erectile dysfunction. It is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Penile erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpus cavernosum and its associated arterioles. During sexual stimulation, nitric oxide is released from nerve endings and endothelial cells in the corpus cavernosum. Nitric oxide activates the enzyme guanylate cyclase resulting in increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection. The tissue concentration of cGMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs). The most abundant PDE in the human corpus cavernosum is the cGMPspecific phosphodiesterase type 5 (PDE5); therefore, the inhibition of PDE5 enhances erectile function by increasing the amount of cGMP.

An orally disintegrating form, marketed as Staxyn, has been gaining approvals in countries such as the United States^[1] and Canada.^[2]

Vardenafil’s indications and contra-indications are the same as with other PDE5 inhibitors; it is closely related in function to sildenafil citrate (Viagra) and tadalafil (Cialis). The difference between the vardenafil molecule and sildenafil citrate is a nitrogen atom’s position and the change of sildenafil’spiperazine ring methyl group to an ethyl group. Tadalafil is structurally different from both sildenafil and vardenafil. Vardenafil’s relatively short effective time is comparable to but somewhat longer than sildenafil’s.

Beyond its indications for erectile dysfunction, vardenafil may be effective in the treatment of premature ejaculation, where it may significantly increase the time from vaginal penetration to ejaculation.^[3]

The common, adverse drug reactions (side-effects) are the same as with other PDE5 inhibitors. The frequent vardenafil-specific side-effect is nausea; the infrequent side-effects are abdominal pain, back pain, photosensitivity, abnormal vision, eye pain, facial edema, hypotension, palpitation,tachycardia, arthralgia, myalgia, rash, itch, and priapism.

One possibly serious, but rare, side-effect with vardenafil is heart attack. Also, in rare cases, vardenafil use may cause priapism, a very painful emergency condition that can cause impotence if left untreated.^[4]

On 18 October 2007, the U.S. Food and Drug Administration (FDA) announced that a warning about possible deafness (sudden hearing loss) would be added to the drug labels of Vardenafil, and other PDE5 inhibitors.^[5]

Vardenafil, as with all PDE5 inhibitors, should not be used by men taking nitrate medications, because combining them with vardenafil might provoke potentially life-threatening hypotension (low blood pressure).

Further, Vardenafil causing lengthening of the QT interval. Therefore it should not be taken by men taking other medications that affect the QT interval (such as amiodarone).

Levitra 20mg Oral Tablet

It is available in 2.5 mg, 5 mg, 10 mg, and 20 mg doses in round orange tablets. The normal starting dose is 10 mg (roughly equivalent to 50 mg of sildenafil). Vardenafil should be taken 1 to 2 hours prior to sexual activity, with a maximum dose frequency of once per day. In some territories, such as the UK, only certain doses may be available.

Vardenafil is also available under the name Staxyn as a tablet which dissolves on the tongue rather than being swallowed in the form of a pill.

STAXYN is an oral therapy for the treatment of erectile dysfunction. This monohydrochloride salt of vardenafil is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific PDE5.

Vardenafil HCl is designated chemically as piperazine, 1-[[3-(1,4-dihydro-5-methyl-4-oxo-7-propylimidazo[5,1f][1,2,4]triazin-2-yl)-4-ethoxyphenyl]sulfonyl]-4-ethyl-, monohydrochloride and has the following structural formula:

STAXYN (vardenafil hydrochloride) Structural Formula Illustration

Vardenafil HCl is a nearly colorless, solid substance with a molecular weight of 579.1 g/mol and a solubility of 0.11 mg/mL in water.

LEVITRA

TRIHYDRATE, HCL SALT

Abbreviated New Drug Application (ANDA)

US2002137930A

vardenafil hydrochloride is piperazine, 1-[[3-(1,4-dihydro-5-methyl-4-oxo-7-propylimidazo[5,1-f][1,2,4]triazin-2-yl)-4-ethoxyphenyl]sulfonyl]-4-ethyl-, mono -hydrochloride and can be structurally represented by Formula I.

The monohydrochloride salt of vardenafil is a selective inhibitor of cyclic guaosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). It is commercially available in products sold under the brand name LEVITRA formulated as 2.5 mg, 5 mg, 10 mg, 20 mg film-coated tablets.

U.S. Pat. No. 6,362,178 B1 discloses vardenafil, its related compounds and processes for their preparation. The patent describes a process in which vardenafil is obtained by recrystallization in ether in Example 19. Vardenafil produced as per Example 19 is hereinafter referred as “crystalline Form I” of vardenafil. The patent also describes processes for the preparation of its monohydrochloride and dihydrochloride salts, which are formed in a combination of ether and dichloromethane. The patent also describes a process for the preparation of vardenafil monohydrochloride trihydrate.

U.S. Patent Application Publication No. 2005/0203298 also describes a process for the preparation of vardenafil, and its monohydrochloride trihydrate.

Chemical synthesis of vardenafil has mostly been directed to the preparation of the trihydrate of monohydrochloride of vardenafil.

In WO 99/24433, sulphonamide-substituted imidazotriazinones are described as potent inhibitors of either one or more of the cyclic guanosine 3′,5′-monophosphate-metabolizing phosphodiesterases (cGMP PDEs). According to the nomenclature of Beavo and Reifsnyder (Trends in Pharmacol. Sci. 11, 150-155, 1990), these cGMP PDEs are the phosphodiesterase isoenzymes PDE-I, PDE-II and PDE-V.

According to WO 99/24433, the sulphonamide-substituted imidazotriazinones described therein are prepared from corresponding 2-ethoxyphenyl-substituted imidazotriazinones by reaction with chlorosulphonic acid and subsequent reaction with an appropriate amine, as is illustrated by the following scheme (R¹to R⁶here have the meanings indicated in WO 99/24433):

In this process, highly reactive chlorosulphonic acid has to be used as a reagent. Moreover, the imidazotriazinonesulphonyl chlorides formed as intermediates are sensitive to hydrolysis, which, in particular in the conversion of this preparation process to the industrial scale, can lead to not inconsiderable yield variations.

It was therefore the object of the present invention to make available a process for the preparation of sulphonamide-substituted imidazotriazinones in which the disadvantages of the above process known from the prior art are avoided.

This object is achieved according to the present invention by a process as in claim 1. In particular, in the process according to the invention as in claim 1 the use of chlorosulphonic acid is avoided by introduction of the sulphonic acid via a reaction with sulphuric acid and subsequent reaction with thionyl chloride. Moreover, the reaction with thionyl chloride and the subsequent reaction with an amine is carried out in a one-pot process, so that the imidazotriazinonesulphonyl chloride intermediate, which is sensitive to hydrolysis, does not need to be isolated. By means of this, yield variations on account of partial hydrolysis of this intermediate can be excluded. As a result of these advantages, the process according to the invention is much simpler to carry out on the industrial scale than the process described in WO 99/24433.

………………….

SYNTHESIS

US6362178

2-butyrylamino-propionic acid

EXAMPLE 1A 2-Butyrylaminopropionic acid

22.27 g (250 mmol) of D,L-alanine and 55.66 g (550 mmol) of triethylamine are dissolved in 250 ml of dichloromethane, and the solution is cooled to 0° C. 59.75 g (550 mmol) of trimethylsilyl chloride are added dropwise, and the solution is stirred for 1 hour at room temperature and for 1 hour at 40° C. After cooling to −10° C., 26.64 g (250 mmol) of butyryl chloride are added dropwise, and the resulting mixture is stirred for 2 hours at −10° C. and for one hour at room temperature.

With ice-cooling, 125 ml of water are added dropwise and the reaction mixture is stirred at room temperature for 15 minutes. The aqueous phase is evaporated to dryness, the residue is titrated with acetone and the mother liquor is filtered off with suction. The solvent is removed and the residue is chromatographed. The resulting product is dissolved in 3N aqueous sodium hydroxide solution and the resulting solution is evaporated to dryness. The residue is taken up in conc. HCl and once more evaporated to dryness. The residue is stirred with acetone, precipitated solid is filtered off with suction and the solvent is removed under reduced pressure. This gives 28.2 g (71%) of a viscous oil which crystallizes after some time.

200 MHz ¹H-NMR (DMSO-d6): 0.84, t, 3H; 1.22, d, 3H; 1.50, hex, 2H; 2.07, t, 2H; 4.20, quin., 1H; 8.09, d, 1H.

EXAMPLE 3A 2-Ethoxybenzonitrile

25 g (210 mmol) of 2-hydroxybenzonitrile are refluxed with 87 g of potassium carbonate and 34.3 g (314.8 mmol) of ethyl bromide in 500 ml of acetone overnight. The solid is filtered off, the solvent is removed under reduced pressure and the residue is distilled under reduced pressure. This gives 30.0 g (97%) of a colourless liquid.

200 MHz ¹H-NMR (DMSO-d6): 1.48, t, 3H; 4.15, quart., 2H; 6.99, dt, 2H; 7.51, dt, 2H.

2-ethoxybenzamidine hydrochloride

EXAMPLE 4A 2-Ethoxybenzamidine hydrochloride

21.4 g (400 mmol) of ammonium chloride are suspended in 375 ml of toluene, and the suspension is cooled to 0° C. 200 ml of a 2M solution of trimethylaluminium in hexane are added dropwise, and the mixture is stirred at room temperature until the evolution of gas has ceased. After addition of 29.44 g (200 mmol) of 2-ethoxybenzonitrile, the reaction mixture is stirred at 80° C. (bath) overnight.

With ice-cooling, the cooled reaction mixture is added to a suspension of 100 g of silica gel and 950 ml of chloroform, and the mixture is stirred at room temperature for 30 minutes. The mixture is filtered off with suction, and the filter residue is washed with the same amount of methanol. The mother liquor is concentrated, the resulting residue is stirred with a mixture of dichloromethane and methanol (9:1), the solid is filtered off with suction and the mother liquor is concentrated. This gives 30.4 g (76%) of a colourless solid.

200 MHz ¹H-NMR (DMSO-d6): 1.36, t, 3H; 4.12, quart., 2H; 7.10, t, 1H; 7.21, d, 1H; 7.52, m, 2H; 9.30, s, broad, 4H.

EXAMPLE 10A 2-(2-Ethoxy-phenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

7.16 g (45 mmol) of 2-butyrylamino-propionic acid and 10.67 g of pyridine are dissolved in 45 ml of THF and, after addition of a spatula tip of DMAP, heated to reflux. 12.29 g (90 mmol) of ethyl oxalyl chloride are slowly added dropwise, and the reaction mixture is refluxed for 3 hours. The mixture is poured into ice-water and extracted three times with ethyl acetate and the organic phase is dried over sodium sulphate and concentrated using a rotary evaporator. The residue is taken up in 15 ml of ethanol and refluxed with 2.15 g of sodium bicarbonate for 2.5 hours. The cooled solution is filtered.

With ice-cooling, 2.25 g (45 mmol) of hydrazine hydrate are added dropwise to a solution of 9.03 g (45 mmol) of 2-ethoxybenzamidine hydrochloride in 45 ml of ethanol, and the resulting suspension is stirred at room temperature for another 10 minutes. The ethanolic solution described above is added to this reaction mixture, and the mixture is stirred at a bath temperature of 70° C. for 4 hours. After filtration, the mixture is concentrated, the residue is partitioned between dichloromethane and water, the organic phase is dried over sodium sulphate and the solvent is removed under reduced pressure.

This residue is dissolved in 60 ml of 1,2-dichloroethane and, after addition of 7.5 ml of phosphorus oxychloride, refluxed for 2 hours. The mixture is diluted with dichloromethane and neutralized by addition of sodium bicarbonate solution and solid sodium bicarbonate. The organic phase is dried and the solvent is removed under reduced pressure. Chromatography using ethyl acetate and crystallization afford 4.00 g (28%) of a colourless solid, R_f=0.42 (dichloromethane/methanol=95:5)

200 MHz ¹H-NMR (CDCl₃): 1.02, t, 3H; 1.56, t, 3H; 1.89, hex, 2H; 2.67, s, 3H; 3.00, t, 2H; 4.26, quart., 2H; 7.05, m, 2H; 7.50, dt, 1H; 8.17, dd, 1H; 10.00, s, 1H.

EXAMPLE 15A 4-Ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]triazin-2-yl)-benzenesulphonyl chloride

At 0° C., 2.00 g (6.4 mmol) of 2-(2-ethoxy-phenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one are slowly added to 3.83 ml of chlorosulphonic acid. At room temperature, the reaction mixture is stirred ovemight, and then poured into ice-water and extracted with dichloromethane. This gives 2.40 g (91%) of a colourless foam.

200 MHz ¹H-NMR (CDCl₃): 1.03, t, 3H; 1.61, t, 2H; 1.92, hex, 2H; 2.67, s, 3H; 3.10, t, 2H; 4.42, quart., 2H; 7.27, t, 1H; 8.20, dd, 1H; 8.67, d, 1H; 10.18, s, 1H.

Example 19 2-[2-Ethoxy-5-(4-ethyl-piperazine-1-sulphonyl)-phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

470 mg (1.14 mmol) of 4-ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]triazin-2-yl)-benzenesulphonyl chloride are dissolved in 20 ml of dichloromethane and cooled to 0° C. 390 mg (3.42 mmol) of N-ethylpiperazine are added, and the reaction mixture is stirred at room temperature overnight. The mixture is diluted with dichloromethane, the organic phase is washed twice with water and dried over sodium sulphate and the solvent is removed under reduced pressure. Crystallization from ether gives 370 mg (66%) of a colourless solid.

400 MHz ¹H-NMR (CDCl₃): 1.01, t, 3H; 1.59, t, 3H; 1.88, hex, 2H; 2.42, quart., 2H; 2.56, m, 4H; 2.63, s, 3H; 3.00, t, 2H; 3.10, m, 4H; 4.33, quart., 2H, 7.17, d, 1H; 7.88, dd, 1H; 8.44, d, 1H; 9.75, s, 1H.

…………………….

US7977478

EXAMPLE 7 Preparation of the Trihydrate of Vardenafil Monohydrochloride

14 g of vardenafil hydrochloride was taken into a round bottom flask followed by the addition of 70 ml water and the pH of the reaction mass was adjusted using sodium hydroxide to 11 at 30° C. 280 ml of dichloromethane was added to the above reaction mass and the layers were separated. The organic layer was dried over sodium sulfate and the organic layer was transferred into a round bottom flask and subjected to heating for distillation at 40° C. for 1.5 hours. The solid material was transferred into a round bottom flask and 36 ml of a mixture of acetone and water in 12:1 ratio was added with stirring, then 2.2 ml of 36% aqueous hydrochloric acid was added with stirring. The reaction mass was heated to a temperature of about 45° C. and the undissolved particles were removed by filtration. The filtrate was taken into a round bottom flask and cooled to 5° C., maintained for 45 minutes at 3 to 5° C. followed by the filtration of the solid which was then subjected to suction drying and finally dried at 40° C. to yield 9.0 g of the trihydrate of vardenafil monohydrochloride.

……………………..

US20050203298

STARTING COMPOUNDS

Example I Preparation of 2-(2-ethoxyphenyl)-5-methyl-7-propyl-3H-imidazo-[5,1-f][2,4]triazin-4-oneIa) Preparation of 2-butyrylaminopropionic acid

A solution of 100 kg of D,L-alanine in aqueous sodium hydroxide solution is reacted in the cold with 119 kg of butyryl chloride. After addition of butyl acetate, the mixture is acidified with hydrochloric acid, the organic phase is separated off and the aqueous phase is re-extracted. The organic phase is dried by azeotropic distillation. The crystallizate is isolated, washed with butyl acetate and dried.

Yield: 132.6 kg (68%)

¹H-NMR: δ=0.8 (t, 3H), 1.25 (d, 3H), 1.5 (m, 2H), 2.1 (t, 2H), 4.2 (q, 1H), 8.1 (d, NH), 12.0-12.7 (s, COOH)

MS: 336 (2M+NH₄, 40), 319 (2M+H, 15), 177 (M+NH₄, 100), 160 (M+H, 20)

Ib) Preparation of 2-ethoxybenzonitrile

260 kg of thionyl chloride are added at 85-95° C. to a suspension of 250 kg of 2-ethoxybenzamide in toluene under metering control. The reaction mixture is stirred in the presence of heat. Thionyl chloride and toluene are then distilled off in vacuo. The product is employed in the subsequent stage as a crude product.

Yield: 228.5 kg (crude product)

¹H-NMR: δ=1.45 (t, 3H), 4.15 (q, 2H), 7.0 (m, 2H, phenyl), 7.5 (m, 2H, phenyl)

MS: 312 (2M+N₄, 35), 165 (M+NH₄, 100), 147 (5)

Ic) Preparation of 2-ethoxy-N-hydroxybenzamidine

111 kg of 2-ethoxybenzonitrile (crude product) from Example Ib are heated under reflux with 164 1 of triethylamine and 73 kg of hydroxylamine hydrochloride in isopropanol. The reaction mixture is treated with water and cooled. The crystallizate is isolated, washed and employed in the subsequent stage as a moist product.

Yield: 92.6 kg (moist product)

¹H-NMR: δ=1.35 (t, 3H), 4.1 (q, 2H), 5.6 (s, 2H), 6.9-7.4 (4H, phenyl), 9.4 (s, 1H, OH)

MS: 361 (2M+H, 30), 198 (M+N, 30), 181 (M+H, 100)

Id) Preparation of 2-ethoxybenzamidine hydrochloride

135 kg of 2-ethoxy-N-hydroxybenzamidine (moist product) from Example Ic are hydrogenated at 50-60° C. in acetic acid using palladium on carbon as a catalyst. For the work-up, the hydrogenation reaction is freed from the catalyst, treated with hydrochloric acid and concentrated. Residual acetic acid and water are removed by azeotropic distillation with toluene. The crystallizate is isolated and dried in vacuo.

Yield: 136.4 kg

H-NMR: 1.35 (t, 3H), 4.15 (q, 2H), 7.1-7.7 (m, 4H, phenyl), 9.1-9.4 (2×s, 3H), 10.5-10.7 (s, 1H)

MS: 329 (2M+H, 10), 165 (M+H, 100)

Ie) Preparation of 2-(2-ethoxyphenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]-triazin-4-one

231 kg of 2-butyrylaminopropionic acid from Example Ia are treated in tetrahydrofuran with 341 kg of pyridine, catalytic amounts of 4-N,N-dimethylaminopyridine and 392 kg of ethyl chloroxalate and stirred with heating under reflux. The reaction mixture is taken up in ethyl acetate, washed with water and the ethyl acetate phase is concentrated. The distillation residue is taken up in methanol and reacted with the following solution.

192 kg of 2-ethoxybenzamidine hydrochloride from Example Id are treated in methanol with 47.5 kg of hydrazine hydrate and the mixture is stirred at room temperature. The solution is combined with the solution of 2-butyrylamino-1-ethoxycarbonylpropenyl ethyl oxalate prepared above. The reaction mixture thus obtained is stirred with heating under reflux. Methanol is removed by distillation and replaced by acetic acid.

Option A:

138.6 kg of phosphorus oxychloride are added and stirred in the presence of heat.

Acetic acid is distilled off in vacuo. The residue is treated with water and dichloromethane or optionally methyl isobutyl ketone and rendered neutral using sodium hydroxide solution. The organic phase is concentrated, and the residue is dissolved in acetone and crystallized with cooling. The crystallizate is isolated, washed and dried.

Option B:

At least 190 kg of acetyl chloride are added and stirred in the presence of heat. Acetic acid is distilled off in vacuo. The distillation residue is treated with acetone and water, and the product is crystallized by rendering neutral with sodium hydroxide solution. The product is isolated, washed and dried.

Yield: 90-160 kg

¹H-NMR: δ=1.0 (t, 3H), 1.6 (t, 3H), 1.9 (m, 2H), 2.8 (s, 3H), 3.3 (t, 2H), 4.3 (q, 2H), 7.0-8.2 (Ar, 4H), 10.3 (CONH, 1H)

MS: 313 (M+H, 100), 149 (25), 151 (40), 121 (15)

HPLC: Kromasil C-18 phase, neutral phosphate buffer, acetonitrile, 233 nm, linear gradient of 30% acetonitrile ->80% acetonitrile (30 min.): 99 area % (R_t19.1)

PREPARATION EXAMPLES Example 1a 4-ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydroimidazo[5,1-fl-][1,2,4]triazin-2-yl)benzenesulphonic acid

194 kg of 2-(2-ethoxyphenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one from Example Ie are reacted with 504 kg of concentrated sulphuric acid. The reaction mixture is added to water, cooled, and the crystallizate is isolated and dried in vacuo.

Yield: 195.2 kg

¹H-NMR: δ=0.95 (t, 3H), 1.3 (t, 3H), 1.8 (m, 2H), 2.6 (s, 3H), 3.05 (t, 2H), 4.1 (q, 2H), 7.15 (Ar, 1H), 7.75 (m, 2H), 12.3 (SO₂OH)

MS: 393 (M+H, 100), 365 (25), 151 (40)

HPLC: X-Terra C-18 phase, aqueous phosphoric acid, acetonitrile, 242 nm, linear gradient of 10% acetonitrile ->90% acetonitrile (20 min.):

98 area % (R, 9.2)

Example 1b) 2-[2-ethoxy-5-(4-ethlylpiperazin-1-sulphonyl)phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

22.5 kg of 4-ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]-triazin-2-yl)benzenesulphonic acid from Example 1a are reacted with 74 kg of thionyl chloride and catalytic amounts of dimethylformamide until the evolution of gas has ended. Xylene is repeatedly added to the reaction mixture and thionyl chloride is distilled off. 15.1 kg of N-ethylpiperazine are added to the suspension and it is stirred. After the addition of water, it is adjusted to pH 1 using hydrochloric acid, and the phases are separated. The aqueous phase is treated with acetone and rendered neutral by addition of sodium hydroxide solution. The mixture is cooled, and the crystallizate is isolated, washed and dried in vacuo.

Yield: 26.1 kg

¹H-NMR: δ=1.0 (2×t, 6H), 1.6 (t, 3H), 1.9 (m, 2H), 2.45 (q, 2H), 2.55 (m, 4H), 2.65 (s, 3H), 3.0 (t, 2H), 3.1 (m, 4H), 4.35 (q, 2H), 7.15 (Ar, 1H), 7.9 (Ar, 1H), 8.4 (Ar, 1H), 9.8 (CONH)

MS: 489 (M+H, 100), 345 (10), 313, (10), 285 (10), 113 (20)

HPLC: X-Terra C-18 phase, neutral phosphate buffer, acetonitrile, 242 nm, linear gradient of 20% acetonitrile ->75% acetonitrile (20 min.): 98 area % (R_t16.3)

1 c) 2-[2-ethoxy-5-(4-ethylpiperazin-1-sulphonyl)phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-fl][1,2,4]triazin-4-one hydrochloride trihydrate

22.5 kg of 2-[2-ethoxy-5-(4-ethylpiperazin-1-sulphonyl)phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one from Example 1b are dissolved in 5.1 kg of concentrated hydrochloric acid and acetone/water (12:1 v/v) in the presence of heat. The clear solution is filtered hot and crystallized by cooling and seeding. The crystallizate is isolated, washed and dried in vacuo at about 30° C. and about 300 mbar.

Yield: 25.4 kg

M.p. (DSC): 192° C.

HPLC: X-Terra C-18 phase, neutral phosphate buffer, acetonitrile, 242 nm, linear gradient of 20% acetonitrile ->75% acetonitrile (20 min.): 99 area % (R_t16.3)

http://www.pharmpro.com/News/Feeds/2010/06/pharmaceutical-companies-bayer-new-erectile-dysfunction-treatment-staxyn-approve/
http://www.newswire.ca/en/story/832217/staxyn-new-innovation-in-erectile-dysfunction-helps-younger-men-rise-to-the-occasion
A Aversa et al. “Effects of vardenafil administration on intravaginal ejaculatory latency time in men with lifelong premature ejaculation”. Retrieved 2010-12-14.
Schools of Pharmacy (Glen L. Stimmel, Pharm.D., and Mary A. Gutierrez, Pharm.D.) and Medicine (Glen L. Stimmel, Pharm.D.), University of Southern California, Los Angeles, California. “Counseling Patients About Sexual Issues: Drug-Induced Priapism”. Medscape. Retrieved 2010-12-06.
“FDA Announces Revisions to Labels for Cialis, Levitra and Viagra”. Food and Drug Administration. 2007-10-18. Retrieved 2009-08-06.

Official Levitra website
PubChem Information

23313637

2-1-2013

Synthesis of quinoline derivatives: discovery of a potent and selective phosphodiesterase 5 inhibitor for the treatment of Alzheimer’s disease.

European journal of medicinal chemistry

PATENTS

US6362178 *	Oct 31, 1998	Mar 26, 2002	Bayer Aktiengesellschaft	2-phenyl substituted imidazotriazinones as phosphodiesterase inhibitors
US20050203298 *	May 5, 2005	Sep 15, 2005	Bayer Healthcare Aktiengesellschaft	Process for the preparation of sulphonamide-substituted imidazotriazinones
US20060111354 *	Jul 3, 2003	May 25, 2006	Peter Serno	Medicaments containing vardenafil hydrochloride trihydrate
WO2004006894A1 *	Jul 3, 2003	Jan 22, 2004	Bayer Healthcare Ag	Medicaments containing vardenafil hydrochloride trihydrate

US2011269750	11-4-2011	ROFLUMILAST FOR THE TREATMENT OF DIABETES MELLITUS
US8017633	9-14-2011	Roflumilast for the Treatment of Diabetes Mellitus
US2011190495	8-5-2011	N-BUTYRAMIDE, THE PREPARATION METHOD AND USE THEREOF
US2011048980	3-4-2011	Fatty Acid Oxidation Inhibitors Treating Hyperglycemia and Related Disorders
US2011009367	1-14-2011	2-PHENYL SUBSTITUTED IMIDAZOTRIAZINONES AS PHOSPHODIESTERASE INHIBITORS
US2010234388	9-17-2010	SUBSTITUTED PDE5 INHIBITORS
US2010179131	7-16-2010	Combination treatment for diabetes mellitus
US7704999	4-28-2010	2-Phenyl substituted imidazotriazinones as phosphodiesterase inhibitors
US7696206	4-14-2010	2-PHENYL SUBSTITUTED IMIDAZOTRIAZINONES AS PHOSPHODIESTERASE INHIBITORS
US2010029671	2-5-2010	Heterocyclic Compounds And Uses Thereof In The Treatment Of Sexual Disorders


US2009318459	12-25-2009	Therapeutic Compositions Comprising a Specific Endothelin Receptor Antagonist and a PDE5 Inhibitor
US2009291958	11-27-2009	Substituted PDE5 inhibitors
US2009221570	9-4-2009	Uses of 2-Phenyl-Substituted Imidazotriazinone Derivatives for Treating Pulmonary Hypertension
US2009215836	8-28-2009	Roflumilast for the Treatment of Pulmonary Hypertension
US2009196900	8-7-2009	Use of Phosphodiesterase Inhibitor as a Component of Implantable Medical Devices
US2009163504	6-26-2009	Method for healing a wound using a phosphodiesterase type five inhibitor
US2009074796	3-20-2009	Pde5 inhibitor compositions and methods for immunotherapy
US2009062313	3-6-2009	Pde5 inhibitor compositions and methods for treating cardiac indications
US2008268046	10-31-2008	Formulations with Controlled Release of Active Ingredient
US2008194529	8-15-2008	HIGHLY SELECTIVE and LONG-ACTING PDE5 MODULATORS

US2008187588	8-8-2008	Formulations With Controlled Release Of Active Ingredient
US2008085897	4-11-2008	Use of 2-alkoxyphenyl-substituted imidazotriazinones
US7314871	1-2-2008	2-phenyl substituted imidazotriazinones as phosphodiesterase inhibitors, for treatment of hypertension
US2007299088	12-28-2007	Novel Uses of 2-Phenyl-Substituted Imidazotriazinone Derivatives
US7276504	10-3-2007	Use of 2-alkoxyphenyl-substituted imidazotriazinones
US2006264624	11-24-2006	Methods for synthesizing imidazotriazinones
US7122540	10-18-2006	2-Phenyl substituted imidazotriazinones as phosphodiesterase inhibitors
US6998483	2-15-2006	Process for the preparation of sulphonamide-substituted imidazotriazinones
US6930108	8-17-2005	Use of 2-alkoxyphenol-substituted imidazotriazinones
US6890922	5-11-2005	2-phenyl substituted imidazotriazinones as phosphodiesterase inhibitors

US2005014756	1-21-2005	Process for the preparation of sulphonamide-substituted imidazotriazinones
US6777551	8-18-2004	Process for the preparation of sulphonamide-substituted imidazotriazinones
US2004152700	8-6-2004	Novel use of 2-phenyl-substituted imidazotriazinones
US2003144296	7-32-2003	Daily treatment for erectile dysfunction using a PDE5 inhibitor
US6566360	5-21-2003	2-phenyl substituted imidatriazinones as phosphodiesterase inhibitors
US6362178	3-27-2002	2-phenyl substituted imidazotriazinones as phosphodiesterase inhibitors
US2001053780	12-21-2001	Daily treatment for erectile dysfunction using a PDE5 inhibitor
WO9924433	5-21-1999	2-PHENYL SUBSTITUTED IMIDAZOTRIAZINONES AS PHOSPHODIESTERASE INHIBITORS

////////////

Lodenafil Carbonate … an Erectile Dysfunction Drug in Phase III

Phase 3 drug, Uncategorized 1 Response »

Jan 312014

Lodenafil carbonate

UNII-29X84F932D, CRIS-031

bis-(2-{4-[4-ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-benzenesulfonyl]piperazin-1-yl}-ethyl)carbonate

5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one. IS THE NAME OF MONOMER

398507-55-6 CAS

Cristalia (Originator)

C47 H62 N12 O11 S2= MF
Molecular Weight	1035.199

Lodenafil is a drug belonging to a class of drugs called PDE5 inhibitor, which many other erectile dysfunction drugs such as sildenafil, tadalafil, and vardenafil also belong to. Like udenafil and avanafil it belongs to a new generation of PDE5 inhibitors.

Sildenafil, tadalafil, vardenafil, and the newer udenafil and avanafil selectively inhibit PDE5, which is cGMP-specific and responsible for the degradation of cGMP in the corpus cavernosum. These phosphodiesterase inhibitors are used primarily as remedies for erectile dysfunction, as well as having some other medical applications such as treatment of pulmonary hypertension.

Lodenafil is formulated as a dimer, lodenafil carbonate, which breaks down in the body to form two molecules of the active drug lodenafil. This formulation has higher oral bioavailability than the parent drug.^[1]

It is manufactured by Cristália Produtos Químicos e Farmacêuticos in Brazil and sold there under the brand-name Helleva.^[2]

Helleva (Lodenafil Carbonate) - 80mg (4 Tablets)

Helleva (Lodenafil Carbonate) is an oral PDE5 inhibitor prescribed to treat men suffering from erectile dysfunction. It operates by relaxing muscles and dilating blood vessels in the penis to increase circulation making it easier to attain and maintain an erection.

It has undergone Phase III clinical trials,^[3]^[4]^[5] but is not yet approved for use in the United States by the U.S. Food and Drug Administration.

lodenafil

………..

SYNTHESIS

WO 2002012241 OR US7148350

MONOMER synthesis

PIPERAZINE

AND

ETHYL CHLORO ACETATE

WILL GIVE

Ethyl 1-piperazinylacetate ChemSpider 2D Image | Ethyl 1-piperazinylacetate | C8H16N2O2

SEE RXN 1 BELOW

Reaction 1:

Synthesis of Piperazine Ethyl Acetate

To a reaction blend containing 100 g (3 Eq, 0.515 mol, MW=194) of piperazine, 26.3 mL (1.1 Eq, 0.189 mol, MW=101, d=0.726) of triethylamine in 200 mL of isopropanol, add to a solution previously prepared of 18.4 mL (1 Eq., 0.172 mol, MW=122.55, d=1.15) of chloroacetate of ethyl in 140 mL of isopropanol under stirring, at room temperature. Keep the reaction medium under stirring, monitoring the reaction termination by means of a chromatography of the thin layer (about 2–3 hours). Add a solution of 40.6 g (0.344 mol) of succinic acid in 140 mL of isopropanol. Keep the system under stirring for about 30 minutes to assure total precipitation of the succinate salt of piperazine formed. Filter this salt and concentrate the filtrate containing the mono and dialkyled derivatives. We obtain a slightly yellowish oil, which is used in later phases without purification.

Mass obtained=33 g

GC/MS: Monoalkylated derivative 72%, and dialkylated 22%.

ChemSpider 2D Image | Ethyl 1-piperazinylacetate | C8H16N2O2 Piperazine Ethyl Acetate

AND

5-(5-Chlorosulfonyl-2-ethoxyphenyl)-1-methyl-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one Structure

5-(5-chlorosulfonyl-2-ethoxyphenyl)-1-methyl-3n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one

WILL REACT TO GIVE… 5-{2-ethoxy-5-[(4-ethyl acetate 1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-di-hydro-7H-pyrazole[4,3-d]pyrimidin-7-one AS IN RXN 4 BELOW

Reaction 4:

Synthesis of 5-{2-ethoxy-5-[(4-ethyl acetate 1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-di-hydro-7H-pyrazole[4,3-d]pyrimidin-7-one.

Suspend 24.6 g (60 mmol, MW=410.9) of 5-(5-chlorosulfonyl-2-etoxyphenyl)-1-methyl-3n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one in 900 mL of ethanol absolute. Under stirring and at room temperature, add at only one time, a solution containing 31.0 g (3 Eq., 180 mmol MW=172) of N-piperazine ethyl acetate (Reaction 1) dissolved in 150 mL of ethanol absolute. In an interval of 2–10 minutes, all solid is consumed, forming a clean and homogeneous solution, and after that starts the precipitation of the expected product. At the end of the reaction, which lasts 2–3 hours (monitored by chromatography of thin layer), the product is vacuum filtered and the solid is washed with two portions of 50 mL of iced absolute ethanol. 29 g are obtained (yielding=89%) from the product as a white solid of MP=165.5–166.5° C.

Reaction 7:

Intermediate 1

5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one. IS MONOMER

please note during LAH redn …………. the PIP CH2-C=O-O CH2 CH3 BECOMES PIP-CH2CH2-OH

To a suspension of lithium aluminum hydride (0.74 g 2.2 Eq. MW=37.9) in 25 mL of THF, slowly add, under stirring and at room temperature, a suspension of 5.0 g (9.1 mmol, MW=546.6) of 5-{2-ethoxy-5-[(4-ethyl acetate 1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-di-hydro-7H-pyrazole[4,3-d]pyrimidin-7-one in 50 mL of THF. The system is maintained under stirring, monitoring the consumption of the product by chromatography of thin layer, until the complete consumption of the starting reagent (about 5–6 hours). Slowly add water to the reaction medium and, when there is no longer release of H₂, add HCl 1M regulating pH for 7. Extract the product with 3 200 mL-portions of chloroform, dry with anhydrous sodium sulfate and vacuum concentrate the product. It is obtained 3.8 g of the product as a cream solid MP=183–187° C. yielding 83%. The same was crystallized from methanol and DMF yielding a slightly yellowish solid with melting point at 189–192° C.

note …………. the PIP CH2-C=O-O CH2 CH3 BECOMES PIP-CH2CH2-OH

HOMODIMER CARBONATE

EXAMPLE 1B

Homodimer Carbonate of Intermediate 1—Alternative Method

A phosgene solution (3.5 g, 35 mmol) dissolved in 20 mL of toluene was added dropwise to a solution of 2.02 g (4 mmol) of 5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one, suspended in 44 mL of toluene. The reaction mixture resulting is stirred and followed by chromatography analysis of thin layer every hour until the reagent conversion in its chloroformate was completed. When the analysis indicates the complete consumption of 5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one, the volatile compounds of the reaction are vacuum removed (solvents and phosgene), yielding the esther chloroformate raw derivative of 5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one.

The raw chloroformate obtained above (4.0 mmol, 2.27 g) is dissolved in about 30 mL of dichloromethane, to which is added 2.07 g (4.1 mmol) of 5-{2-ethoxy-5-[(4-hydroxyethyl-1-piperazinyl)sulfonyl]phenyl}-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one, followed by the addition of 4 mL of dichloromethane containing 450 mg of triethylamine. The reaction mixture is maintained under stirring, being followed by chromatography of thin layer every hour until this indicates the end of the reaction (disappearing of chloroformate derivative). The reaction mixture is then diluted with 60 mL of dichloromethane, washed with NaCl saturated solution, after with sodium bicarbonate saturated solution and again with NaCl saturated solution. Organic phase is separated and dry with anhydrous sodium sulfate. The solvent is then evaporated to dry, yielding the dimer carbonate as a slightly yellowish solid.

This compound is re-crystallized from ethanol:DMF, yielding a pale white solid. Yielding m=3.2 g (76%)

Microanalysis: Theoretical C, (54.53%); H, (6.04%); N, (16.24%);

Obtained C, (54.45%); H, (6.02%); N, (16.17%).

INFO ABOUT INTERMEDIATE

5-(5-Chlorosulfonyl-2-ethoxyphenyl)-1-methyl-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one Structure

5-(5-chlorosulfonyl-2-ethoxyphenyl)-1-methyl-3n-propyl-1,6-dihydro-7H-pyrazole[4,3-d]pyrimidin-7-one

CAS No.	139756-22-2
Chemical Name:	5-(5-Chlorosulfonyl-2-ethoxyphenyl)-1-methyl-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one
Synonyms:	Sildenafil Chlorosulfone IMpurity;Sildenafil Chlorosulfonyl IMpurity;5-(5-CHLOROSULFONYL-2-ETHOXY PHENYL)-1-METHYL-3-N-PROPYL-1;3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1 H-pyrazolo-(4-3-d)-pyrimidine-5;5-(5-Chlorosulfonyl-2-ethoxyphenyl)-1-methyl-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one;3-(4,7-Dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxy-benzenesulfonyl Chloride;4-Ethoxy-3-(1-Methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyriMidin-5-yl)benzene-1-sulfonyl chloride
CBNumber:	CB11175931
Molecular Formula:	C17H19ClN4O4S

http://www.chemicalbook.com/ChemicalProductProperty_EN_CB11175931.htm

…………..

SYNTHESIS OF

http://www.google.co.in/patents/US6362178

2-butyrylamino-propionic acid

EXAMPLE 1A 2-Butyrylaminopropionic acid

200 MHz ¹H-NMR (DMSO-d6): 0.84, t, 3H; 1.22, d, 3H; 1.50, hex, 2H; 2.07, t, 2H; 4.20, quin., 1H; 8.09, d, 1H.

EXAMPLE 3A 2-Ethoxybenzonitrile

200 MHz ¹H-NMR (DMSO-d6): 1.48, t, 3H; 4.15, quart., 2H; 6.99, dt, 2H; 7.51, dt, 2H.

2-ethoxybenzamidine hydrochloride

EXAMPLE 4A 2-Ethoxybenzamidine hydrochloride

200 MHz ¹H-NMR (DMSO-d6): 1.36, t, 3H; 4.12, quart., 2H; 7.10, t, 1H; 7.21, d, 1H; 7.52, m, 2H; 9.30, s, broad, 4H.

EXAMPLE 10A 2-(2-Ethoxy-phenyl)-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

200 MHz ¹H-NMR (CDCl₃): 1.02, t, 3H; 1.56, t, 3H; 1.89, hex, 2H; 2.67, s, 3H; 3.00, t, 2H; 4.26, quart., 2H; 7.05, m, 2H; 7.50, dt, 1H; 8.17, dd, 1H; 10.00, s, 1H.

EXAMPLE 15A 4-Ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]triazin-2-yl)-benzenesulphonyl chloride

200 MHz ¹H-NMR (CDCl₃): 1.03, t, 3H; 1.61, t, 2H; 1.92, hex, 2H; 2.67, s, 3H; 3.10, t, 2H; 4.42, quart., 2H; 7.27, t, 1H; 8.20, dd, 1H; 8.67, d, 1H; 10.18, s, 1H.

Example 22 2-[2-Ethoxy-5-(4-hydroxyethyl-1-amino-piperazine-1-sulphonyl)-phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

By the same method, starting with 0.04 g (0.097 mmol) of 4-ethoxy-3-(5-methyl-4-oxo-7-propyl-3,4-dihydro-imidazo[5,1-f][1,2,4]triazin-2-yl)-benzenesulphonyl chloride and 0.04 g (0.29 mmol) of 1-amino-4-hydroxyethylpiperazine, 46 mg (91%) of 2-[2-ethoxy-5-(4-hydroxyethyl-1-amino-piperazine-1-sulphonyl)-phenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one are obtained.

R_f=0.08 (dichloromethane/methanol=19:1)

200 MHz ¹H-NMR (CDCl₃): 1.02, t, 3H; 1.59, t, 3H; 1.90, sex., 2H; 2.49, m, 6H; 2.62, s, 3H; 2.71, m, 4H; 3.00, t, 2H; 3.55, t, 2H; 4.31, quart., 2H; 7.14, d, 1H; 8.05, dd, 1H; 8.60, d, 1H.

…………..

Methods of analysis

The development of lodenafil carbonate was reported by Toque et al. (2008). They observed the effects of lodenafil carbonate on rabbit and human corpus cavernosum relaxation, activity of PDE5 in human platelets, stability and metabolic studies in comparison with sildenafil and lodenafil, as well as the pharmacological evaluation of lodenafil carbonate after intravenous and oral administration in male beagles.

The determination of PDE activity, stability of lodenafil carbonate in human, dog and rat plasma and the pharmacokinetic parameters after a single intravenous or oral dose was carried out by LC-MS/MS analysis

Codevilla et al. (2011a) developed a stability-indicating reversed-phase liquid chromatography method using ultraviolet (UV) detection for the quantitative determination of lodenafil carbonate in tablets. The method can be useful for routine quality control assay and stability studies.

Another study for the determination of lodenafil carbonate in tablets was developed by Codevilla et al. (2011b). As an alternative to the LC method the authors suggested a UV-spectrophotometric method for the analysis of lodenafil carbonate in pharmaceutical form. The UV method offers advantages over other analytical methods due to its rapidity, simplicity, and lower cost. Recently, Codevilla et al. (2012) developed and validated a capillary zone electrophoresis (CZE) method for determination of lodenafil carbonate in drug products. There are some advantages to use the CZE method, such as rapid analysis, small sample and reagent consumption, high separation efficiency (Furlanetto et al., 2001; Yang et al., 2010). The results obtained from the UV-spectrophotometric method and CZE method were compared statistically with the LC method (Codevilla et al., 2011a) and the results showed no significant difference between these methods.

References

Toque HA, Teixeira CE, Lorenzetti R, Okuyama CE, Antunes E, De Nucci G (September 2008). “Pharmacological characterization of a novel phosphodiesterase type 5 (PDE5) inhibitor lodenafil carbonate on human and rabbit corpus cavernosum”. European Journal of Pharmacology 591 (1–3): 189–95. doi:10.1016/j.ejphar.2008.06.055. PMID 18593576.
Cristália Product page. Retrieved on September 16, 2009.
ukmedix Lodenafil article. Retrieved on September 16, 2009.
Glina S, Toscano I, Gomatzky C, de Góes PM, Júnior AN, Claro JF, Pagani E (February 2009). “Efficacy and tolerability of lodenafil carbonate for oral therapy in erectile dysfunction: a phase II clinical trial”. The Journal of Sexual Medicine 6 (2): 553–7. doi:10.1111/j.1743-6109.2008.01079.x.PMID 19040623.
Glina S, Fonseca GN, Bertero EB, Damião R, Rocha LC, Jardim CR, Cairoli CE, Teloken C, Torres LO, Faria GE, da Silva MB, Pagani E (February 2010). “Efficacy and Tolerability of Lodenafil Carbonate for Oral Therapy of Erectile Dysfunction: A Phase III Clinical Trial”. The Journal of Sexual Medicine 7 (5): 1928–1936. doi:10.1111/j.1743-6109.2010.01711.x. PMID 20214718.
Toque H A et al., (2008) European Journal of Pharmacology, 591(1-3):189-95.
Exploring the role of PDE5 inhibition in the treatment of muscular dystrophy
Drugs Fut 2011, 36(4): 321

Prediction of Drug Degradation Pathways leading to Structural Alerts for Potential Genotoxic Impurities

regulatory, Uncategorized Comments Off

Jan 302014

An in-depth analysis of the web-based CambridgeSoft Pharmaceutical Drug Degradation Database, Pharma D3, was conducted in two phases in an attempt to generate some general rules for the prediction of alerting structures for genotoxicity that may arise as a result of degradation. The first phase involved interrogation of the database to determine the nature and frequency of alerting structures present in the degradants. This analysis revealed five functional groups, which account for approximately 70% of the alerting structures found in the degradants within the database: (1) aldehydes; (2) α,β unsaturated carbonyls; (3) aromatic amines, hydroxylamine and its derived esters; (4) epoxides; and (5) polyaromatic hydrocarbons. The second phase of the analysis involved categorizing the major chemical reactions responsible for the generation of the five most prevalent alerting structures. This two-step approach led, in turn, to a proposal for the prediction of functional groups that may have a propensity to degrade to alerting structures not necessarily present in the parent molecule.

Prediction of Drug Degradation Pathways leading to Structural Alerts for Potential Genotoxic Impurities

Stephen P. Raillard, Joel Bercu, Steven W. Baertschi and Christopher M. Riley

Org. Process Res. Dev., 2010, 14 (4), pp 1015–1020

Publication Date (Web): April 21, 2010 (Article)

DOI: 10.1021/op100007q

READ ALL AT

http://pubs.acs.org/doi/full/10.1021/op100007q

Dasantafil for Treatment of Erectile Dysfunction

phase 2, Uncategorized 2 Responses »

Jan 292014

Dasantafil

569351-91-3 CAS NO

405214-79-1 (racemate)

UNII-48P711MI2G, SCH 446132, D03657,

Molecular Formula: C₂₂H₂₈BrN₅O₅

Molecular Weight: 522.39222

Merck & Co. (Originator) IN PHASE 2

THERAPEUTIC CLAIM treatment of erectile dysfunction (phosphodiesterase (PDE) 5 isoenzyme inhibitor)

CHEMICAL NAMES

1H-purine-2,6-dione, 7-[(3-bromo-4-methoxyphenyl)methyl]-1-ethyl-3,7-dihydro-8-[[(1R,2R)-2-hydroxycyclopentyl]amino]-3-(2-hydroxyethyl)
7-(3-bromo-4-methoxybenzyl)-1-ethyl-8-[[(1R,2R)-2-hydroxycyclopentyl]amino]-3-(2-hydroxyethyl)-3,7-dihydro-1H-purine-2,6-dione

7-[(3-bromo-4-methoxyphenyl)methyl]-l-ethyl-8-[[(lR,2R)-2- hydroxycyclopentyl]amino]-3-(2-hydroxyethyl)purine-2,6-dione

Treatment of Erectile Dysfunction , Phosphodiesterase PDE5A Inhibitors

Dasantafil (SCH-446132) is a phosphodiesterase type 5 (PDE5) inhibitor which had been in early clinical development at Merck & Co. for the treatment of erectile dysfunction (ED); however, no recent development has been reported for this research. Phosphodiesterases regulate the tissue concentration of cyclic guanosine monophosphate (cGMP), which in turn triggers smooth muscle relaxation, allowing blood to flow into the penis and resulting in erection. PDE5 is the most abundant phosphodiesterase in the human corpus cavernosum, and as such its inhibition by dasantafil enhances erectile function by increasing the concentration of cGMP.

DASANTAFIL

PDE V inhibitor compounds and their use in treating a variety of physiological conditions are described in a number of patents {e.g., U.S. Pat. Nos. 5,409,934, 5,470,579, 5,939,419 and 5,393,755) and foreign publications (e.g., WO 93/23401 , WO 92/05176, WO 92/05175, and WO 99/24433).

Specific PDE V inhibitors have been found useful for specific indications. For example, the use of PDE V inhibitors for treating impotence has met with commercial success with the introduction of sildenafil citrate, vardenafil, and tadalafil (i.e., Viagra®, Levitra®, and Cialis®, respectively). The chemistry and use of Viagra®, including its mechanism of action in treating erectile dysfunction, are taught in EP 0 702 555 B1. Accordingly, it is an object of this invention to provide a method of using a PDE V inhibitor to treat a patient who has, or is at risk of, congestive heart failure, and/or other cardiovascular conditions.

Processes for preparing PDE V inhibitor compounds can be found in US

6,207,829, US 6,066,735, US 5,955,611 , US 5,939,419, US 5,393,755, US 5,409,934, US 5,470,579, US 5,250,534, WO 02/24698, WO 99/24433, WO 93/23401 , WO 92/05176, WO 92/05175, EP 740,668 and EP 702,555. One type of PDE V inhibitor compound contains a xanthine functionality in its structure. Xanthines can be prepared as described by Peter K. Bridson and Xiaodong Wang in 1 -Substituted Xanthines, Synthesis, 855 (July, 1995), which is incorporated herein by reference in its entirety. WO 02/24698, which is incorporated herein by reference in its entirety, teaches a class of xanthine PDE V inhibitor compounds useful for the treatment of impotence. A general process disclosed therein for preparing xanthine PDE V inhibitor compounds having the formula (I) follows:

(III) (I) (i) reacting a compound having the formula (III) with an alkyl halide in the presence of a base (introduction of R¹¹ or a protected form of R¹¹); (ii) (a) debenzylating and then (b) alkylating the compound resulting from step (i) with an alkyl halide, XCH₂R¹“; (iii) (a) deprotonating and then (b) halogenating the compound resulting from step (ii);

(iv) reacting the compound resulting from step (iii) with an amine having the formula R^lvNH₂; and (v) removing a protecting portion of Rⁿ, if present, on the compound resulting from step (iv) to form the compound having the formula (I). R¹, R”, R^m and R^lv correspond to R¹, R², R³ and R⁴, respectively, in WO02/24698, and are defined therein. WO 02/24698 (pages 44 and 68-73) also teaches a synthesis for the following xanthine compound (identified therein as Compound 13 or Compound 114 of Table II): 1-ethyl-3,7-dihydro-8-[(1 R,2R)- (hydroxycyclopentyl) amino]-3-(2-hydroxyethyl)-7-[(3-bromo-4- methoxyphenyl)methyl]-1 H-purine-2,6-dione:

Compound 13. It would be beneficial to provide an improved process for preparing polycyclic xanthine PDE V inhibitor compounds

………………….

Patent description

Links

WO2006055573A2

entry 129 is dasantafil

Figure imgf000050_0001

…………………

SYNTHESIS

Links

WO2002024698A1

Figure imgf000069_0001

14X^‘ _CHs ^{‘ B}” tX is Experimental Procedure: Compound 114 in Table II (13)

1 (20.0 g, 74.0 mmol) was dissolved in dimethylformamide (370 mL) under nitrogen and (2-bromoethoxy)-terf-butyldimethylsilane (31.8 mL, 148 mmol) was added dropwise. The reaction was stirred at room temperature for 115 hrs., then diluted with ethyl acetate and washed with water several times.

The organic mixture was dried over potassium carbonate, filtered and concentrated under vacuum. Purification via flash chromatography (30/70 ethyl acetate/hexanes) yielded 2 (28.1 g, 88%).

¹H NMR (400 MHz, CDCI₃): δ 7.52 (s, 1 H), 7.29-7.39 (m, 5H), 5.49 (s,

2H), 4.25 (t, 2H, J = 6.0 Hz), 4.07 (q, 2H, J = 7.2 Hz), 3.93 (t, 2H, J =

6.0 Hz), 1.24 (t, 3H, J = 7.2 Hz), 0.75 (s, 9H), 0.08 (s, 6H). HRMS: Calcd for C₂₂H₃₂N₄0₃Si (M+H): 429.2322. Found: 429.2329.

To a solution of 2 (2.10 g, 4.89 mmol) in methanol (375 mL) was added ammonium formate (4.64g, 73.6 mmol) and 20% palladium hydroxide on carbon (980 mg). The reaction was heated to reflux for 1.5 hrs., then cooled to room temperature, filtered and concentrated under vacuum. Purification via flash chromatography (50/50 ethyl acetate/hexanes) yielded 3 (1.26 g, 94%).

¹H NMR (400 MHz, CDCI₃): δ 7.82 (s, 1 H), 4.33 (t, 2H, J = 6.0 Hz), 4.16

(q, 2H, J = 7.2 Hz), 3.99 (t, 2H, J = 6.0 Hz), 1.29 (t, 3H, J = 7.2 Hz),

0.78 (s, 9H), 0.06 (s, 6H). HRMS: Calcd for Cι₅H₂₆N₄O₃Si (M+H): 339.1852. Found: 339.1864. To 3 (970 mg, 2.86 mmol) was added dimethylformamide (25 mL), 3- bromo-4-methoxybenzyl bromide 15 (1.62 g, 5.79 mmol), and potassium carbonate (800 mg, 5.79 mmol) under nitrogen. The reaction mixture was stirred at room temperature for 21 hrs., then diluted with ethyl acetate and washed with water several times. The organic mixture was dried over potassium carbonate, filtered and concentrated under vacuum. Purification by flash chromatography (30/70 ethyl acetate/hexanes) yielded 10 (1.55 g, 100%).

¹H NMR (400 MHz, CDCI₃): δ 7.52 (s, 1 H), 7.51 (d, 1 H, J = 2.4 Hz),

7.30 (dd 1 H, J = 2.0 Hz, J = 8.4 Hz), 6.87 (d, 1 H, J = 8.8 Hz), 5.40 (s,

2H), 4.25 (t, 2H, J = 6.0 Hz), 4.07 (q, 2H, J = 7.0 Hz), 3.93 (t, 2H, J =

6.0 Hz), 3.88 (s, 3H), 1.25 (t, 3H, J = 7.0 Hz), 0.75 (s, 9H), 0.08 (s, 6H).

HRMS: Calcd for C₂₃H₃₃BrN₄O₄Si (M+H): 537.1533. Found: 537.1540.

To solution of 10 (1.50 g, 2.80 mmol) in tetrahydrofuran (24 mL) under nitrogen at -78 °C (dry ice/acetone bath) was added lithium diisopropylamide (2M in THF/heptane, 2.2 mL, 4.33 mmol). After stirring for thirty minutes, 1 ,2- dibromotetrafluoroethane (0.69 mL, 5.77 mmol) was added dropwise over five minutes. The reaction was stirred for 1.25 hrs. at -78 °C then quenched with saturated aqueous sodium bicarbonate and warmed to room temperature.

The mixture was extracted with dichloromethane, dried over potassium carbonate, filtered and concentrated under vacuum. Purification via flash chromatography (30/70 ethyl acetate/hexanes) yielded 11 (600 mg, 34%). ¹H NMR (400 MHz, CDCI₃): δ 7.60 (d, 1 H, J = 2.4 Hz), 7.35 (dd, 1 H, J =

2.0 Hz, J = 8.4 Hz), 6.84 (d, 1 H, J = 8.4 Hz), 5.45 (s, 2H), 4.21 (t, 2H, J = 5.6 Hz), 4.07 (q, 2H, J = 6.8 Hz), 3.90 (t, 2H, J = 5.6 Hz), 3.87 (s, 3H), 1.24 (t, 3H, J = 6.8 Hz), 0.73 (s, 9H), 0.08 (s, 6H). HRMS: Calcd for C₂₃H₃₂Br₂N₄O₄Si (M+H): 615.0638. Found: 615.0633.

To 11 (1.89 g, 3.07 mmol) was added the amino alcohol hydrochloride salt (1.31 g, 12.27 mmol), diisopropylethylamine (15.4 mL), and 1-methyl-2- pyrrolidinone (15.4 mL). The reaction mixture was heated to 160 °C in a sealed tube for 13 hrs., then cooled to room temperature. Water was added, then the mixture was extracted with ethyl acetate and washed with water several times. The organic mixture was dried over potassium carbonate, filtered and concentrated under vacuum. Purification via flash chromatography (3/97 methanol/dichloromethane) yielded 12 (1.77 g, 90%).

¹H NMR (400 MHz, CDCI₃): δ 7.45 (d, 1 H, J = 2.0 Hz), 7.17 (dd, 1 H, J =

2.4 Hz, J = 8.6 Hz), 6.86 (d, 1 H, J = 8.4 Hz), 5.18-4.34 (m, 3H), 4.00- 4.23 (m, 5H), 3.86-3.98 (m, 6H), 3.69-3.79 (m, 1 H), 2.10-2.21 (m, 1 H), 1.99-2.10 (m, 1 H), 1.60-1.84 (m, 3H), 1.32-1.43 (m, 1 H), 1.24 (t, 3H, J = 7.2 Hz), 0.75 (s, 9H), 0.07 (d, 6H, J = 4.0 Hz). HRMS: Calcd for C₂₈H₄₃BrN₅θ₅Si (M+H): 636.2217. Found: 636.2207.

12 (1.77 g, 2.78 mmol) was dissolved in tetrahydrofuran (28 mL) under nitrogen and tetrabutylammonium fluoride (1M in THF, 28 mL) was added dropwise. The reaction was stirred at room temperature for 15 hrs., then diluted with dichloromethane and washed with water several times. The organic mixture was dried over potassium carbonate, filtered and concentrated under vacuum. Purification via flash chromatography (3/97 methanol/dichloromethane) yielded 13 (compound no. 114 in Table II) (760 mg, 52%).

DASANTAFIL

¹H NMR (400 MHz, CDCI₃):

δ 7.47 (d, 1 H, J = 2.0 Hz), 7.19 (dd, 1 H, J =2.0 Hz, J = 8.4 Hz), 6.88 (d, 1 H, J = 8.4 Hz), 5.25 (s, 2H), 5.09 (s, 1H), 4.21-4.27 (m, 3H), 4.06 (q, 2H, J = 7.0 Hz), 3.90-3.97 (m, 3H), 3.89 (s, 1 H), 3.74-3.82 (m, 1 H), 3.08 (s, 1 H), 2.12-2.22 (m, 1 H), 1.98-2.08 (m, 1 H), 1.60-1.86 (m, 3H), 1.33-1.43 (m, 1 H), 1.25 (t, 3H, J = 7.0 Hz),1.06-1.22 (m, 3H). HRMS: Calcd for C₂₂H₂₈BrN₅O₅ (M+H): 522.1352. Found: 522.1346.

2-Bromo-4-methyl anisole 14 (2.2 mL, 14.9 mmol) was dissolved in dichlomethane (30 mL) and N-bromosuccinimide (3.75 g, 16.4 mmol) was added followed by AIBN (26.0 mg). The reaction was heated to reflux for 19 hrs., then cooled to room temperature and the precipitate was filtered off. The filtrate was diluted with dichloromethane and washed with 0.5 M aqueous sodium bicarbonate, followed by water. The organic mixture was dried over sodium sulfate, filtered and concentrated under vacuum to yield 15 (4.16 g,

100%). The benzyl bromide was used as the crude material without further purification.

¹H NMR (400 MHz, CDCI₃): δ 7.59 (d, 1 H, J = 2.0 Hz), 7.30 (dd, 1 H, J =

2.4 Hz, J = 8.4 Hz), 6.85 (d, 1 H, J = 8.4 Hz), 4.37 (s, 2H), 3.90 (s, 3H).

General Synthesis of Compound No. 114 in Table II (13) a) Reacting 1 with an alkyl halide and base to form 2; b) Debenzylation of 2 to form 3; c) Alkylation of 3 with a benzyl halide to form 10; d) Deprotonation of 10 followed. by addition of a brominating agent to form 11 ; e) Displacement of bromo 11 with an amine to form 12; and f) Silyl ether cleavage of 12 to form compound no. 114 in Table II (13).

114 IN TABLE II./(13)

Figure imgf000045_0001

……………

WO2003101992A1

GENERAL SCHEME

Figure imgf000018_0001

SYNTHESIOS

Figure imgf000027_0001

9A 13A DASANTAFIL

SYNTHESIS

Compound 1A:

glycine-A/-r(4-methoxyphenyl)methyl1 ethyl ester

To a mixture of glycine ethyl ester hydrochloride (about 1.4 equiv) and potassium carbonate (about 1.0 equiv) was added anhydrous ethanol. The mixture

was stirred at about 40-45 °C for about 3 hours. Then, p-anisaldehyde (about 1.0

equiv.) was added, and the reaction mixture was stirred for a minimum of about 3 hours to provide an imine (not shown). Upon reaction completion (about <5.0 % p- anisaldehyde remaining by GC analysis), the reaction mixture was cooled to about 0-

10 °C. Then, an aqueous solution of sodium borohydride (about 0.50 equiv) was

added to the reaction mixture at a temperature of between about 0 °C and about 20

°C, and stirred for about 1 hour to provide Compound 1 A. Upon completion of the

reduction reaction, the reaction mixture was quenched with the slow addition of an aqueous solution of aqueous glacial acetic acid. After quenching, the reaction mixture was warmed to room temperature and filtered to remove solids. The filtrate was then concentrated under vacuum, followed by the addition of toluene and water to facilitate layer separation. Aqueous potassium carbonate solution was added to adjust the pH of the mixture to about 8-9. The organic layer was separated and the aqueous layer was extracted with toluene. The combined toluene extracts were concentrated to provide the product in about a 80-85% yield (based on GC and HPLC in solution assay). ¹H NMR 400 MHz (CDCI₃): δ 7.23 (d, J = 8.5 Hz, 2H), 6.85 (d, J = 8.5 Hz, 2H),

4.17 (q, J = 7.1 Hz, 2H), 3.78 (s, 3H), 3.73 (s, 2H), 3.38 (s, 2H), 1.88 (s, br, 1 H), 1.26

(t, J = 7.1 Hz, 3H); ¹³C NMR 100 MHz (CDCI₃): δ 172.8, 159.2, 132.0, 129.9, 114.2,

61.1, 55.6, 53.1 , 50.4, 14.6.

Compound 2:

/V-cvanomethanimidic acid ethyl ester

To cyanamide (about 1.2 mole) was added triethylorthoformate (about 1.33 mole), and the reaction mixture was heated to about 85-95 °C for approximately 2 hours to form Compound 2. Estimated in-solution yield was about 95-100%. The product was optionally purified by vacuum distillation.

¹H NMR 400 MHz (CDCI₃): δ 8.38 (s, 1H), 4.28 (t, J = 6.7 Hz, 2H), 1.29 (t, J =

6.8 Hz, 3H); ¹³C NMR 100 MHz (CDCI₃): δ 171.5, 113.4, 65.5, 13.1.

Compound 3A:

Figure imgf000051_0001

cis- and frans-glvcine Λ/-r(cvanoimino,methyl1-Λ/-r(4- methoxyphenvDmethvπ ethyl ester

A solution of Compound 1A (about 1.0 mole) in toluene was concentrated under vacuum to distill off toluene. Anhydrous tetrahydrofuran (“THF”) was added to the concentrate, then Compound 2 (about 1.2 moles, obtained above) was added to that, and the solution was heated at reflux for about 1 hour. At this stage, the formation of Compound 3A was complete. Estimated in-solution yield was about

95% (about 2:1 mixture of cis and trans isomers). Compound 4A: 1H-imidazole-5-carboxylic acid, 4-amino-1-[(4- methoxyphenvDmethvn ethyl ester

Compound 3A (obtained above) was concentrated by distilling off THF. Then, anhydrous ethanol was added to afford a reaction mixture solution. Separately, potassium t-butoxide (about 0.15 mole) was dissolved in anhydrous ethanol to afford a solution. The potassium t-butoxide solution was added to the reaction mixture solution and heated to about 75-85 °C for about 1 hour. The overall in-solution yield of Compound 4A was about 85-90%.

Figure imgf000051_0002

¹H NMR 400 MHz (CDCI₃): δ 7.16 (s, 1H), 7.08 (d, J = 8.6 Hz, 2H), 6.82 (d, J

=8.7 Hz, 2H), 5.23 (s, 2H), 4.93 (s, br, 2H), 4.23 (q, J = 7.1 , 2H), 3.76 (s, 3H), 1.26 (t,

J = 7.1 Hz, 3H); ¹³C NMR 400 MHz (CDCI₃): δ 160.9, 159.2, 139.0, 128.6, 128.5,

114.0, 101.8, 59.5, 55.2, 50.1 , 14.4.

Compound 5AK:

Figure imgf000052_0001

4A 5AK

1 -ethyl-3,7-dihydro-7-F(4-methoxyphenyl)methvπ-1 H-Purine-2.6- dione potassium salt

The reaction mixture containing Compound 4A in ethanol (obtained above) was added to diglyme and distilled under vacuum to remove the ethanol. After being cooled to room temperature, Λ/-ethylurethane (about 1.2 equiv.) was added and the

reaction mixture was heated to about 110-120 °C. A solution of potassium t-butoxide

(2.2 equiv.) in diglyme was added to the hot solution. The reaction mixture was cooled to room temperature. THF was added to precipitate additional product, which was filtered and washed to provide Compound Salt 5AK in 55-65% overall yield. The wet cake can be used as such for conversion to Compound 6A.

¹H NMR (DMSO-de, 400 MHz): δ 7.73 (s, 1H) 7.31 (d, J = 8.6 Hz , 2H) 6.86 (d,

J = 8.6 Hz, 2H) 5.24 (s, 1 H) 3.88 (q, J = 6.8 Hz, 2H) 3.71 (s, 3H) 1.07 (t, J = 6.8 Hz, 3H); ¹³C NMR (DMSO-d₆, 100 MHz): δ 161.1 , 159.0, 158.4, 157.2, 141.4, 131.0,

129.5, 114.1 , 105.6, 55.4, 48.2, 34.4, 14.3.

Optional Neutralization of Compound Salt 5AK to Compound 5A: Compound 5A: 1-ethyl-3,7-dihvdro-7-r(4-methoχyphenyl,methvπ-1 H-Purine-2,6- dione

The wet cake filtered solid of Compound Salt 5AK (obtained above) was suspended in water and then acidified to a pH of about 5 using glacial acetic acid. The resulting slurry was filtered to obtain the neutralized product, which was then washed with water and dried. The overall isolated yield of neutralized Compound 5A from Compound 1 A was about 45-55%. Spectroscopic data for neutralized Compound 5A was identical to that of Compound Salt 5AK.

Compound 6A:

3-r2-(acetyloxy,ethvn-1-ethyl-3,7-dihvdro-7-r(4- methoxyphenyl,methvπ-1H-purine-2,6-dione

To the wet cake filtered solid of Compound Salt 5AK (obtained above) were added tetrabutylammonium bromide (about 0.05 mole) and 2-bromoethyl acetate

(about 1.2 moles) in THF. After being heated to reflux for about 2 hours, part of the THF was distilled off, and isopropyl alcohol was added to the reaction mixture. The reaction mixture was then concentrated under reduced pressure and cooled to around room temperature. Water was added to precipitate the product. After being cooled to about 0-5 °C for about a few hours, the product was isolated by filtration. The wet cake was washed with aqueous isopropyl alcohol (about 30% in water), and dried under vacuum to afford Compound 6A as a pale yellow solid in about a 45- 55% overall yield (based on Compound 1A). The crude product may be purified further by decolorizing with Darco in methanol, followed by filtration and concentration to afford crystalline Compound 6A.

¹H NMR (CDCI3 , 400 MHz): δ 7.54 (s, 1 H) 7.32 (d, J = 8.6 Hz, 2H) 6.90 (d, J =

8.6 Hz, 2H) 5.43 (s, 2H) 4.41 (m, 2H) 4.38 (m, 2H) 4.10 (q, J = 7.2 Hz, 2H) 3.79 (s,

3H) 1.96 (s, 3H) 1.25 (t, J = 7.2 Hz, 3H); ¹³C NMR (CDCI₃ , 100 MHz): δ 171.1 ,

160.2, 155.3, 151.4, 148.9, 140.9, 130.1 , 127.7, 114.8, 107.5, 61.7, 55.6, 50.2, 42.4, 36.9, 21.2, 13.6.

After Optional Neutralization of Compound Salt 5AK to Compound 5A:

Compound 6A:

3-r2-(acetyloxy.ethvπ-1-ethyl-3,7-dihvdro-7-r.4- methoxyphenyl)methyn-1H-purine-2,6-dione

Acetonitrile was added to a mixture of Compound 5A (about 1.0 mole), anhydrous potassium carbonate (about 1.5 moles) and tetrabutylammonium hydrogen sulfate (about 0.05 mole). 2-bromoethyl acetate (about 1.5 moles) was added in three separate portions (0.72 mole in the beginning, another 0.45 mole after about 2 hours of reaction, and then the remaining 0.33 mole after about another

1 hour of reaction) during the course of the reaction at about 80-85 °C. The total reaction time was about 7 hours. The reaction mixture was cooled to about room temperature and filtered. The filtrate was concentrated. Aqueous isopropanol was added to crystallize the product. The product was filtered, washed with aqueous isopropanol, and dried to provide Compound 6A in about a 75-80% yield. Compound 7A: 8-bromo-1 -ethyl-3-r2-(acetyloxy)ethvπ-3,7-dihvdro-7-r(3-bromo-4- methoxyphenyl)methvπ-1 – -Purine-2,6-dione

Compound 6A (about 1 mole) and NBS (about 2.8 moles) were dissolved in

dry acetonitrile and agitated at about 15-20 °C. To this reaction mixture, a solution of

sulfuric acid (about 0.03 mol) in acetonitrile was added, while maintaining the

reaction temperature below about 25 °C. The reaction mixture was agitated at about

20-25 °C for about 12-15 hours until complete consumption of the starting material

was indicated. The reaction mixture was cooled to about 0-5 °C and a cold (about 5-

10 °C) aqueous solution of sodium sulfite was added, keeping the temperature below

about 10 °C. The reaction was agitated for about 2 hours at about 0-10 °C, and then

filtered. The isolated cake was washed with water, followed by methanol, then dried under a vacuum to obtain Compound 7A in about an 85% yield.

Figure imgf000053_0001

¹H NMR (CDCIs, 400 MHz): D 7.60 (d, J=2.0 Hz, 1H), 7.35 (dd, J=8.4 Hz, 2.0 Hz, 1 H), 6.83 (d, J=8.4 Hz, 1 H), 5.43 (s, 2H), 4.35 (m, 4H), 4.05 (q, J=7.0 Hz, 2H), 3.85 (s, 3H), 1.96 (s, 3H), 1.23 (t, J=7.0 Hz, 3H); ¹³C NMR (CDCI₃, 100 MHz): D 171.0, 156.2, 154.2, 150.8, 148.2, 138.3, 128.9, 128.7, 127.5, 112.1 , 112.0, 109.1 , 61.5, 56.5, 49.3, 42.5, 37.0, 21.0, 13.3. MS (ES) m/e 545.2 (M+H)⁺.

Compound 13A:

1-ethyl-3.7-dihvdro-8-r(1f?,2 )-(hvdroxycvclopentyl)amino1-3-(2- hvdroxyethvπ-7-r(3-bromo-4-methoxyphenvhmethvπ-1/–purine-2.6-dione

Compound 7A (about 1 mole) was combined with (R,R)-2-amino-1- cyclopentanol hydrochloride (Compound 8A, about 1.2 moles) and sodium bicarbonate (about 3 moles). To this reaction mixture was added N,N- dimethylacetamide (“DMA”), and the reaction mixture was agitated at about 135-140 °C for about 15-17 hours until complete consumption of the starting material was

indicated.

Figure imgf000053_0002

Compound 9A is an intermediate that is formed, but not isolated, from the

reaction mixture. The reaction mixture was then cooled to about 45-50 °C, and

tetrabutylammonium hydroxide (about 0.05 moles of about a 40% solution in water) was charged therein, followed by methanol. The reaction mixture was refluxed at

about 80-85 °C for about 8-9 hours until complete deprotection of the acetate group

was indicated. The reaction mixture was cooled to about 40-45 °C and concentrated

under vacuum. The pH of the reaction mixture was adjusted to about 5-6 with dilute

acetic acid, and the reaction mixture was heated to about 55-65 °C, and seeded with

a small amount of Compound 13A. The reaction mixture was then cooled to about

30-35 °C over a period of about 2 hours, and water was added over a period of

about 1 hour. The reaction mixture was further cooled to about 0-5 °C over a period

of about 1 hour, and agitated at that temperature for about 4 hours. The Compound 13A product was isolated by filtration, washed with water and dried to provide about an 85-90% yield.

Figure imgf000054_0002

9A 13A DASANTAFIL

¹H NMR (CDCI₃, 400 MHz): D 7.47 (d, J=2.1 Hz, 1 H), 7.18 (dd, J=8.4 Hz, 2.0 Hz, 1 H), 6.87 (d, J=8.4 Hz, 1H), 5.23 (s, 2H), 5.01 (s, 1 H), 4.22 (m, 2H), 4.15 (m, 1H), 4.05 (q, J=7.0 Hz, 2H), 3.93 (m, 3H), 3.88 (s, 3H), 3.77 (m, 1H), 2.95 (m, 1H), 2.15 (m, 1H), 2.05 (m, 1 H), 1.60-1.80 (m, 4H), 1.35 (m, 1 H), 1.23 (t, J=7.0 Hz, 3H); ¹³C NMR (CDCI₃, 100 MHz): D 156.2, 154.0, 153.5, 151.8, 148.3, 132.6, 129.1 , 127.9, 112.5, 103.2, 79.5, 77.8, 63.2, 61.3, 56.7, 46.5, 45.9, 36.8, 32.9, 31.5, 21.4, 13.8. MS (ES) m/e 523.4 (M+H)⁺. Micronization

INTERPRETATION

¹H NMR (CDCI₃, 400 MHz): DELTA

7.47 (d, J=2.1 Hz, 1 H), SANDWICHED AROM H BETWEEN BROMO AND -CH2-PY RING

7.18 (dd, J=8.4 Hz, 2.0 Hz, 1 H), AROM H ORTHO TO -CH2-PH RING AND PARA TO BROMO

6.87 (d, J=8.4 Hz, 1H), AROM H ORTHO TO O ATOM OF PH RING

5.23 (s, 2H), CH2 OF N-CH2-PH RING

5.01 (s, 1 H), OH OR NH 1H OUT OF 3 NOS

4.22 (m, 2H), OH OR NH 2H OUT OF 3 NOS

4.15 (m, 1H), –NCH2CH2OH 1H OUT OF 4 NOS

4.05 (q, J=7.0 Hz, 2H), CH2 OF NCH2 CH3

3.93 (m, 3H), —NCH2CH2OH 3H OUT OF 4 NOS

3.88 (s, 3H), -OCH3

3.77 (m, 1H), OH-CH OF CYCLOPENTANE RING

2.95 (m, 1H),NH-CH OF CYCLOPENTANE RING

2.15 (m, 1H),

2.05 (m, 1 H), 1H ON CYCLOPENTANE RING

1.60-1.80 (m, 4H), 4H ON CYCLOPENTANE RING

1.35 (m, 1 H), 1 H PARA TO SUBS IN CYCLOPENTANE RING

1.23 (t, J=7.0 Hz, 3H) –NCH2 CH3

………………………..

shark

DASANTAFIL

Links

REFERENCES

1 WANG Y ET AL: “DESIGN AND SYNTHESIS OF XANTHINE ANALOGUES AS POTENT AND SELECTIVE PDE5 INHIBITORS” BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, OXFORD, GB, vol. 12, no. 21, 2002, pages 3149-3152, XP009014973 ISSN: 0960-894X

2. Peter K. Bridson and Xiaodong Wang in 1 -Substituted Xanthines, Synthesis, 855 (July, 1995)

PATENTS

1. WO 2002024698..

2. WO 2003101992..

3.WO 2010062366

4. WO 2007002125

5. WO 2006104870

6. WO 2005051368

7. US 2004167137

8. WO 2003101991

9.WO2006104870A2 , Schering Corp Methods of treating benign prostatic hyperplasia or lower urinary track symptoms by using pde 5 inhibitors

shark

WO2005012303A1 *	Jul 29, 2004	Feb 10, 2005	Kevin B Alton	Metabolite of xanthine phosphodiesterase 5 inhibitor and derivatives thereof useful for treatment of erectile dysfunction
US7312223	Jul 29, 2004	Dec 25, 2007	Schering Corporation	Metabolite of xanthine Phosphodiesterase 5 inhibitor and derivatives thereof useful for treatment of erectile dysfunction

WO2002024698A1 *	Sep 17, 2001	Mar 28, 2002	Schering Corp	Xanthine phosphodiesterase v inhibitors
WO2003020724A1 *	Aug 26, 2002	Mar 13, 2003	Schering Corp	Polycyclic guanine phosphodiesterase v inhibitors
WO2003042216A1 *	Nov 7, 2002	May 22, 2003	Schering Corp	Polycyclic guanine derivative phosphodiesterase v inhibitors
DE4411660A1 *	Apr 5, 1994	Oct 12, 1995	Hoechst Ag	Verwendung von Xanthinderivaten zur Reduktion der pathologischen Hyperreagibilität eosinophiler Granulozyten, neue Xanthinverbindungen und Verfahren zu deren Herstellung
EP0430025A2 *	Nov 20, 1990	Jun 5, 1991	Hokuriku Pharmaceutical Co., Ltd.	Xanthine compound, method for preparing thereof, and a pharmaceutical composition comprising the same
JP3072480A *				Title not available
JP4279586A *				Title not available
JP5001065A *				Title not available
US5728686 *	Oct 31, 1996	Mar 17, 1998	Hoechst Aktiengesellschaft	Alkylxanthine phosphonates and alkylxanthine phosphine oxides and their use as pharmaceuticals
US6214992 *	Jun 4, 1997	Apr 10, 2001	Hoechst Aktiengesellschaft	Use of theophylline derivatives for the treatment and prophylaxis of states of shock, novel xanthine compounds and processes for their preparation

shark

WO2003057200A2 *	13 jan 2003	17 juli 2003	Richard David Carr	Compositions comprising inhibitors of dpp-iv and nep enzymes for the treatment of diabetes
WO2003101991A1 *	30 mei 2003	11 dec 2003	Schering Corp	Xanthine phosphodiesterase v inhibitor polymorphs
WO2006026395A1 *	26 aug 2005	9 maart 2006	Richard Dixon	Endothelin a receptor (eta) antagonists in combination with phosphodiesterase 5 inhibitors (pde5) and uses thereof
US20020169174 *	28 aug 2001	14 nov 2002	Samuel Chackalamannil	Xanthine phosphodiesterase V inhibitors
US20030060627 *	25 jan 2002	27 maart 2003	Jordi Gracia Ferrer	8-Phenyl-6, 9-dihydro-[1,2,4] triazolo[3,4-i]purin-5-one derivatives
US20040063731 *	14 jan 2002	1 april 2004	Hans-Michael Eggenweiler	Pharmaceutical formulation comprising pyrazolo[4,3-d]pyrimidines and endothelin receptor antagonists or thienopyrimidines and endothelin receptor antagonists

US2011142956	6-17-2011	USE OF A PDE 5 INHIBITOR FOR TREATING AND PREVENTING HYPOPIGMENTARY DISORDERS
US7786301	8-32-2010	Process for preparing xanthine phosphodiesterase V inhibitors and precursors thereof
US2009149480	6-12-2009	METHODS OF USING PDE V INHIBITORS FOR THE TREATMENT OF CONGESTIVE HEART FAILURE
US7531544	5-13-2009	Xanthine Phosphodiesterase V Inhibitors
US2009105282	4-24-2009	METHODS OF TREATING BENIGN PROSTATIC HYPERPLASIA OR LOWER URINARY TRACT SYMPTOMS BY USING PDE 5 INHIBITORS
US2009074869	3-20-2009	PHARMACEUTICAL FORMULATIONS
US2008051408	2-29-2008	Use of a Pde 5 Inhibitor for Treating and Preventing Hypopigmentary Disorders
US7312223	12-26-2007	Metabolite of xanthine phosphodiesterase 5 inhibitor and derivatives thereof useful for treatment of erectile dysfunction
US7268141	9-12-2007	Xanthine phosphodiesterase V inhibitors
US2007122355	5-32-2007	RAPIDLY ABSORBING ORAL FORMULATIONS OF PDE 5 INHIBITORS


US7192962	3-21-2007	Xanthine phosphodiesterase V inhibitor polymorphs
US2007037831	2-16-2007	Methods of using PDE 5 inhibitors for the treatment of congestive heart failure
US2007031349	2-9-2007	Rapidly absorbing oral formulations of PDE 5 inhibitors
US2007004745	1-5-2007	Methods of treating benign prostatic hyperplasia or lower urinary tract symptoms by using PDE 5 inhibitors
US7074923	7-12-2006	Process for preparing xanthine phosphodiesterase V inhibitors and precursors thereof
US2006040962	2-24-2006	Pharmaceutical formulations
US2005182077	8-19-2005	Xanthine phosphodiesterase V inhibitors
US2005075349	4-8-2005	Xanthine phosphodiesterase V inhibitors
US6821978	11-24-2004	Xanthine phosphodiesterase V inhibitors
US2004229885	11-19-2004	Xanthine phosphodiesterase V inhibitors

Risk Assessment of Genotoxic Impurities in Marketed Compounds Administered over a Short-Term Duration: Applications to Oncology Products and Implications for Impurity Control Limits

regulatory, Uncategorized Comments Off

Jan 282014

Controlling impurities during drug development improves product quality and minimizes safety risks to the patient. Recent regulatory guidance on genotoxic impurities (GTIs) state that identified GTIs are unusually toxic and require lower reporting, identification, and qualification limits than outlined in the International Conference on Harmonization (ICH) guideline “Impurities in New Drug Substances Q3A(R2).” [ ICH Harmonized Tripartite Guideline: Impurities in New Drug Substances (Q3A), (R2); International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH), 2006.] Patient safety is always the underlying focus, but the overall impurity control strategy is also driven by appropriate “as low as reasonably practicable” (ALARP)(2)procedures that include assessment of process capability and associated analytical techniques. In combination with ALARP, safe and appropriate GTI levels are currently identified using chronic toxicology-based limits calculated under the standard assumption of 70-years for exposure duration. This paper proposes a risk assessment approach for developing GTI limits based on shorter-term exposure durations by highlighting marketed anticancer compounds with limited dosing schedules (e.g., 2 years). These limits are generally higher than the defaulted threshold of toxicological concern (TTC of 1.5 μg/day) and can result in more easily developed and less complex analytical methods. The described approach does not compromise safety and can potentially speed life-saving medicines to patients.

Risk Assessment of Genotoxic Impurities in Marketed Compounds Administered over a Short-Term Duration: Applications to Oncology Products and Implications for Impurity Control Limits

Courtney M. Callis, Joel P. Bercu, Keith M. DeVries, Linda K. Dow, David K. Robbins and David L. Varie

Org. Process Res. Dev., 2010, 14 (4), pp 986–992

Publication Date (Web): June 7, 2010 (Concept Article)

DOI: 10.1021/op1000226

READ AT

http://pubs.acs.org/doi/full/10.1021/op1000226

DOLUTEGRAVIR

Uncategorized Comments Off

Jan 272014

Dolutegravir

2H-Pyrido[1′,2′:4,5]pyrazino[2,1-b][1,3]oxazine-9-carboxamide, N-[(2,4-difluorophenyl)methyl]-3,4,6,8,12,12a-hexahydro-7-hydroxy-4-methyl-6,8-dioxo-, (4R,12aS)

(3R,11aS)—N-[(2,4-Difluorophenyl)methyl]-6-hydroxy-3-methyl-5,7-dioxo-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide

(4R,12aS)-N-(2,4-difluorobenzyl)-7-hydroxy-4-methyl-6,8-dioxo-3,4,6,8,12,12a-hexahydro-2H-pyrido[1′,2′:4,5]pyrazino[2,1-b][1,3]oxazine-9-carboxamide
Trade Name:Tivicay
Synonym:GSK1349572, S-349572, GSK572
Date of Approval: August 12, 2013 (US)
Indication:HIV infection
Drug class: Integrase strand transfer inhibitor
Company: ViiV Healthcare,GlaxoSmithKline

INNOVATOR …ViiV Healthcare
CAS number: 1051375-16-6

MF:C20H19F2N3O5
MW:419.4
Chemical Name: (4R,12aS)-N-[(2,4-difluorophenyl)methyl]-7-hydroxy-4-methyl-6,8-dioxo-3,4,6,8,12,12a- hexahydro-2H-pyrido[1′,2′:4,5]pyrazino[2,1-b][1,3]oxazine-9-carboxamide
Patent: US8129385
Patent expiration date: Oct 5, 2027
PCT patent application: W02006116764

Dolutegravir (DTG, GSK1349572) is an integrase inhibitor being developed for the treatment of human immunodeficiency virus (HIV)-1 infection by GlaxoSmithKline (GSK) on behalf of Shionogi-ViiV Healthcare LLC. DTG is metabolized primarily by uridine diphosphate glucuronyltransferase (UGT)1A1, with a minor role of cytochrome P450 (CYP)3A, and with renal elimination of unchanged drug being extremely low (< 1% of the dose).

The European Commission has on 21 January 2014 Dolutegravir (Tivicay, ViiV) permit as part of combination therapy for the treatment of HIV-infected persons over the age of 12 years.Dolutegravir (Tivicay, ViiV) is an integrase inhibitor, in combination with other antiretroviral drugs in adults and adolescents can be used from 12 years for the treatment of HIV infection.

Source: Communication from the European Commission

Dolutegravir^[1] is a FDA-approved drug^[2] for the treatment of HIV infection. Dolutegravir is an integrase inhibitor. Known as S/GSK1349572 or just “572” the drug is marketed as Tivicay^[3] by GlaxoSmithKline (GSK). In February, 2013 the Food and Drug Administration announced that it would fast track dolutegravir’s approval process.^[4] On August 13, 2013, dolutegravir was approved by the FDA. On November 4, 2013, dolutegravir was approved by Health Canada.^[5]

The oral HIV integrase inhibitor S-349572 was originated by Shionogi-GlaxoSmithKline and Shionogi-ViiV Healthcare. In 2013, the product was approved and launched in the U.S. for the treatment of HIV-1 in adults and children aged 12 years and older, in combination with other antiretroviral agents. A positive opinion was received in the E.U for this indication and, in 2014, approval was attained in Europe for this indication. Registration is pending in Japan.

In 2013, orphan drug designation in Japan was assigned to the compound.

Dolutegravir is approved for use in a broad population of HIV-infected patients. It can be used to treat HIV-infected adults who have never taken HIV therapy (treatment-naïve) and HIV-infected adults who have previously taken HIV therapy (treatment-experienced), including those who have been treated with other integrase strand transfer inhibitors. Tivicay is also approved for children ages 12 years and older weighing at least 40 kilograms (kg) who are treatment-naïve or treatment-experienced but have not previously taken other integrase strand transfer inhibitors.^[6]

Dolutegravir has also been compared head-to-head with a preferred regimen from the DHHS guidelines in each of the three classes (i.e. 1.) nuc + non-nuc, 2.) nuc + boosted PI, and 3.) nuc + integrase inhibitor).

SPRING-2 compared dolutegravir to another integrase inhibitor, raltegravir, with both coformulated with a choice of TDF/FTC orABC/3TC. After 48 weeks of treatment 88% of those on dolutegravir had less than 50 copies of HIV per mL compared to 85% in the raltegravir group, thus demonstrating non-inferiority.^[9]

The FLAMINGO study has been presented at scientific meetings but as of early 2014 has not yet been published. It is an open-label trial of dolutegravir versus darunavir boosted with ritonavir. In this trial 90% of those on dolutegravir based regimens had viral loads < 50 at 48 weeks compared to 83% in the darunavir/r.^[10] This 7% difference was statistically significant for superiority of the dolutegravir based regimens.

Another trial comparing dolutegravir to efavirenz, SINGLE, was the first trial to show statistical superiority to an efavirenz/FTC/TDF coformulated regimen for treatment naive patients.^[11] After 48 weeks of treatment, 88% of the dolutegravir group had HIV RNA levels < 50 copies / mL versus 81% of the efavirenz group. This has led one commentator to predict that it may replace efavirenz as the first line choice for initial therapy as it can also be formulated in one pill, once-a-day regimens.^[12]

Doultegravir has also been studied in patients who have been on previous antiretroviral medications. The VIKING trial looked at patients who had known resistance to the first generation integrase inhibitor raltegravir. After 24 weeks 41% of patients on 50mg dolutegravir once daily and 75% of patients on 50mg twice daily (both along with an optimized background regimen) achieved an HIV RNA viral load of < 50 copies per mL. This demonstrated that there was little clinical cross-resistance between the two integrase inhibitors. ^[13]

Dolutegravir (also known as S/GSK1349572), a second-generation integrase inhibitor under development by GlaxoSmithKline and its Japanese partner Shionogi for the treatment of HIV infection, was given priority review status from the US Food and Drug Administration (FDA) in February, 2013.

GlaxoSmithKline marketed the first HIV drug Retrovir in 1987 before losing out to Gilead Sciences Inc. (GILD) as the world’s biggest maker of AIDS medicines. The virus became resistant to Retrovir when given on its own, leading to the development of therapeutic cocktails.

The new once-daily drug Dolutegravir, which belongs to a novel class known as integrase inhibitors that block the virus causing AIDS from entering cells, is owned by ViiV Healthcare, a joint venture focused on HIV in which GSK is the largest shareholder.

Raltegravir (brand name Isentress) received approval by the U.S. Food and Drug Administration (FDA) on 12 October 2007, the first of a new class of HIV drugs, the integrase inhibitors, to receive such approval. it is a potent and well tolerated antiviral agent. However, it has the limitations of twice-daily dosing and a relatively modest genetic barrier to the development of resistance, prompting the search for agents with once-daily dosing.

Elvitegravir, approved by the FDA on August 27, 2012 as part of theelvitegravir/cobicistat/tenofovir disoproxil fumarate/emtricitabine fixed-dose combination pill (Quad pill, brand name Stribild) has the benefit of being part of a one-pill, once-daily regimen, but suffers from extensive cross-resistance with raltegravir.

Gilead’s Atripla (Emtricitabine/Tenofovir/efavirenz), approved in 2006 with loss of patent protection in 20121, is the top-selling HIV treatment. The $3.2 billion medicine combines three drugs in one pill, two compounds that make up Gilead’s Truvada (Emtricitabine/Tenofovir) and Bristol- Myers Squibb Co.’s Sustiva (Efavirenz).

A three-drug combination containing dolutegravir and ViiV’s older two-in-one treatment Epzicom(Abacavir/Lamivudine, marketed outside US as Kivexa) proved better than Gilead’s market-leading Atripla in a clinical trial released in July, 2012 (See the Full Conference Report Here), suggesting it may supplant the world’s best-selling AIDS medicine as the preferred front-line therapy. In the latest Phase III study, after 48 weeks of treatment, 88% of patients taking the dolutegravir-based regimen had reduced viral levels to the goal compared with 81% of patients taking Atripla. More patients taking Atripla dropped out of the study because of adverse events compared with those taking dolutegravir — 10% versus just 2% — which was the main driver of the difference in efficacy. The result was the second positive final-stage clinical read-out for dolutegravir, following encouraging results against U.S. company Merck & Co’s rival Isentress in April, 2012 (See the Conference Abstract Here)..

Dolutegravir is viewed by analysts as a potential multibillion-dollar-a-year seller, as its once-daily dosing is likely to be attractive to patients. The FDA is scheduled to issue a decision on the drug’s approval by August 17。

TIVICAY contains dolutegravir, as dolutegravir sodium, an HIV INSTI. The chemical name of dolutegravir sodium is sodium (4R,12aS)-9-{[(2,4-difluorophenyl)methyl]carbamoyl}-4-methyl-6,8-dioxo-3,4,6,8,12,12a-hexahydro-2H-pyrido[1′,2′:4,5]pyrazino[2,1-b][1,3]oxazin-7-olate. The empirical formula is C₂₀H₁₈F₂N₃NaO₅ and the molecular weight is 441.36 g/mol. It has the following structural formula:

TIVICAY (dolutegravir) Structural Formula Illustration

Dolutegravir sodium is a white to light yellow powder and is slightly soluble in water.

Each film-coated tablet of TIVICAY for oral administration contains 52.6 mg of dolutegravir sodium, which is equivalent to 50 mg dolutegravir free acid, and the following inactive ingredients: D-mannitol, microcrystalline cellulose, povidone K29/32, sodium starch glycolate, and sodium stearyl fumarate. The tablet film-coating contains the inactive ingredients iron oxide yellow, macrogol/PEG, polyvinyl alcohol-part hydrolyzed, talc, and titanium dioxide.

……………………………………

INTRODUCTION

Among viruses, human immunodeficiency virus (HIV), a kind of retrovirus, is known to cause acquired immunodeficiency syndrome (AIDS). The therapeutic agent for AIDS is mainly selected from a group of reverse transcriptase inhibitors (e.g., AZT, 3TC) and protease inhibitors (e.g., Indinavir), but they are proved to be accompanied by side effects such as nephropathy and the emergence of resistant viruses. Thus, the development of anti-HIV agents having the other mechanism of action has been desired.

On the other hand, a combination therapy is reported to be efficient in treatment for AIDS because of the frequent emergence of the resistant mutant. Reverse transcriptase inhibitors and protease inhibitors are clinically used as an anti-HIV agent, however agents having the same mechanism of action often exhibit cross-resistance or only an additional activity. Therefore, anti-HIV agents having the other mechanism of action are desired.

Under the circumstances above, an HIV integrase inhibitor has been focused on as an anti-HIV agent having a novel mechanism of action (Ref: Patent Documents 1 and 2). As an anti-HIV agent having such a mechanism of action, known are carbamoyl-substituted hydroxypyrimidinone derivative (Ref: Patent Documents 3 and 4) and carbamoyl-substituted hydroxypyrrolidione derivative (Ref: Patent Document 5). Further, a patent application concerning carbamoyl-substituted hydroxypyridone derivative has been filed (Ref: Patent Document 6, Example 8).

Other known carbamoylpyridone derivatives include 5-alkoxypyridine-3-carboxamide derivatives and γ-pyrone-3-carboxamide derivatives, which are a plant growth inhibitor or herbicide (Ref: Patent Documents 7-9).

Other HIV integrase inhibitors include N-containing condensed cyclic compounds (Ref: Patent Document 10).

[Patent Document 1] WO03/0166275
[Patent Document 2] WO2004/024693
[Patent Document 3] WO03/035076
[Patent Document 4] WO03/035076
[Patent Document 5] WO2004/004657
[Patent Document 6] JP Patent Application 2003-32772
[Patent Document 7] JP Patent Publication 1990-108668
[Patent Document 8] JP Patent Publication 1990-108683
[Patent Document 9] JP Patent Publication 1990-96506
[Patent Document 10] WO2005/016927

Patent Document 1 describes compounds (I) and (II), which are useful as anti-HIV drugs and shown by formulae:
This document describes the following reaction formula as a method of producing compound (I).
Furthermore, Patent Documents 2 to 6 describe the following reaction formula as an improved method of producing compound (I).
[NON-PATENT DOCUMENTS]
- [Non-Patent Document 1] Journal of Organic Chemistry, 1991, 56(16), 4963-4967
  
  [Non-Patent Document 2] Science of Synthesis, 2005, 15, 285-387
  
  [Non-Patent Document 3] Journal of Chemical Society Parkin Transaction. 1, 1997, Issue. 2, 163-169

…………………………………………

Dolutegravir synthesis (EP2602260, 2013). LiHMDS as the non-nucleophilic strong base pulling compound 1 carbonyl group proton alpha position with an acid chloride after 2 and ring closure reaction to obtain 3 , 3 via primary amine 4 ring opening ring closure to obtain 5 , NBS the bromine under acidic conditions to obtain aldehyde acetal becomes 6 , 6 of the aldehyde and amino alcohols 7 and turn off the condensation reaction obtained by the ring 8 , alkaline hydrolysis 8 of bromine into a hydroxyl group and hydrolyzable ester obtained 9 after the 10 occurred acid condensation Dolutegravir.

………………………………………………………

Synthesis of Dolutegravir (S/GSK1349572, GSK1349572)

………………………

SYNTHESIS

2H-Pyrido[1′,2′:4,5]pyrazino[2,1-b][1,3]oxazine-9-carboxamide, N-[(2,4-difluorophenyl)methyl]-3,4,6,8,12,12a-hexahydro-7-hydroxy-4-methyl-6,8-dioxo-, (4R,12aS) ………..dolutegravir

PATENT US8129385

Desired isomer

Example Z-1

(3R,11aS)—N-[(2,4-Difluorophenyl)methyl]-6-hydroxy-3-methyl-5,7-dioxo-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide sodium salt

(3R,11aS)—N-[(2,4-Difluorophenyl)methyl]-3-methyl-5,7-dioxo-6-[(phenylmethyl)oxy]-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide. To a solution of 16a (409 mg, 0.87 mmol) in dichloroethane (20 mL) was added (2R)-2-amino-1-propanol (0.14 mL, 1.74 mmol) and 10 drops of glacial acetic acid. The resultant solution was heated at reflux for 2 h. Upon cooling, Celite was added to the mixture and the solvents removed in vacuo and the material was purified via silica gel chromatography (2% CH₃OH/CH₂Cl₂gradient elution) to give (3R,11aS)—N-[(2,4-difluorophenyl)methyl]-3-methyl-5,7-dioxo-6-[(phenylmethyl)oxy]-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide (396 mg, 92%) as a glass. ¹H NMR (CDCl₃) δ 10.38 (m, 1H), 8.42 (s, 1H), 7.54-7.53 (m, 2H), 7.37-7.24 (m, 4H), 6.83-6.76 (m, 2H), 5.40 (d, J=10.0 Hz, 1H), 5.22 (d, J=10.0 Hz, 1H), 5.16 (dd, J=9.6, 6.0 Hz, 1H), 4.62 (m, 2H), 4.41 (m, 1H), 4.33-4.30 (m, 2H), 3.84 (dd, J=12.0, 10.0 Hz, 1H), 3.63 (dd, J=8.4, 7.2 Hz, 1H), 1.37 (d, J=6.0 Hz, 3H); ES⁺MS: 496 (M+1).

(3R,11aS)—N-[(2,4-Difluorophenyl)methyl]-6-hydroxy-3-methyl-5,7-dioxo-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide sodium salt. To a solution of (3R,11aS)—N-[(2,4-difluorophenyl)methyl]-3-methyl-5,7-dioxo-6-[(phenylmethyl)oxy]-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide (396 mg, 0.80 mmol) in methanol (30 mL) was added 10% Pd/C (25 mg). Hydrogen was bubbled through the reaction mixture via a balloon for 2 h. The resultant mixture was filtered through Celite with methanol and dichloromethane.

The filtrate was concentrated in vacuo to give (3R,11aS)—N-[(2,4-difluorophenyl)methyl]-6-hydroxy-3-methyl-5,7-dioxo-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide , DOLUTEGRAVIR as a pink tinted white solid (278 mg, 86%).

¹H NMR (CDCl₃) δ 11.47 (m, 1H), 10.29 (m, 1H), 8.32 (s, 1H), 7.36 (m, 1H), 6.82 (m, 2H), 5.31 (dd, J=9.6, 3.6 Hz, 1H), 4.65 (m, 2H), 4.47-4.38 (m, 3H), 3.93 (dd, J=12.0, 10.0 Hz, 1H), 3.75 (m, 1H), 1.49 (d, J=5.6 Hz, 3H); ES⁺ MS: 406 (M+1).

DOLUTEGRAVIR NA SALT

The above material (278 mg, 0.66 mmol) was taken up in ethanol (10 mL) and treated with 1 N sodium hydroxide (aq) (0.66 ml, 0.66 mmol). The resulting suspension was stirred at room temperature for 30 min. Ether was added and the liquids were collected to provide the sodium salt of the title compound as a white powder (291 mg, 99%). ¹H NMR (DMSO-d₆) δ 10.68 (m, 1H), 7.90 (s, 1H), 7.35 (m, 1H), 7.20 (m, 1H), 7.01 (m, 1H), 5.20 (m, 1H), 4.58 (m, 1H), 4.49 (m, 2H), 4.22 (m, 2H), 3.74 (dd, J=11.2, 10.4 Hz, 1H), 3.58 (m, 1H), 1.25 (d, J=4.4 Hz, 3H).

UNDESIRED ISOMER

Example Z-9

(3S,11aR)—N-[(2,4-Difluorophenyl)methyl]-6-hydroxy-3-methyl-5,7-dioxo-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide sodium salt

The title compound was made in two steps using a similar process to that described in example Z-1. 16a (510 mg, 1.08 mmol) and (25)-2-amino-1-propanol (0.17 mL, 2.17 mmol) were reacted in 1,2-dichloroethane (20 mL) with acetic acid to give (3S,11aR)—N-[(2,4-difluorophenyl)methyl]-3-methyl-5,7-dioxo-6-[(phenylmethyl)oxy]-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide (500 mg, 93%). This material was hydrogenated in a second step as described in example Z-1 to give (3S,11aR)—N-[(2,4-Difluorophenyl)methyl]-6-hydroxy-3-methyl-5,7-dioxo-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide (386 mg, 94%) as a tinted white solid. ¹H NMR (CDCl₃) δ 11.46 (m, 1H), 10.28 (m, 1H), 8.32 (s, 1H), 7.35 (m, 1H), 6.80 (m, 2H), 5.30 (dd, J=10.0, 4.0 Hz, 1H), 4.63 (m, 2H), 4.48-4.37 (m, 3H), 3.91 (dd, J=12.0, 10.0 Hz, 1H), 3.73 (m, 1H), 1.48 (d, J=6.0 Hz, 3H); ES⁺ MS: 406 (M+1). This material (385 mg, 0.95 mmol) was treated with sodium hydroxide (0.95 mL, 1.0 M, 0.95 mmol) in ethanol (15 mL) as described in example Z-1 to provide its corresponding sodium salt (381 mg, 94%) as a white solid. ¹H NMR (DMSO-d₆) δ 10.66 (m, 1H), 7.93 (s, 1H), 7.33 (m, 1H), 7.20 (m, 1H), 7.01 (m, 1H), 5.19 (m, 1H), 4.59 (m, 1H), 4.48 (m, 2H), 4.22 (m, 2H), 3.75 (m, 1 H), 3.57 (m, 1H), 1.24 (d, J=5.6 Hz, 3H).

SYNTHESIS OF INTERMEDIATES

Figure US08129385-20120306-C00090

IN ABOVE SCHEME SYNTHESIS UPTO COMPD 9 MAY BE USEFUL IN SYNTHESIS BUT READERS DISCRETION IS SOUGHT IN THIS ?????????????????

1) Maltol 1 (189 g, 1.5 mol) was dissolved in dimethylformamide (1890 ml), and benzyl bromide (184 ml, 1.5 mol) was added. After the solution was stirred at 80° C. for 15 minutes, potassium carbonate (228 g, 1.65 mol) was added, and the mixture was stirred for 1 hour. After the reaction solution was cooled to room temperature, an inorganic salt was filtered, and the filtrate was distilled off under reduced pressure. To the again precipitated inorganic salt was added tetrahydrofuran (1000 ml), this was filtered, and the filtrate was distilled off under reduced pressure to obtain the crude product (329 g, >100%) of 3-benzyloxy-2-methyl-pyran-4-one 2 as a brown oil.

NMR (CDCl₃) δ: 2.09 (3H, s), 5.15 (2H, s), 6.36 (1H, d, J=5.6 Hz), 7.29-7.41 (5H, m), 7.60 (1H, d, J=5.6 Hz).

2) The compound 2 (162.2 g, 750 mmol) was dissolved in ethanol (487 ml), and aqueous ammonia (28%, 974 ml) and a 6N aqueous sodium hydroxide solution (150 ml, 900 mmol) were added. After the reaction solution was stirred at 90° C. for 1 hour, this was cooled to under ice-cooling, and ammonium chloride (58 g, 1080 mmol) was added. To the reaction solution was added chloroform, this was extracted, and the organic layer was washed with an aqueous saturated sodium bicarbonate solution, and dried with anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, isopropyl alcohol and diethyl ether were added to the residue, and precipitated crystals were filtered to obtain 3-benzyloxy-2-methyl-1H-pyridine-4-one 3 (69.1 g, 43%) as a pale yellow crystal.

NMR (DMSO-d₆) δ: 2.05 (3H, s), 5.04 (2H, s), 6.14 (1H, d, J=7.0 Hz), 7.31-7.42 (5H, m), 7.46 (1H, d, J=7.2 Hz), 11.29 (1H, brs).

3) The above compound 3 (129 g, 699 mmol) was suspended in acetonitrile (1300 ml), and N-bromosuccinic acid imide (117 g, 659 mmol) was added, followed by stirring at room temperature for 90 minutes. Precipitated crystals were filtered, and washed with acetonitrile and diethyl ether to obtain 3-benzyloxy-5-bromo-2-methyl-pyridine-4-ol 4 (154 g, 88%) as a colorless crystal.

NMR (DMSO-d₆) δ: 2.06 (3H, s), 5.04 (2H, s), 7.32-7.42 (5H, m), 8.03 (1H, d, J=5.5 Hz), 11.82 (1H, brs).

4) To a solution of the compound 4 (88 g, 300 mmol), palladium acetate (13.4 g, 60 mmol) and 1,3-bis(diphenylphosphino)propane (30.8 g, 516 mmol) in dimethylformamide (660 ml) were added methanol (264 ml) and triethylamine (210 ml, 1.5 mol) at room temperature. The interior of a reaction vessel was replaced with carbon monoxide, and the material was stirred at room temperature for 30 minutes, and stirred at 80 degree for 18 hours. A vessel to which ethyl acetate (1500 ml), an aqueous saturated ammonium chloride solution (1500 ml) and water (1500 ml) had been added was stirred under ice-cooling, and the reaction solution was added thereto. Precipitates were filtered, and washed with water (300 ml), ethyl acetate (300 ml) and diethyl ether (300 ml) to obtain 5-benzyloxy-4-hydroxy-6-methyl-nicotinic acid methyl ester 5 (44.9 g, 55%) as a colorless crystal.

NMR (DMSO-d₆) δ: 2.06 (3H, s), 3.72 (3H, s), 5.02 (2H, s), 7.33-7.42 (5H, m), 8.07 (1H, s).

5) After a solution of the compound 5 (19.1 g, 70 mmol) in acetic anhydride (134 ml) was stirred at 130° C. for 40 minutes, the solvent was distilled off under reduced pressure to obtain 4-acetoxy-5-benzyloxy-6-methyl-nicotinic acid methyl ester 6 (19.9 g, 90%) as a flesh colored crystal.

NMR (CDCl₃) δ: 2.29 (3H, s), 2.52 (3H, s), 3.89 (3H, s), 4.98 (2H, s), 7.36-7.41 (5H, m), 8.85 (1H, s).

6) To a solution of the compound 6 (46.2 g, 147 mmol) in chloroform (370 ml) was added metachloroperbenzoic acid (65%) (42.8 g, 161 mmol) in portions under ice-cooling, and this was stirred at room temperature for 90 minutes. To the reaction solution was added a 10% aqueous potassium carbonate solution, and this was stirred for 10 minutes, followed by extraction with chloroform. The organic layer was washed with successively with a 10% aqueous potassium carbonate solution, an aqueous saturated ammonium chloride solution, and an aqueous saturated sodium chloride solution, and dried with anhydrous sodium sulfate. The solvent was distilled off under induced pressure, and the residue was washed with diisopropyl ether to obtain 4-acetoxy-5-benzyloxy-6-methyl-1-oxy-nicotinic acid methyl ester 7 (42.6 g, 87%) as a colorless crystal.

NMR (CDCl₃) δ: 2.30 (3H, s), 2.41 (3H, s), 3.90 (3H, s), 5.02 (2H, s), 7.37-7.39 (5H, m), 8.70 (1H, s).

7) To acetic anhydride (500 ml) which had been heated to stir at 130° C. was added the compound 7 (42.6 g, 129 mmol) over 2 minutes, and this was stirred for 20 minutes. The solvent was distilled off under reduced pressure to obtain 4-acetoxy-6-acetoxymethyl-5-benzyloxy-nicotinic acid methyl ester 8 (49.6 g, >100%) as a black oil.

NMR (CDCl₃) δ: 2.10 (3H, s), 2.28 (3H, s), 3.91 (3H, s), 5.07 (2H, s), 5.20 (2H, s), 7.35-7.41 (5H, m), 8.94 (1H, s).

8) To a solution of the compound 8 (46.8 g, 125 mmol) in methanol (140 ml) was added a 2N aqueous sodium hydroxide solution (376 ml) under ice-cooling, and this was stirred at 50° C. for 40 minutes. To the reaction solution were added diethyl ether and 2N hydrochloric acid under ice-cooling, and precipitated crystals were filtered. Resulting crystals were washed with water and diethyl ether to obtain 5-benzyloxy-4-hydroxy-6-hydroxymethyl-nicotinic acid 9 (23.3 g, 68%) as a colorless crystal.

NMR (DMSO-d₆) δ: 4.49 (2H, s), 5.19 (2H, s), 5.85 (1H, brs), 7.14-7.20 (2H, m), 7.33-7.43 (7H, m), 8.30 (1H, s), 10.73 (1H, t, J=5.8 Hz), 11.96 (1H, brs).

9) To a solution of the compound 9 (131 g, 475 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (219 g, 1140 mmol) and 1-hydroxybenzotriazole (128 g, 950 mmol) in dimethylformamide (1300 ml) was added 4-fluorobenzylamine (109 ml, 950 mmol), and this was stirred at 80° C. for 1.5 hours. After the reaction solution was cooled to room temperature, hydrochloric acid was added, followed by extraction with ethyl acetate. The extract was washed with a 5% aqueous potassium carbonate solution, an aqueous saturated ammonium chloride solution, and an aqueous saturated sodium chloride solution, and dried with anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain a mixture (175 g) of 10 and 11. the resulting mixture was dissolved in acetic acid (1050 ml) and water (1050 ml), and zinc (31.1 g, 475 mmol) was added, followed by heating to reflux for 1 hour. After the reaction solution was cooled to room temperature, a 10% aqueous potassium carbonate solution was added, followed by extraction with ethyl acetate. The extract was washed with an aqueous saturated ammonium chloride solution, and an aqueous saturated sodium chloride solution, and dried with anhydrous sodium sulfate. After the solvent was distilled off under reduced pressure, this was washed with diethyl ether to obtain 5-benzyloxy-N-(4-fluoro-benzyl)-4-hydroxy-6-hydroxymethyl-nicotinic acid amide 10 (107 g, 59%) as a colorless crystal.

NMR (DMSO-d₆) δ: 4.45 (2H, d, J=4.3 Hz), 4.52 (2H, d, J=5.8 Hz), 5.09 (2H, s), 6.01 (1H, brs), 7.36-7.43 (5H, m), 8.31 (1H, s), 12.63 (1H, brs).

………………..

SYNTHESIS

EP2602260A1

3H IS DOLUTEGRAVIR

Step 1

N,N-dimethylformamide dimethyl acetal (4.9 ml, 36.5 mmol) was added dropwise to compound 3A (5.0 g, 30.4 mmol) under cooling at 0°C. After stirring at 0°C for 1 hour, 100 ml of ethyl acetate was added to the reaction solution, and the organic layer was washed with a 0.5 N aqueous hydrochloric acid solution (50 ml). The aqueous layer was separated, followed by extraction with ethyl acetate (50 ml). The organic layers were combined, washed with a saturated aqueous solution of sodium bicarbonate and saturated saline in this order, and then dried over anhydrous sodium sulfate. The solvent was distilled off, and the obtained residue was purified by silica gel column chromatography (n-hexane-ethyl acetate: 1:1 (v/v) → ethyl acetate) to obtain 4.49 g (yield: 67%) of compound 3B as an oil.
¹H-NMR (CDCl₃)δ:1.32 (3H, t, J = 7.1 Hz), 2.90 (3H, br s), 3.29 (3H, br s), 4.23 (2H, q, J = 7.1 Hz), 4.54 (2H, s), 7.81 (1H, s).

Step 2

Lithium hexamethyldisilazide (1.0 M solution in toluene, 49 ml, 49.0 mmol) was diluted with tetrahydrofuran (44 ml). A tetrahydrofuran (10 ml) solution of compound 3B (4.49 g, 20.4 mmol) was added dropwise thereto under cooling at -78°C, and a tetrahydrofuran (10 ml) solution of ethyl oxalyl chloride (3.35 g, 24.5 mmol) was then added dropwise to the mixture. The mixture was stirred at -78°C for 2 hours and then heated to 0°C. 2 N hydrochloric acid was added to the reaction solution, and the mixture was stirred for 20 minutes, followed by extraction with ethyl acetate (200 ml x 2). The organic layer was washed with a saturated aqueous solution of sodium bicarbonate and saturated saline and then dried over anhydrous sodium sulfate. The solvent was distilled off, and the obtained residue was purified by silica gel column chromatography (n-hexane-ethyl acetate: 7:3 → 5:5 → 0:10 (v/v)) to obtain 1.77 g (yield: 31%) of compound 3C as a white solid.
¹H-NMR (CDCl₃)δ:1.36-1.46 (6H, m), 4.35-4.52 (8H, m), 8.53 (1H, s).

Step 3

Aminoacetaldehyde dimethyl acetal (0.13 ml, 1.20 mmol) was added to an ethanol (6 ml) solution of compound 3C (300 mg, 1.09 mmol) at 0°C, and the mixture was stirred at 0°C for 1.5 hours, then at room temperature for 18 hours, and at 60°C for 4 hours. The solvent in the reaction solution was distilled off under reduced pressure, and the obtained residue was then purified by silica gel column chromatography (n-hexane-ethyl acetate: 5:5 → 0:10 (v/v)) to obtain 252 mg (yield: 64%) of compound 3D as an oil.
¹H-NMR (CDCl₃)δ:1.36-1.47 (6H, m), 3.42 (6H, s), 3.90 (2H, d, J = 5.2 Hz), 4.37 (3H, q, J = 7.2 Hz), 4.50 (2H, q, J = 7.2 Hz), 8.16 (1H, s).

Step 4

62% H₂SO₄ (892 mg, 5.64 mmol) was added to a formic acid (10 ml) solution of compound 3D (1.02 g, 2.82 mmol), and the mixture was stirred at room temperature for 16 hours. The formic acid was distilled off under reduced pressure. To the residue, methylene chloride was added, and the mixture was pH-adjusted to 6.6 by the addition of a saturated aqueous solution of sodium bicarbonate. The methylene chloride layer was separated, while the aqueous layer was subjected to extraction with methylene chloride. The methylene chloride layers were combined and dried over anhydrous sodium sulfate. The solvent was distilled off to obtain 531.8 mg of compound 3E as a yellow oil.
1H-NMR (CDCl3) δ: 1.28-1.49 (6H, m), 4.27-4.56 (4H, m), 4.84 (2H, s), 8.10 (1H, s), 9.72 (1H, s).

Step 5

Methanol (0.20 ml, 5.0 mmol), (R)-3-amino-butan-1-ol (179 mg, 2.0 mmol), and acetic acid (0.096 ml, 1.70 mmol) were added to a toluene (5 ml) solution of compound 3E (531 mg, 1.68 mmol), and the mixture was heated to reflux for 4 hours. The reaction solution was cooled to room temperature, then diluted with chloroform, and then washed with a saturated aqueous solution of sodium bicarbonate. The aqueous layer was subjected to extraction with chloroform. The chloroform layers were combined, washed with saturated saline, and then dried over anhydrous sodium sulfate. The solvent was distilled off, and the obtained residue was purified by silica gel column chromatography (chloroform-methanol: 100:0 → 90:10) to obtain 309.4 mg of compound 3F as a brown oil.
1H-NMR (CDCl3) δ: 1.40 (3H, t, J = 7.1 Hz), 1.40 (3H, d, J = 7.1 Hz), 1.55-1.61 (1H, m), 2.19-2.27 (1H, m), 4.00 (1H, d, J = 1.5 Hz), 4.03 (1H, d, J = 2.5 Hz), 4.10 (1H, dd, J = 13.2, 6.3 Hz), 4.26 (1H, dd, J = 13.2, 3.8 Hz), 4.38 (2H, q, J = 7.1 Hz), 5.00-5.05 (1H, m), 5.31 (1H, dd, J = 6.4, 3.9 Hz), 8.10 (1H, s).

Step 6

Potassium trimethylsilanolate (333 mg, 2.34 mmol) was added to a 1,2-dimethoxyethane (2 ml) solution of compound 3F (159 mg, 0.47 mmol), and the mixture was stirred at room temperature for 7 hours. 1 N hydrochloric acid and saturated saline were added to the reaction solution, followed by extraction with chloroform. The chloroform layers were combined and dried over anhydrous sodium sulfate. The solvent was distilled off to obtain 34.4 mg (yield: 25%) of compound 3G as an orange powder.
1H-NMR (CDCl3) δ: 1.46 (3H, d, J = 3.5 Hz), 1.58-1.65 (1H, m), 2.26-2.30 (1H,m), 4.06-4.10 (2H, m), 4.31 (1H, dd, J = 13.8, 5.6 Hz), 4.48 (1H, dd, J = 13.6, 3.9 Hz), 5.03 (1H, t, J = 6.4 Hz), 5.36 (1H, dd, J = 5.5, 4.0 Hz), 8.44 (1H, s), 12.80 (1H, s), 14.90 (1H, s).

Step 7

Compound 3G (16 mg, 0.054 mmol) and 2,4-difluorobenzylamine (17 mg, 0.12 mmol) were dissolved in N,N-dimethylformamide (1 ml). To the solution, N,N,N’,N’-tetramethyl-O-(7-aza-benzotriazol-1-yl)uronium hexafluorophosphate (HATU) (53 mg, 0.14 mmol) and N-methylmorpholine (0.031 ml, 0.28 mmol) were added, and the mixture was stirred at room temperature for 16 hours. 2,4-difluorobenzylamine (17 mg, 0.12 mmol), HATU (64 mg, 0.17 mmol), and N-methylmorpholine (0.037 ml, 0.34 mmol) were further added thereto, and the mixture was stirred at room temperature for additional 16 hours. 0.5 N hydrochloric acid was added to the reaction solution, followed by extraction with ethyl acetate. The ethyl acetate layers were combined, washed with 0.5 N hydrochloric acid and then with saturated saline, and then dried over anhydrous sodium sulfate. The solvent was distilled off, and the obtained residue was purified by preparative high-performance liquid chromatography to obtain 12.5 mg (yield: 55%) of compound 3H as an orange solid.
DOLUTEGRAVIR
1H-NMR (DMSO-d6) δ: 1.36 (3H, d, J = 6.9 Hz), 1.55-1.60 (1H, m), 2.01-2.05 (1H, m), 3.92-3.94 (1H, m), 4.04 (1H, t, J = 12.6 Hz), 4.38-4.41 (1H, m), 4.57-4.60 (1H, m), 4.81-4.83 (1H, m), 5.46-5.49 (1H, m), 7.08-7.11 (1H, m), 7.25-7.30 (1H, m), 7.41 (1H, dd, J = 15.3, 8.7 Hz), 8.53 (1H, s), 10.38 (1H, s), 12.53 (1H, s).

ISOMERS OF DOLUTEGRAVIR

Step 1

Acetic acid (180 mg, 3.00 mmol) was added to a toluene (90 ml) solution of compound A-1 (4.39 g, 9.33 mmol) and (R)-3-aminobutan-1-ol (998 mg, 11.2 mmol), and the mixture was stirred at 50°C for 90 minutes. The reaction solution was allowed to cool to room temperature and then poured to a saturated aqueous solution of sodium bicarbonate. The organic layer was separated, while the aqueous layer was subjected to extraction three times with ethyl acetate. The combined extracts were washed with saturated saline and then dried over sodium sulfate. The solvent was distilled off to obtain 4.29 g of crude product A-2.

Step 2

The crude product A-2 obtained in the preceding step was dissolved in ethanol (40 ml). To the solution, a 2 N aqueous sodium hydroxide solution (20 ml) was added at room temperature, and the mixture was stirred at the same temperature for 2 hours. The reaction solution was neutralized to pH 7 using a 2 N aqueous hydrochloric acid solution. The solvent was directly distilled off. The obtained crude product A-3 was subjected to azeotropy with toluene (100 ml) and used in the next step without being purified.

Step 3

HOBt (1.65 g, 12.2 mmol) and WSC HCl (2.34 g, 12.2 mmol) were added at room temperature to a DMF (100 ml) solution of the crude product A-3 obtained in the preceding step, and the mixture was stirred at the same temperature for 15 hours. Water was added to the reaction solution, followed by extraction three times with ethyl acetate. The combined extracts were washed with water three times and then dried over sodium sulfate. The solvent was distilled off, and the obtained oil was subjected to silica gel column chromatography for purification. Elution was performed first with n-hexane-ethyl acetate (3:7, v/v) and then with only ethyl acetate. The fraction of interest was concentrated, and the obtained oil was then dissolved in ethyl acetate. The solution was crystallized with diisopropyl ether as a poor solvent. The obtained crystals were collected by filtration and dissolved again in ethyl acetate. The solution was recrystallized to obtain 1.84 g of compound A-4.
¹HNMR (CDCl₃) δ: 1.49 (3H, d, J = 6.6 Hz), 1.88-1.96 (1H, m), 2.13-2.26 (1H, m), 3.90-4.17 (4H, m), 4.42-4.47 (1H, m), 4.63 (2H, d, J = 6.0 Hz), 5.12-5.17 (1H, m), 5.17 (1H, d, J = 9.9 Hz), 5.33 (1H, d, J = 9.9 Hz), 6.77-6.87 (2H, m), 7.27-7.42 (4H, m), 7.59-7.62 (2H, m), 8.35 (1H, s), 10.41 (1H, t, J = 5.7 Hz).

Step 4

The compound A-4 was subjected to the hydroxy deprotection reaction described in Step F of the paragraph [0088] to obtain compound A-5.
¹HNMR (DMSO-d₆) δ:1.41 (3H, d, J = 6.3 Hz), 1.85-1.92 (1H, m), 1.50-1.75 (1H, m), 4.02-4.09 (3H, m), 4.28-4.34 (1H, m), 4.53 (2H, d, J = 5.7 Hz), 4.64 (1H, dd, J = 3.9 Hz, 12.6 Hz), 5.45 (1H, dd, J = 3.6 Hz, 9.3 Hz), 7.06 (1H, ddd, J = 2.7 Hz, 8.4 Hz, 8.4 Hz), 7.20-7.28 (1H, m), 7.35-7.42 (1H, m), 8.43 (1H, s),10.37 (1H, t, J = 6.0 Hz),12.37 (1H, brs).

Compound A-1 was reacted with (S)-3-aminobutan-1-ol in Step 1. Compound B-5 was obtained in the same way as in Reference Example 1.
¹HNMR (DMSO-d₆) δ:1.41 (3H, d, J = 6.3 Hz), 1.85-1.92 (1H, m), 1.50-1.75 (1H, m), 4.02-4.09 (3H, m), 4.28-4.34 (1H, m), 4.53 (2H, d, J = 5.7 Hz), 4.64 (1H, dd, J = 3.9 Hz, 12.6 Hz), 5.45 (1H, dd, J = 3.6 Hz, 9.3 Hz), 7.06 (1H, ddd, J = 2.7 Hz, 8.4 Hz, 8.4 Hz), 7.20-7.28 (1H, m), 7.35-7.42 (1H, m), 8.43 (1H, s),10.37 (1H, t, J = 6.0 Hz),12.37 (1H, brs).

……………..

W02006116764

Figure imgf000122_0001

ENTRY 68

………………………….

WO 2010068262

…………………………

WO 2010068253

…………………………………

WO 2011119566

…………………………..

WO 2012018065

Example 3

I was under cooling added dropwise at 0 ℃ (4.9 ml, 36.5 mmol) and N, N-dimethylformamide dimethyl acetal (5.0 g, 30.4 mmol) in the first step compound 3A. After stirring for 1 hour at 0 ℃, ethyl acetate was added to 100ml, the reaction mixture was washed with 0.5N aqueous hydrochloric acid (50 ml). Was extracted with ethyl acetate (50ml) and solution was separated and the aqueous layer. The organic layers were combined, washed successively with saturated aqueous sodium bicarbonate solution and saturated brine, and then dried over anhydrous sodium sulfate. After the solvent was distilled off, silica gel column chromatography and the residue obtained was – and purified by (n-hexane (v / v) → ethyl acetate 1:1) to an oil (67% yield) of Compound 3B 4.49 g I got a thing.
¹ H-NMR (CDCl ₃₎ ^δ: 1.32 (3H, t, J = 7.1 Hz), 2.90 (3H, br s), 3.29 (3H, br s), 4.23 (2H, q, J = 7.1 Hz), 4.54 (2H, s), 7.81 (1H, s).
Diluted with tetrahydrofuran (44 ml) (1.0M toluene solution, 49 ml, 49.0 mmol) the second step lithium hexamethyldisilazide, under cooling at -78 ℃, compound 3B (4.49 g, 20.4 mmol) in this After dropwise tetrahydrofuran (10 ml) was added dropwise tetrahydrofuran (3.35 g, 24.5 mmol) of ethyl oxalyl chloride and (10 ml) solution. After stirring for 2 hours at -78 ℃, I was warmed to 0 ℃. After washing (200 ml x 2), saturated aqueous sodium bicarbonate solution and the organic layer with saturated brine After stirring for 20 minutes, extracted with ethyl acetate by adding 2N hydrochloric acid, the reaction solution was dried over anhydrous sodium sulfate. After removal of the solvent, silica gel column chromatography and the residue obtained – was purified (n-hexane (v / v) ethyl acetate 7:3 → 5:5 → 0:10), compound 3C 1.77 g (yield I as a white solid 31%).
¹ H-NMR (CDCl ₃₎ ^{δ :1.36-1} .46 (6H, m), 4.35-4.52 (8H, m), 8.53 (1H, s).
Was added at 0 ℃ (0.13 ml, 1.20 mmol) the aminoacetaldehyde dimethyl acetal ethanol (300 mg, 1.09 mmol) of the third step compound 3C to (6 ml) solution, 1 hour and 30 minutes at 0 ℃, 18 hours at room temperature , then I was stirred for 4 hours at 60 ℃. After the solvent was evaporated under reduced pressure and the reaction mixture by silica gel column chromatography and the residue obtained was – and purified by (n-hexane (v / v) ethyl acetate 5:5 → 0:10), compound 3D 252 mg (yield: I got as an oil 64%) rate.
¹ H-NMR (CDCl ₃₎ ^{δ :1.36-1} .47 (6H, m), 3.42 (6H, s), 3.90 (2H, d, J = 5.2 Hz), 4.37 (3H, q, J = 7.2 Hz), 4.50 (2H, q, J = 7.2 Hz), 8.16 (1H, s).
Was added (892 mg, 5.64 mmol) and ₂ SO ₄ 62-H% formic acid (1.02 g, 2.82 mmol) in a fourth step the compound for 3D (10 ml) solution was stirred at room temperature for 16 hours. Methylene chloride was added to the residue Shi distilled off under reduced pressure and formic acid was adjusted to pH = 6.6 by addition of saturated aqueous sodium bicarbonate. The solution was separated methylene chloride layer was extracted with methylene chloride and the aqueous layer. I was dried over anhydrous sodium sulfate combined methylene chloride layers. The solvent was then distilled off and was obtained as a yellow oil 531.8 mg compound 3E.
1H-NMR (CDCl3) δ: 1.28-1.49 (6H, m), 4.27-4.56 (4H, m), 4.84 (2H, s), 8.10 (1H, s), 9.72 (1H, s).
Amino – – butane – 1 – ol (179 mg, 2.0 mmol), methanol (0.20 ml, 5.0 mmol), (R) -3 toluene (531 mg, 1.68 mmol) in the fifth step to compound 3E (5 ml) solution was added (0.096 ml, 1.70 mmol) acetic acid was heated under reflux for 4 hours. After dilution with chloroform, cooled to room temperature, the reaction mixture was washed with a saturated aqueous sodium bicarbonate solution, and the aqueous layer was extracted with chloroform. After washing with saturated brine combined chloroform layer was dried over anhydrous sodium sulfate. The solvent was then distilled off, silica gel column chromatography and the residue obtained – and (chloroform methanol 100:0 → 90:10), was obtained as a brown oil 309.4 mg compound 3F.
1H-NMR (CDCl3) δ: 1.40 (3H, t, J = 7.1 Hz), 1.40 (3H, d, J = 7.1 Hz), 1.55-1.61 (1H, m), 2.19-2.27 (1H, m), 4.00 (1H, d, J = 1.5 Hz), 4.03 (1H, d, J = 2.5 Hz), 4.10 (1H, dd, J = 13.2, 6.3 Hz), 4.26 (1H, dd, J = 13.2, 3.8 Hz ), 4.38 (2H, q, J = 7.1 Hz), 5.00-5.05 (1H, m), 5.31 (1H, dd, J = 6.4, 3.9 Hz), 8.10 (1H, s).
1,2 (159 mg, 0.47 mmol) in the sixth step compound 3F – was added (333 mg, 2.34 mmol) and potassium trimethylsilanolate dimethoxyethane (2 ml) solution was stirred for 7 hours at room temperature. Brine was added to the 1N-hydrochloric acid to the reaction mixture, followed by extraction with chloroform. The combined chloroform layer was dried over anhydrous sodium sulfate. The solvent was removed by distillation, and I as an orange powder (25% yield) of compound 3G 34.4 mg.
1H-NMR (CDCl3) δ: 1.46 (3H, d, J = 3.5 Hz), 1.58-1.65 (1H, m), 2.26-2.30 (1H, m), 4.06-4.10 (2H, m), 4.31 (1H , dd, J = 13.8, 5.6 Hz), 4.48 (1H, dd, J = 13.6, 3.9 Hz), 5.03 (1H, t, J = 6.4 Hz), 5.36 (1H, dd, J = 5.5, 4.0 Hz) , 8.44 (1H, s), 12.80 (1H, s), 14.90 (1H, s).
2,4 (16 mg, 0.054 mmol) and the seventh step compound 3G – was dissolved in N, N-dimethylformamide (1 ml) (17 mg, 0.12 mmol) difluorobenzyl amine, N, N, N ‘, N was added (0.031 ml, 0.28 mmol) and N-methylmorpholine uronium hexafluorophosphate (HATU) (53 mg, 0.14 mmol), and ‘- tetramethyl-O-(yl 7 – aza – – benzo triazolopyrimidine -1) I was stirred at room temperature for 16 h. 2,4 – was added (0.037 ml, 0.34 mmol) and N-methylmorpholine (64 mg, 0.17 mmol) and (17 mg, 0.12 mmol), HATU difluorobenzylamine, and the mixture was stirred for 16 hours at room temperature. I was extracted with ethyl acetate addition of 0.5N-hydrochloric acid to the reaction mixture. 0.5N-hydrochloric acid and then was washed with saturated brine, and dried over anhydrous sodium sulfate and combined ethyl acetate layer. The solvent was then distilled off, and purified by preparative high performance liquid chromatography residue was obtained as an orange solid (55% yield) of compound 3H 12.5 mg.
1H-NMR (DMSO-d6) δ: 1.36 (3H, d, J = 6.9 Hz), 1.55-1.60 (1H, m), 2.01-2.05 (1H, m), 3.92-3.94 (1H, m), 4.04 (1H, t, J = 12.6 Hz), 4.38-4.41 (1H, m), 4.57-4.60 (1H, m), 4.81-4.83 (1H, m), 5.46-5.49 (1H, m), 7.08-7.11 (1H, m), 7.25-7.30 (1H, m), 7.41 (1H, dd, J = 15.3, 8.7 Hz), 8.53 (1H, s), 10.38 (1H, s), 12.53 (1H, s)

References

[1] American Medical Association (AMA), STATEMENT ON A NONPROPRIETARY NAME ADOPTED BY THE USAN COUNCIL (Dolutegravir) Accessed 3 December 2011.
FDA approves new drug to treat HIV infection http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm364744.htm Aug. 12, 2013
“U.S. FDA approves GlaxoSmithKline’s HIV drug Tivicay”. Reuters. 12 August 2013. Retrieved 13 February 2013.
“GSK wins priority status for new HIV drug in U.S”. Reuters. 16 February 2013. Retrieved 18 February 2013.
“ViiV Healthcare receives approval for Tivicay™ (dolutegravir) in Canada for the treatment of HIV”. Retrieved 11 November 2013.
FDA approves new drug to treat HIV infection http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm364744.htm Aug. 12, 2013
U.S. FDA approves GlaxoSmithKline’s HIV drug Tivicay http://www.reuters.com/article/2013/08/12/us-glaxosmithkline-hivdrug-idUSBRE97B0WU20130812 Mon Aug 12, 2013 6:40pm EDT
“Dolutegravir Prescribing Information”. Retrieved 3 January 2014.
Raffi, F; Jaeger, H; Quiros-Roldan, E; Albrecht, H; Belonosova, E; Gatell, JM; Baril, JG; Domingo, P; Brennan, C; Almond, S; Min, S; extended SPRING-2 Study, Group (Nov 2013). “Once-daily dolutegravir versus twice-daily raltegravir in antiretroviral-naive adults with HIV-1 infection (SPRING-2 study): 96 week results from a randomised, double-blind, non-inferiority trial.”. The Lancet infectious diseases 13 (11): 927–35. PMID 24074642.
Jump up^ http://www.natap.org/2013/ICAAC/ICAAC_24.htm
Walmsley, Sharon L.; Antela, Antonio; Clumeck, Nathan; Duiculescu, Dan; Eberhard, Andrea; Gutiérrez, Felix; Hocqueloux, Laurent; Maggiolo, Franco; Sandkovsky, Uriel; Granier, Catherine; Pappa, Keith; Wynne, Brian; Min, Sherene; Nichols, Garrett (7 November 2013). “Dolutegravir plus Abacavir–Lamivudine for the Treatment of HIV-1 Infection”. New England Journal of Medicine 369 (19): 1807–1818. doi:10.1056/NEJMoa1215541.
Sax, Paul. “SINGLE Study Underscores Waning of the Efavirenz Era — But Probably Just in the USA – See more at:http://blogs.jwatch.org/hiv-id-observations/index.php/single-study-underscores-waning-of-the-efavirenz-era-but-probably-just-in-the-usa/2013/11/06/#sthash.A39SderN.dpuf”. Retrieved 19 December 2013.
Eron, JJ; Clotet, B; Durant, J; Katlama, C; Kumar, P; Lazzarin, A; Poizot-Martin, I; Richmond, G; Soriano, V; Ait-Khaled, M; Fujiwara, T; Huang, J; Min, S; Vavro, C; Yeo, J; VIKING Study, Group (2013 Mar 1). “Safety and efficacy of dolutegravir in treatment-experienced subjects with raltegravir-resistant HIV type 1 infection: 24-week results of the VIKING Study.”. The Journal of infectious diseases 207 (5): 740–8. PMID 23225901.
WO2010011812A1 * Jul 23, 2009 Jan 28, 2010 Smithkline Beecham Corporation Chemical compounds

WO2010011819A1 * Jul 23, 2009 Jan 28, 2010 Smithkline Beecham Corporation Chemical compounds
[NON-PATENT DOCUMENTS]
- - [Non-Patent Document 1] Journal of Organic Chemistry, 1991, 56(16), 4963-4967
  - [Non-Patent Document 2] Science of Synthesis, 2005, 15, 285-387
  - [Non-Patent Document 3] Journal of Chemical Society Parkin Transaction. 1, 1997, Issue. 2, 163-169

…………………

Sources:

Johns, Brian Alvin; Kawasuji, Takashi; Taishi, Teruhiko; Taoda, Yoshiyuki ; Polycyclic carbamoylpyridone derivative having HIV integrase inhibitory activity and their preparation; PCT Int. Appl., WO2006116764, 02 Nov 2006

Johns, Brian Alvin; Weatherhead, Jason Gordon;Tricyclic heterocyclic compounds as antiviral agents and their preparation and use in the treatment of HIV infection; PCT Int. Appl., WO2010011812, 28 Jan 2010

Johns, Brian Alvin; Weatherhead, Jason Gordon; Tricyclic heterocyclic compounds as antiviral agents and their preparation and use in the treatment of HIV infection;PCT Int. Appl., WO2010011819, 28 Jan 2010

Yoshida, Hiroshi; Taoda, Yoshiyuki; Johns, Brian Alvin; Synthesis of fused tricyclic carbamoylpyridone HIV integrase inhibitors and intermediates;PCT Int. Appl.,WO2010068253, 17 Jun 2010

Johns, Brian Alvin; Duan, Maosheng; Hakogi, Toshikazu;Processes and intermediates for fused tricyclic carbamoylpyridone HIV integrase inhibitors;PCT Int. Appl., WO2010068262, 17 Jun 2010

Sumino, Yukihito; Okamoto, Kazuya; Masui, Moriyasu; Yamada, Daisuke; Ikarashi, Fumiya;Preparation of compounds having HIV integrase inhibitory activity; PCT Int. Appl.,WO2012018065, 09 Feb 2012

Kawasuji, Takashi; Johns, Brian A.;Discovery of dolutegravir and S/GSK1265744: Carbamoyl pyridone HIV-1 integrase inhibitors;Abstracts, 64th Southeast Regional Meeting of the American Chemical Society, Raleigh, NC, United States, November 14-17 (2012), SERM-176.

Kawasuji, Takashi; Johns, Brian A.; Yoshida, Hiroshi; Weatherhead, Jason G.; Akiyama, Toshiyuki; Taishi, Teruhiko; Taoda, Yoshiyuki; Mikamiyama-Iwata, Minako; Murai, Hitoshi; Kiyama, Ryuichi; Fuji, Masahiro; Tanimoto, Norihiko; Yoshinaga, Tomokazu; Seki, Takahiro; Kobayashi, Masanori; Sato, Akihiko; Garvey, Edward P.; Fujiwara, Tamio; Carbamoyl Pyridone HIV-1 Integrase Inhibitors. 2. Bi- and Tricyclic Derivatives Result in Superior Antiviral and Pharmacokinetic Profiles;Journal of Medicinal Chemistry (2013), 56(3), 1124-1135

Walmsley S et al. Dolutegravir (DTG; S/GSK1349572) + abacavir/lamivudine once daily statistically superior to tenofovir/emtricitabine/efavirenz: 48-week results – SINGLE (ING114467). 52nd ICAAC, 9-12 September 2012, San Francisco. Abstract H-556b.
http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=e1c18d5b-830f-4b4e-8671-35bcfb20eed5&cKey=af219b7d-2171-46b2-91ef-b8049552c9e5&mKey=%7b6B114A1D-85A4-4054-A83B-04D8B9B8749F%7d
http://www.natap.org/2012/ICAAC/ICAAC_06.htm
http://i-base.info/htb/20381

Raffi F et al. Once-daily dolutegravir (DTG; S/GSK1349572) is non-inferior to raltegravir (RAL) in antiretroviral-naive adults: 48 week results from SPRING-2 (ING113086). 19th International AIDS Conference. 22-27 July 2012, Washington. Late breaker oral presentation THLBB04.
http://pag.aids2012.org/abstracts.aspx?aid=20990

National Institutes of Health (U.S.). A trial comparing GSK1349572 50 mg plus abacavir/lamivudine once daily to Atripla (also called the SINGLE trial). Available from:http://clinicaltrials.gov/ct2/show/NCT01263015.

Stellbrink HJ, Reynes J, Lazzarin A, et al. Dolutegravir in combination therapy exhibits rapid and sustained antiviral response in ARV-naïve adults: 96-week results from SPRING-1 (ING112276) (Abstract 102LB). Paper presented at: 19th Conference on Retroviruses and Opportunistic Infections; 2012 March 5–8; Seattle, WA. Available from:http://www.retroconference.org/2012b/Abstracts/45432.html

DOXOFYLLINE

GENERIC, Uncategorized 1 Response »

Jan 262014

DOXOFYLLINE

LAUNCHED 1987, Istituto Biologico Chemioterapico ABC

69975-86-6 CAS NO

7-(1,3-dioxolan-2-ylmethyl)-1,3-dimethylpurine-2,6-dione

1H-Purine-2,6-dione, 3,7-dihydro-7-(1,3-dioxolan-2-ylmethyl)-1,3-dimethyl- (9CI)

7-(1,3-Dioxolan-2-ylmethyl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione; 7-[1,3-(Dioxolan-d4)-2-ylmethyl)]theophylline; 2-(7�-Theophyllinemethyl)-1,3- dioxolane; ABC 12/3; ABC 1213; Ansimar; Dioxyfilline; Doxophylline; Maxivent; Ventax;

Synonyms

2-(7′-Teofillinmetil)-1,3-diossolano
2-(7′-Teofillinmetil)-1,3-diossolano [Italian]
2-(7′-Theophyllinemethyl)-1,3-dioxolane
5-26-14-00120 (Beilstein Handbook Reference)
7-(1,3-Dioxolan-2-ylmethyl)theophylline

Formula	C₁₁H₁₄N₄O₄
Mol. mass	266.25 g/mol

ABC 12/3
Ansimar
BRN 0561195
Dioxyfilline
Doxofilina
Doxofilina [INN-Spanish]
Doxofylline
Doxofyllinum
Doxofyllinum [INN-Latin]
Doxophylline
EINECS 274-239-6
Maxivent
UNII-MPM23GMO7Z
Ventax

Doxofylline (INN), (also known as doxophylline) is a xanthine derivative drug used in the treatment of asthma.^[1]

Doxofylline is a xanthine molecule that appears to be both bronchodilator and anti-inflammatory with an improved therapeutic window over conventional xanthines such as Theophylline and the evidence supporting the effects of Doxofylline in the treatment of lung diseases

It has antitussive and bronchodilator^[2] effects, and acts as aphosphodiesterase inhibitor.^[3]

In animal and human studies, it has shown similar efficacy to theophylline but with significantly fewer side effects.^[4]

Unlike other xanthines, doxofylline lacks any significant affinity for adenosine receptorsand does not produce stimulant effects. This suggests that its antiasthmatic effects are mediated by another mechanism, perhaps its actions on phosphodiesterase.^[1]

Doxofylline, [7-(1, 3-dioxolan-2-ylmethyl)-3, 7-dihydro-1, 3-dimethyl-1H-purine-2, 6-dione] is a new bronchodilator xanthine based drug which differs from theophylline by the presence of dioxalane group at position 7. It is used in the treatment of bronchial asthma, chronic obstructive pulmonary disease (COPD), and chronic bronchitis . The mechanism of action is similar to that of theophylline in that it inhibits phosphodiesterase (PDE-IV), thereby preventing breakdown of cyclic adenosine monophosphate (cAMP). Increase in cAMP inhibits activation of inflammatory cells resulting in bronchodilating effect [52]. In contrast to theophylline, doxofylline has very low affinity towards adenosine A1 and A2 receptors which explain its better safety profile

Doxofylline (7-(l,3-dioxalan-2-ylmethyl)-theophylline) is a drug derived from theophylline which is used in therapy as a bronchodilator, with anti-inflammatory action, in reversible airway obstruction. It is commonly administered in doses ranging from 800 to 1200 mg per day, orally, according to a dosage which provides for the intake of two to three dosage units per day in order to maintain therapeutically effective haematic levels. The doxofylline tablets commercially available generally contain 400 mg of active ingredient and release almost all the drug within one hour from intake. The half- life of the drug is around 6-7 hours and for this reason several administrations are required during the 24-hour period.

Obviously a drop in haematic concentration of the drug in an asthmatic patient or patient suffering from COPD (chronic obstructive pulmonary disease) can result in serious consequences, in which case the patient must have recourse to rescue medication, such as salbutamol inhalers.

Pharmaceutical techniques for obtaining the modified release of drugs have been known for some time, but no modified release formulation of doxofylline is known. In fact the present inventors have observed that there are significant difficulties in the production of a doxofylline formula that can be administered only once a day and in particular have encountered problems correlated with bioequivalence.

Various attempts to formulate doxofylline in modified release systems, with different known polymers, have not provided the desired results, i.e. a composition that can be administered once a day, bio equivalent to the plasmatic concentration obtained with the traditional compositions currently on sale. In fact currently, dosage units containing 400 mg of active ingredient are currently administered two/three times a day for a daily average of approximately 1000 mg of active ingredient, a dosage considered necessary to maintain the therapeutic haematic levels of doxofylline.

Such a dosage unit is currently marketed by Dr. Reddy’s Laboratories Ltd as DOXOBID and has the following quali-quantitative composition: doxofylline (400 mg), colloidal silicon dioxide (13 mg), corn starch (63 mg), mannitol (40 mg), povidone (7 mg), microcrystalline cellulose (64 mg), talc (30 mg), magnesium stearate (3 mg) and water (0.08 ml).

Xanthine is a dioxypurine that is structurally related to uric acid. Xanthine can be represented by the following structure:

Caffeine, theophylline and theobromine are methylated xanthines. Methylated xanthines such as caffeine and theophylline are typically used for their bronchodilating action in the management of obstructive airways diseases such as asthma. The bronchodilator effects of methylxanthines are thought to be mediated by relaxation of airway smooth muscle. Generally, methylxanthines function by inhibiting cyclic nucleotide phosphodiesterases and antagonizing receptor-mediated actions of adenosine.

Theophylline can be represented by the following structure:

However, when administered intravenously or orally, theophylline has numerous undesired or adverse effects that are generally systemic in nature. It has a number of adverse side effects, particularly gastrointestinal disturbances and CNS stimulation. Nausea and vomiting are the most common symptoms of theophylline toxicity. Moderate toxicity is due to relative epinephrine excess, and includes tachycardia, arrhythmias, tremors, and agitation. Severe toxicity results in hallucinations, seizures, dysrhythmias and hypotension. The spectrum of theophylline toxicity can also include death.

Furthermore, theophylline has a narrow therapeutic range of serum concentrations above which serious side effects can occur. The pharmacokinetic profile of theophylline is dependent on liver metabolism, which can be affected by various factors including smoking, age, disease, diet, and drug interactions.

Generally, the solubility of methylxanthines is low and is enhanced by the formation of complexes, such as that between theophylline and ethylenediamine (to form aminophylline). The formation of complex double salts (such as caffeine and sodium benzoate) or true salts (such as choline theophyllinate) also enhances aqueous solubility. These salts or complexes dissociate to yield the parent methylxanthine when dissolved in aqueous solution. Although salts such as aminophylline have improved solubility over theophylline, they dissociate in solution to form theophylline and hence have similar toxicities.

Dyphylline is a covalently modified derivative of xanthine (1,3, -dimethyl-7-(2,3-dihydroxypropl)xanthine. Because it is covalently modified, dyphylline is not converted to free theophylline in vivo. Instead, it is absorbed rapidly in therapeutically active form. Dyphylline has a lower toxicity than theophylline. Dyphylline can be represented by the following structure:

Dyphylline is an effective bronchodilator that is available in oral and intramuscular preparations. Generally, dyphylline possesses less of the toxic side effects associated with theophylline.

U.S. Pat. No. 4,031,218 (E1-Antably) discloses the use of 7-(2,3-dihydroxypropyl)-1,3-di-n-propylxanthine, a derivative of theophylline, as a bronchodilator. U.S. Pat. No. 4,341,783 (Scheindlin) discloses the use of dyphylline in the treatment of psoriasis and other diseases of the skin by topical administration of dyphylline. U.S. Pat. No. 4,581,359 (Ayres) discloses methods for the management of bronchopulmonary insufficiency by administering an N-7-substituted derivative of theophylline, including dyphylline, etophylline, and proxyphylline.

At present, domestic synthetic Doxofylline composed of two main methods: one is by the condensation of theophylline prepared from acetaldehyde and ethylene glycol, but this method is more complex synthesis of acetaldehyde theophylline, require high periodate oxidation operation. Another is a halogenated acetaldehyde theophylline and ethylene glycol is prepared by reaction of an organic solvent, the method were carried out in an organic solvent, whereby the product Theophylline caused some pollution, conducive to patients taking.

current domestic Doxofylline synthetic methods reported in the literature are: 1, CN Application No. 94113971.9, the name “synthetic drugs Doxofyllinemethod” patents, the patent is determined by theophylline with a 2 – (halomethyl) -1,3 – dimethoxy-dioxolane in a polar solvent, with a base made acid absorbent,Doxofylline reaction step. 2, CN Application No. 97100911.2, entitled “Synthesis of Theophylline,” the patent, the patent is obtained from 7 – (2,2 – dialkoxy-ethyl) theophylline with ethylene glycol in N, N-dimethylformamide solvent with an alkali metal carbonate to make the condensing agent, p-toluenesulfonic acid catalyst in the condensation Doxofylline.

Doxofylline of xanthine asthma drugs, and its scientific name is 7 – (1,3 – dioxolan – ethyl methyl) -3,7 – dihydro-1,3 – dimethyl-1H – purine-2 ,6 – dione. The drug developed by the Italian Roberts & Co. in 1988, listed its tablet tradename Ansimar. This product is compared with similar asthma drugs, high efficacy, low toxicity, oral LD50 in mice is 1.5 times aminophylline, non-addictive. Adenosine and its non-blocking agents, it does not produce bronchial pulmonary side effects, no aminophylline like central and cardiovascular system. U.S. patent (US4187308) reported the synthesis of doxofylline, theophylline and acetaldehyde from ethylene glycol p-toluenesulfonic acid catalyst in the reaction of benzene as a solvent Doxofylline. Theophylline acetaldehyde by the method dyphylline derived reaction with a peroxy periodate or 7 – (2,2 – dialkoxy-ethyl) ammonium chloride aqueous solution in the decomposition of theophylline converted to acetaldehyde theophylline . Former method is relatively complex, and the high cost of using periodic acid peroxide, low yield after France. And theophylline acetaldehyde and ethylene glycol solvent used in the reaction of benzene toxicity, harm to health, and the yield is low, with an average around 70%, not suitable for industrial production.

SYN 1

Theophylline-7-acetaldehyde (I) could react with ethylene glycol (II) in the presence of p-toluenesulfonic acid in refluxing benzene to produce Doxofylline.

SYN 2

Doxofylline can be prepared by N-alkylation of theophylline (I) with bromoacetaldehyde ethylene glycol acetal (II) using Na2CO3 in refluxing H2O (1).

.…………………………………….

Synthesis

US4187308

EXAMPLE

A mixture of 15 g of theophyllineacetic aldehyde, 30 ml of ethylene glycol and 1.5 g of p-toluenesulphonic acid in 600 ml of benzene is heated under reflux in a flask provided with a Marcusson apparatus.

After two hours the separation of the water is complete.

The reaction mixture is washed with 200 ml of a 3.5% aqueous solution of sodium bicarbonate.

The organic phase is dried and concentrated to dryness under reduced pressure, to leave a product residue which is taken up in ethyl ether, separated by filtration and purified by ethanol.

2-(7′-theophyllinemethyl)-1,3-dioxolane is obtained.

M.P. 144

Average yield 70%

Analysis: C.sub.11 H.sub.14 N.sub.4 O.sub.4 : M.W. 266.26: Calculated: C%, 49.62; H%, 5.30; N%, 21.04. Found: C%, 49.68; H%, 5.29; N%, 21.16.

………………………………..

CN102936248A

the reaction is:

a, anhydrous theophylline and bromoacetaldehyde ethylene glycol as the basic raw material, purified water as a solvent with anhydrous sodium carbonate as acid-binding agent;

NMR

Doxofylline

UV (95% C2H5OH, nm) λmax273 (ε9230); λmin244 (ε2190)

IR (KBr, cm-1) 1134 (CO); 1233 (CN) ; 1547 (C = N); 1656 (C = C); 1700 (C = O); 2993 (CH)

1H-NMR [CDCl3, δ (ppm)] 3.399 (s, 3H, N-CH3); 3.586 (S, 3H, N-CH3); 3.815-3.885 (m, 4H, OCH2 × 2); 4.581 (d, 2H, CH2); 5.211 (t, 1H, CH ); 7.652 (S, 1H, CH = N)

13C-NMR [CDCL3, δ (ppm)] 27.88 (CH3); 29.69 (CH3); 47.87 (CH2); 65.37 ( OCH2); 100.76 (CH); 107.26 (C = C); 142.16 (CH = N); 148.22 (C = C); 151.59 (C = O); 155.25 ( C

……………………………

HPLC

http://www.scipharm.at/download.asp?id=1401

…………………..

Cirillo R, Barone D, Franzone JS (1988). “Doxofylline, an antiasthmatic drug lacking affinity for adenosine receptors”. Arch Int Pharmacodyn Ther 295: 221–37.PMID 3245738.
Poggi R, Brandolese R, Bernasconi M, Manzin E, Rossi A (October 1989). “Doxofylline and respiratory mechanics. Short-term effects in mechanically ventilated patients with airflow obstruction and respiratory failure”. Chest 96 (4): 772–8.doi:10.1378/chest.96.4.772. PMID 2791671.
Dini FL, Cogo R (2001). “Doxofylline: a new generation xanthine bronchodilator devoid of major cardiovascular adverse effects”. Curr Med Res Opin 16 (4): 258–68.doi:10.1185/030079901750120196. PMID 11268710.
Sankar J, Lodha R, Kabra SK (March 2008). “Doxofylline: The next generation methylxanthine”. Indian J Pediatr 75 (3): 251–4. doi:10.1007/s12098-008-0054-1.PMID 18376093.
Dali Shukla, Subhashis Chakraborty, Sanjay Singh & Brahmeshwar Mishra. Doxofylline: a promising methylxanthine derivative for the treatment of asthma and chronic obstructive pulmonary disease. Expert Opinion on Pharmacotherapy. 2009; 10(14): 2343-2356, DOI 10.1517/14656560903200667, PMID 19678793
Farmaco, Edizione Scientifica, 1981 , vol. 36, 3 pg. 201 – 219, mp 144 – 144.5 °C
Drugs Fut 1982, 7(5): 301

US6313131	16 feb 2000	6 nov 2001	Upsher-Smith Laboratories, Inc.	Method of kidney treatment
US6348470 *	20 maart 1998	19 feb 2002	Korbonits Dezsoe	Antitussive compositions
US6423719	16 feb 2000	23 juli 2002	Upsher-Smith Laboratories, Inc.	Method for treating benign prostate hyperplasia
CN101647776B	2 sept 2009	20 april 2011	吴光彦	Doxofylline venous injection with small volume as well as preparation method and quality control method thereof
DE3114130A1 *	8 april 1981	28 jan 1982	Abc Ist Biolog Chem Spa	Neue theophyllinylmethyldioxolan-derivate, verfahren zu ihrer herstellung und sie enthaltende pharmazeutische ansaetze
EP0272596A2 *	16 dec 1987	29 juni 1988	ISTITUTO BIOLOGICO CHEMIOTERAPICO “ABC” S.p.A.	Theophyllinemethyldithiolan and theophyllinemethyldithianyl derivates, a method for their preparation and pharmaceutical compositions in which they are included
WO2011146031A1	16 mei 2011	24 nov 2011	Bilgic Mahmut	Pharmaceutical composition comprising n- acetylcysteine and a xanthine
WO2013055302A1	14 mei 2012	18 april 2013	Mahmut Bilgic	Effervescent composition comprising n- acetylcysteine and doxophylline or theophylline

………………………………………………………………………………………..

I n case Images are blocked on your computer, VIEW AT

14-chapter 4.pdf – Shodhganga

shodhganga.inflibnet.ac.in/bitstream/10603/9713/…/14-chapter%204.pdf‎

Although various bioanalytical methods for estimation of doxofylline in …. 1H and 13C-NMR spectra of doxofylline and its degradation products were recorded by….. CLICK ABOVE

SPECTRAL DATA

DOXOFYLLINE
The ESI mass spectrum exhibited a protonated molecular ion peak at m/z 267 in positive ion mode indicating the molecular weight of 266. The tandem mass spectrum showed the fragment ions m/z 223, 181.2, 166.2, 138.1, 124.1 and 87.1.

Inline image 2

Inline image 5

Inline image 6

The FT-IR spectrum, two strong peaks at 1697cm-1 and 1658cm-1 indicated presence of two carbonyl groups. A strong peak at frequency 1546cm-1 indicated presence of C=N stretch. A medium peak at 1232cm-1 was due to C-O stretch

Inline image 3

FT IR

1H and 13C-NMR spectra of doxofylline and its degradation products were recorded by using Bruker NMR 300MHz instrument with a dual broad band probe and z-axis gradients. Spectra were recorded using DMSO-d6 as a solvent and tetramethylsilane as an internal standard.
4.2.6 Validation

Inline image 1

1H NMR

Inline image 4

13 C NMR

COMPARISONS

Inline image 9

Inline image 8

Inline image 7

AVANAFIL

GENERIC, Uncategorized Comments Off

Jan 252014

AVANAFIL

A phosphodiesterase (PDE5) inhibitor, used to treat erectile dysfunction.

fish spelling out Welcome

Avanafil is a new phosphodiesterase-5 inhibitor that is faster acting and more selective than other drugs belonging to the same class. Chemically, it is a derivative of pyrimidine and is only available as the S-enantiomer. FDA approved on April 27, 2012.

CAS RN: 330784-47-9
4-{[(3-chloro-4-methoxyphenyl)methyl]amino}-2-[(2S)-2-(hydroxymethyl)pyrrolidin-1-yl]-N-(pyrimidin-2-ylmethyl)pyrimidine-5-carboxamide

(S)-2-(2-Hydroxymethyl-1-pyrrolidinyl)-4-(3-chloro-4-methoxybenzylamino)-5-[(2-pyrimidinylmethyl)carbamoyl]pyrimidine

4-[[(3-Chloro-4-methoxyphenyl)methyl]amino]-2-[(2S)-2-(hydroxymethyl)-1-pyrrolidinyl]-N-(2-pyrimidinylmethyl)-5-pyrimidinecarboxamide

TA 1790

Molecular Formular: C23H26ClN7O3

Molecular Mass: 483.95064

Stendra
TA 1790
TA-1790
UNII-DR5S136IVO
NDA 202276

INNOVATOR — VIVUS

APPROVED FDA 27/4/2-12

Patent No	Patent Expiry	patent use code
6656935	Sep 13, 2020	U-155
7501409	May 5, 2023

U 155… TREATMENT OF ERECTILE DYSFUNCTION

Exclusivity Code	Exclusivity_Date
NCE	Apr 27, 2017

Stendra (avanafil) was given the green light by the US Food and Drug Administration 27/4/2012, but there has been no launch yet as Vivus has been seeking a partner. The latest data should be attractive to potential suitors and could help Stendra take on other phosphodiesterase type 5 (PDE5) inhibitors, notably Pfizer’s Viagra (sildenafil) but also Eli Lilly’s Cialis (tadalafil) and Bayer’s Levitra (vardenafil).

read all at

http://www.pharmatimes.com/Article/13-06-20/Vivus_ED_drug_gets_to_work_in_less_than_15_mins.aspx

STENDRA (avanafil) is a selective inhibitor of cGMP-specific PDE5.

Avanafil is designated chemically as (S)-4-[(3-Chloro-4-methoxybenzyl)amino]-2-[2-(hydroxymethyl)-1-pyrrolidinyl]-N-(2pyrimidinylmethyl)-5-pyrimidinecarboxamide and has the following structural formula:

STENDRA™ (avanafil)Structural Formula Illustration

Avanafil occurs as white crystalline powder, molecular formula C23H26ClN7O3 and molecular weight of 483.95 and is slightly soluble in ethanol, practically insoluble in water, soluble in 0.1 mol/L hydrochloric acid. STENDRA, for oral administration, is supplied as oval, pale yellow tablets containing 50 mg, 100 mg, or 200 mg avanafil debossed with dosage strengths. In addition to the active ingredient, avanafil, each tablet contains the following inactive ingredients: mannitol, fumaric acid, hydroxypropylcellulose, low substituted hydroxypropylcellulose, calcium carbonate, magnesium stearate, and ferric oxide yellow.

2D image of a chemical structure AVANAFIL

Avanafil is a PDE5 inhibitor approved for erectile dysfunction by FDA on April 27, 2012 ^[1] and by EMA on June 21, 2013.^[2] Avanafil is known by the trademark names Stendra and Spedra and was developed by Vivus Inc. In July 2013 Vivus announced partnership with Menarini Group, which will commercialise and promote Spedra in over 40 European countries plus Australia and New Zealand.^[3] Avanafil acts by inhibiting a specificphosphodiesterase type 5 enzyme which is found in various body tissues, but primarily in the corpus cavernosum penis, as well as the retina. Other similar drugs are sildenafil, tadalafil and vardenafil. The advantage of avanafil is that it has very fast onset of action compared with other PDE5 inhibitors. It is absorbed quickly, reaching a maximum concentration in about 30–45 minutes.^[4] About two-thirds of the participants were able to engage in sexual activity within 15 minutes.^[4]

Avanafil is a highly selective PDE5 inhibitor that is a competitive antagonist of cyclic guanosine monophosphate. Specifically, avanafil has a high ratio of inhibiting PDE5 as compared with other PDE subtypes allowing for the drug to be used for ED while minimizing adverse effects. Absorption occurs quickly following oral administration with a median Tmax of 30 to 45 minutes and a terminal elimination half-life of 5 hours. Additionally, it is predominantly metabolized by cytochrome P450 3A4. As such, avanafil should not be co-administered with strong cytochrome P450 3A4 inhibitors. Dosage adjustments are not warranted based on renal function, hepatic function, age or gender. Five clinical trials suggest that avanafil 100 and 200 mg doses are effective in improving the Sexual Encounter Profile and the Erectile Function Domain scores among men as part of the International Index of Erectile Function. A network meta-analysis comparing the PDE5 inhibitors revealed avanafil was less effective on Global Assessment Questionnaire question 1 while safety data indicated no major differences among the different PDE5 inhibitors. The most common adverse effects reported from the clinical trials associated with avanafil were headache, flushing, nasal congestion, nasopharyngitis, sinusitis, and dyspepsia.

A “phosphodiesterase type 5 inhibitor” or “PDE5 inhibitor” refers to an agent that blocks the degradative action of phosphodiesterase type 5 on cyclic GMP in the arterial wall smooth muscle within the lungs and in the smooth muscle cells lining the blood vessels supplying the corpus cavernosum of the penis. PDE5 inhibitors are used for the treatment of pulmonary hypertension and in the treatment of erectile dysfunction. Examples of PDE5 inhibitors include, without limitation, tadalafil, avanafil, lodenafil, mirodenafil, sildenafil citrate, vardenafil and udenafil and pharmaceutically acceptable salts thereof.

“Avanafil” refers to the chemical compound 4-[(3-Chloro-4-methoxybenzyl)amino]-2-[2-(hydroxymethyl)-1-pyrrolidinyl]-N-(2-pyrimidinylmethyl)-5-pyrimidinecarboxamide, and its pharmaceutically acceptable salts. Avanafil is described in Limin M. et al., (2010) Expert Opin Investig Drugs, 19(11):1427-37. Avanafil has the following chemical formula:

Avanafil is being developed for erectile dysfunction. Avanafil currently has no trademarked term associated with it but it is being developed by Vivus Inc.

…………………………………

DESCRIPTION IN A PATENT

US6797709

EXAMPLE 92-145

The corresponding starting compounds are treated in a similar manner to give the compounds as listed in the following Table 7.

TABLE 7

Amorphous MS(m/z): 484(MH⁺)

ENTRY 98 IS AVANAFIL

…………………………………………………….

/CN103254180A

The invention discloses a preparation method of Avanafil (Avanafil, I), which comprises the following steps: carrying out a substitution reaction on 6-amino-1, 2-dihydro pyrimidine-2-keto-5-carboxylic acid ethyl ester (XII) and 3-chloro-4-methoxy benzyl chloride (XIII) so as to obtain 6-(3-chloro-4-methoxy benzyl amino)-1, 2-dihydro pyrimidine-2-keto-5-carboxylic acid ethyl ester (IXV); carrying out condensation on the compound (IXV) and S-hydroxymethyl pyrrolidine (II) so as to generate 4-[(3-chloro-4-methoxy benzyl) amino]-2-[2-(hydroxymethyl)-1-pyrrole alkyl] pyrimidine-5-carboxylic acid ethyl ester (XI); and carrying out hydrolysis on the compound (XI) and then carrying out an acylation reaction on the compound (XI) and the compound (XI) so as to obtain Avanafil (I). The preparation method is simple in process, economic and environmental-friendly, suitable for the requirements of industrialization amplification.

……………………………………………………

/CN103265534A

The invention discloses a method for preparing avanafil (Avanafil, I). The method comprises the steps of taking cytosine as an initial material; and orderly carrying out replacement, halogen addition and condensation reaction on a side chain 3-chlorine-4-methoxy benzyl halide (III), N-(2-methylpyrimidine) formamide (IV) and S-hydroxymethyl pyrrolidine (II), so as to obtain a target product avanafil (I). The preparation method is available in material, concise in technology, economic and environment-friendly, and suitable for the demands of industrial amplification.

…………………………………………………….

SYNTHESIS

Avanafil can be synthesized from a benzylamine derivative and a pyrimidine derivative REF 5:Yamada, K.; Matsuki, K.; Omori, K.; Kikkawa, K.; 2004, U.S. Patent 6,797,709

………………………………………………………

SYNTHESIS

A cutting that phenanthrene by a methylthio urea ( a ) and ethoxy methylene malonate ( 2 ) cyclization of 3 , chloride, phosphorus oxychloride get 4 , 4 with benzyl amine 5 occurred SNAr the reaction product after oxidation with mCPBA 6 . In pyrimidine, if the 2 – and 4 – positions are active simultaneously the same leaving group in the case, SNAr reaction occurs preferentially at 4 – position, but does not guarantee the 2 – side reaction does not occur. Here is an activity of the poor leaving group sulfide spans 2 – bit, and a good leaving group active chlorine occupy four – position, thus ensuring a high regioselectivity of the reaction. 4 – position after completion of the reaction, then the 2 – position of the group activation, where sulfide sulfoxide better than the leaving group. Amino alcohols 7 and 6 recurrence SNAr reaction 8 , 8 after alkaline hydrolysis and acid alpha amidation get that phenanthrene.

AVANAFIL

…………………………….

FDA approves Stendra for erectile dysfunction” (Press release). Food and Drug Administration (FDA). April 27, 2012.
http://www.ema.europa.eu/ema/index.jsp?curl=pages/medicines/human/medicines/002581/human_med_001661.jsp&mid=WC0b01ac058001d124
http://ir.vivus.com/releasedetail.cfm?releaseid=775706
Kyle, Jeffery; Brown, Dana (2013). “Avanafil for Erectile Dysfunction”. Annals of Pharmacotherapy (Sage Publishing). doi:10.1177/1060028013501989. Retrieved 28 September 2013.
Yamada, K.; Matsuki, K.; Omori, K.; Kikkawa, K.; 2004, U.S. Patent 6,797,709
- Peterson CA. Hemodynamic effect of avanafil and glyceryl trinitrate coadministration. , Drugs Context , Volume 2013 , 2013 Feb 26
- Gur S. The Effect of Intracavernosal Avanafil, a Newer Phosphodiesterase-5 Inhibitor, on Neonatal Type 2 Diabetic Rats With Erectile Dysfunction. , Urology , 2013 Dec 9
- Hill JK. Avanafil for erectile dysfunction. , Ann Pharmacother , Volume 47 , Issue 10 , 2013 Oct
- Sanford M. Avanafil: a review of its use in patients with erectile dysfunction. , Drugs Aging , Volume 30 , Issue 10 , 2013 Oct
- Hellstrom WJ. PDE5 inhibitors: considerations for preference and long-term adherence. , Int J Clin Pract , Volume 67 , Issue 8 , 2013 Aug
- Aversa A. An update on pharmacological treatment of erectile dysfunction with phosphodiesterase type 5 inhibitors. , Expert Opin Pharmacother , Volume 14 , Issue 10 , 2013 Jul
- Oelke M. Phosphodiesterase inhibitors in clinical urology. , Expert Rev Clin Pharmacol , Volume 6 , Issue 3 , 2013 May
- Kukreja RC. Sildenafil and cardioprotection. , Curr Pharm Des , Volume 19 , Issue 39 , 2013
- Day WW. An open-label, long-term evaluation of the safety, efficacy and tolerability of avanafil in male patients with mild to severe erectile dysfunction. , Int J Clin Pract, Volume 67 , Issue 4 , 2013 Apr
- Tang J. Comparative effectiveness and safety of oral phosphodiesterase type 5 inhibitors for erectile dysfunction: a systematic review and network meta-analysis. , Eur Urol , Volume 63 , Issue 5 , 2013 May

United States	APPROVED 6656935	2012-04-27	EXPIRY 2020-09-13
United States	7501409	2012-04-27	2023-05-05

Faster-Working Erectile Dysfunction Drug?. CBS News. November 24, 2009.
Vivus says men taking avanafil were more likely to be ready for sex within 15 minutes. The Gaea Times. January 11, 2010.
“Avanafil is the New Player in The Erectile Dysfunction Field”. June 28, 2011.

• Hatzimouratidis, K., et al.: Drugs, 68, 231 (2008)

US7927623	4-20-2011	Tablets quickly disintegrated in oral cavity
US2010179131	7-16-2010	Combination treatment for diabetes mellitus
US2009215836	8-28-2009	Roflumilast for the Treatment of Pulmonary Hypertension
US2008027037	1-32-2008	Cyclic compounds

US5242391	Oct 30, 1991	Sep 7, 1993	ALZA Corporation	Urethral insert for treatment of erectile dysfunction
US5474535	Jul 19, 1993	Dec 12, 1995	Vivus, Inc.	Dosage and inserter for treatment of erectile dysfunction
US5773020	Oct 28, 1997	Jun 30, 1998	Vivus, Inc.	Treatment of erectile dysfunction
US6656935	Aug 10, 2001	Dec 2, 2003	Tanabe Seiyaku Co., Ltd.	Aromatic nitrogen-containing 6-membered cyclic compounds

EXTRAS

“Tadalafil” or “TAD” is described in U.S. Pat. Nos. 5,859,006 and 6,821,975. It refers to the chemical compound, (6R-trans)-6-(1,3-benzodioxol-5-yl)-2,3,6,7,12,12a-hexahydro-2-methyl-pyrazino[1′,2′:1,6]pyrido[3,4-b]indole-1,4-dione and has the following chemical formula:

Tadalafil is currently marketed in pill form for treating erectile dysfunction (ED) under the trade name Cialis® and under the trade name Adcirca® for the treatment of PAH.

Avanafil is being developed for erectile dysfunction. Avanafil currently has no trademarked term associated with it but it is being developed by Vivus Inc.

“Lodenafil” refers to the chemical compound, bis-(2-{4-[4-ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-benzenesulfonyl]piperazin-1-yl}-ethyl)carbonate and has the following chemical formula:

More information about lodenafil is available at Toque H A et al., (2008) European Journal of Pharmacology, 591(1-3):189-95. Lodenafil is manufactured by Cristália Produtos Químicose Farmacêuticos in Brazil and sold there under the brand-name Helleva®. It has undergone Phase III clinical trials, but is not yet approved for use in the United States by the U.S. FDA.

“Mirodenafil” refers to the chemical compound, 5-Ethyl-3,5-dihydro-2-[5-([4-(2-hydroxyethyl)-1-piperazinyl]sulfonyl)-2-propoxyphenyl]-7-propyl-4H-pyrrolo[3,2-d]pyrimidin-4-one and has the following chemical formula:

More information about mirodenafil can be found at Paick J S et al., (2008) The Journal of Sexual Medicine, 5 (11): 2672-80. Mirodenafil is not currently approved for use in the United States but clinical trials are being conducted.

“Sildenafil citrate,” marketed under the name Viagra®, is described in U.S. Pat. No. 5,250,534. It refers to 1-[4-ethoxy-3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)phenylsulfonyl]-4-methylpiperazine and has the following chemical formula:

Sildenafil citrate, sold as Viagra®, Revatio® and under various other trade names, is indicated to treat erectile dysfunction and PAH.

“Vardenafil” refers to the chemical compound, 4-[2-Ethoxy-5-(4-ethylpiperazin-1-yl)sulfonyl-phenyl]-9-methyl-7-propyl-3,5,6,8-tetrazabicyclo[4.3.0]nona-3,7,9-trien-2-one and has the following chemical formula:

Vardenafil is described in U.S. Pat. Nos. 6,362,178 and 7,696,206. Vardenafil is marketed under the trade name Levitra® for treating erectile dysfunction.

“Udenafil” refers to the chemical compound, 3-(1-methyl-7-oxo-3-propyl-4,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-N-[2-(1-methylpyrrolidin-2-yl)ethyl]-4-propoxybenzenesulfonamide and has the following chemical formula:

More information about udenafil can be found at Kouvelas D. et al., (2009) Curr Pharm Des, 15(30):3464-75. Udenafil is marketed under the trade name Zydena® but not approved for use in the United States.

Links

ANTHONY MELVIN CRASTO

THANKS AND REGARD’S

DR ANTHONY MELVIN CRASTO Ph.D GLENMARK SCIENTIST , NAVIMUMBAI, INDIA

did you feel happy, a head to toe paralysed man’s soul in action for you round the clock need help, email or call me

amcrasto@gmail.com

MOBILE-+91 9323115463

web link

http://about.me/amcrasto http://anthonymelvincrasto.brandyourself.com/

I was paralysed in dec2007, Posts dedicated to my family, my organisation Glenmark, Your readership keeps me going and brings smiles to my family

Tezosentan disodium for pulmonary hypertension

Uncategorized Comments Off

Jan 242014

TEZOSENTAN

180384-57-0 CAS OF FREE ACID

N-[6-(2-Hydroxyethoxy)-5-(2-methoxyphenoxy)-2-[2-(2H-tetrazol-5-yl)pyridin-4-yl]pyrimidin-4-yl]-5-propan-2-ylpyridine-2-sulfonamide

5-isopropyl-pyridine-2-sulphonic acid 6-(2-hydroxy-ethoxy)-5- (2-methoxy-phenoxy)-2-(2-1 H-tetrazol-5-yl-pyridin-4-yl)- pyrimidin-4-ylamide

Formula	C₂₇H₂₇N₉O₆S
Mol. mass	605.624

…………………………………………………………………………….

Tezosentan disodium, Ro-61-0612, Veletri

5-isopropyl-pyridine-2-sulfonic acid [6-(2-hydroxy-ethoxy)-5-(2-methoxy-phenoxy)-2-[2-(1H-tetrazole-5-yl)-pyridine-4-yl]-pyrimidine-4-yl]-amide sodium salt (1:2)

180384-58-1 of disodium salt, 180384-57-0 (free acid)

MF C27-H25-N9-O6-S.2-Na

MW 649.5975

Roche (Originator), Actelion (Licensee), Genentech (Codevelopment)

CARDIOVASCULAR DRUGS, Heart Failure Therapy, Renal Failure, Agents for, RENAL-UROLOGIC DRUGS, Treatment of Renal Diseases, Endothelin ETA Receptor Antagonists, Endothelin ETB Receptor Antagonists

Phase III

TEZOSENTAN

Tezosentan is a non-selective ET_A and ET_B receptor antagonist.^[1] It acts as a vasodilator and was designed as a therapy for patients with acuteheart failure. Recent studies have shown however, that tezosentan does not improve dyspnea or reduce the risk of fatal or nonfatal cardiovascular events.^[2]

Pulmonary disease (COPD), which may possibly be associated with pulmonary hypertension, as well as allergic and non-allergic rhinitis, provided that treatment with endothelin from a therapeutic standpoint is not contraindicated.

Tezosentan disodium is an endothelin ETB receptor antagonist in phase II clinical development for the treatment of stable, chronic pulmonary arterial hypertension. The drug was previously being evaluated for heart failure, but trials in that indication have been discontinued. The compound is being developed by Actelion.

………………………………..

SYNTHESIS

………………………………..

SYNTHESIS

Reaction of 4-cyano-pyridine (I) with Na in methanol followed by treatment with ammonium chloride provides 4-amidino-pyridine hydrochloride (II), which is then converted into 5-(2-methoxyphenoxy)-2-(pyridin-4-yl)-pyrimidine-4,6-diol (IV) by condensation with diethyl malonate derivative (III) by means of Na in MeOH. By heating compound (IV) with phosphorus oxychloride (POCl3), 4,6-dichloro-5-(2-methoxyphenoxy)-2-pyridin-4-yl)pyrimidine (V) is obtained, which in turn is oxidized with peracetic acid in refluxing acetonitrile to afford N-oxide derivative (VI). Condensation of (VI) with 5-isopropylpyridine-2-sulfonamide potassium (VII) furnishes 5-isopropylpyridine-2-sulfonic acid 6-chloro-5-(2-methoxyphenoxy)-2-(1-oxy-pyridin-4-yl)-pyrimidin-4-yl amide (VIII), which is then dissolved in dimethoxyethane and subjected to reaction with Na in hot ethylene glycol (IX) to provide N-[6-(2-hydroxyethoxy)-5-(2-methoxyphenoxy)-2-(1-oxy-pyridin-4-yl)-pyrimidin-4-yl]-5-isopropylpyridine-2-sulfonamide (X). Refluxing of (X) with trimethylsilylcyanide and Et3N in acetonitrile yields cyano derivative (XI), which is then converted into the tetrazole derivative (XII) by reaction with sodium azide and NH4Cl in DMF at 70 C. Finally, the disodium salt of tezosentan is obtained by treatment of (XII) with Na/MeOH in THF. refEP 0799209; JP 1998509182; WO 9619459

…………………………………..

SYNTHESIS PROCEDURE as in EP0979822A1

Examples

1360 ml of formamide were added to 136 g (437 mmol) of 5-(2-methoxy-phenoxy)-2-pyridine-4-yl-pyrimidine-4,6-diole. Then, at a temperature of 0°C, 11.7 ml (219 mmol) of concentrated sulfuric acid and thereafter 36.5 g (130 mmol) of iron(II)sulfate heptahydrate were added to the suspension. After that, 89 ml (874 mmol) of 30% hydrogen peroxide were added dropwise within 1 hr at a temperature of 0°C to 5°C. The viscous yellow-brownish suspension was stirred at 0°C for 1.5 hr. Subsequently, a solution of 83 g (437 mmol) of sodium pyrosulfite in 680 ml of de-ionized water was added dropwise to the reaction mixture within 30 min. at 0°C to 5°C and the reaction mixture was stirred at 0°C to 5°C for 30 min. The suspension was then filtered under reduced pressure. The filtrate was first washed with 1750 ml of de-ionized water and thereafter with 700 ml of ethanol. Then the solid was dried at 80°C, 2000 Pa for 16 hr. There were obtained 132.4 g (91% of theory) of 4-[4,6-dihydroxy-5-(2-methoxy-phenoxy)-pyrimidine-2-yl]-pyridine-2-carboxylic acid amide with a HPLC purity of 91.4% (w/w).
Preparation of starting material:
- a) 53.1 g of 4-cyano-pyridine (98%) are added all at once to a solution of 1.15 g of sodium in 200 ml of abs. MeOH. After 6 hr 29.5 g of NH₄Cl are added while stirring vigorously. The mixture is stirred at room temperature overnight. 600 ml of ether are added thereto, whereupon the precipitate is filtered off under suction and thereafter dried at 50°C under reduced pressure. There is thus obtained 4-amidino-pyridine hydrochloride (decomposition point 245-247°C).
- b) 112.9 g of diethyl (2-methoxyphenoxy)malonate are added dropwise within 30 min. to a solution of 27.60 g of sodium in 400 ml of MeOH. Thereafter, 74.86 g of the amidine hydrochloride obtained in a) are added all at once. The mixture is stirred at room temperature overnight and evaporated at 50°C under reduced pressure. The residue is treated with 500 ml of ether and filtered off under suction. The filter cake is dissolved in 1000 ml of H₂O and treated little by little with 50 ml of CH₃COOH. The precipitate is filtered off under suction, washed with 400 ml of H₂O and dried at 80°C under reduced pressure. There is thus obtained 5-(2-methoxy-phenoxy)-2-(pyridine-4-yl)-pyrimidine-4,6-diole (or tautomer), melting point above 250°C.

Example 2

Within 20 min. 61 ml (633 mmol) of POCl₃ were added dropwise to 34 ml (200 mmol) of diisopropyl ethylamine at 5°C to 10°C followed by stirring at 5°C to 10°C for 15 min. Then 23.5 g (66 mmol) of 4-[4,6-dihydroxy-5-(2-methoxy-phenoxy)-pyrimidine-2-yl]-pyridine-2-carboxylic acid amide were added in four portions under cooling followed by stirring at 90°C for 25 hr. The reaction mixture was cooled down to 20°C and transferred to a new flask together with 50 ml of dichloromethane. Volatile components (i.e. excess of POCl₃) was removed by evaporation from 20°C to 70°C followed by re-distillation with 100 ml of toluene. After adding 250 ml of dichloromethane to the residue (88 g of a black oil) the solution was heated to 35°C to 40°C and 80 ml of de-ionized water were added dropwise within 30 min. whereby the pH was kept constant by the subsequent addition of 28% NaOH solution (60 ml) within 5 to 6 hr. The mixture was stirred at 35°C to 40°C for 30 min. followed by removal of dichloromethane by distillation. The resulting suspension was allowed to cool down to 20°C and was stirred for additional 2 hr. The solid was filtered off under suction, washed with 500 ml of water and dried at 70°C, 2000 Pa for 16 hr. There were obtained 21.3 g (86% of theory) of 4-[4,6-dichloro-5-(2-methoxy-phenoxy)-pyrimidine-2-yl]-pyridine-2-carbonitrile with a HPLC purity of 94.3% (w/w).

8.95 g (24 mmol) of 4-[4,6-dichloro-5-(2-methoxy-phenoxy)-pyrimidine-2-yl]-pyridine-2-carbonitrile were suspended in 100 ml of acetone. At a temperature of 20°C, 5.04 g (25 mmol) of 5-isopropyl-pyridine-2-sulfonamide, 1 ml of de-ionized water, 10.6 g (77 mmol) of potassium carbonate and 135 mg (1.2 mmol) 1,4-diazobicyclo[2.2.2]octane were added. The mixture was stirred at 40°C for 20 hr. Thereafter, another 240 mg (1.2 mmol) of 5-isopropyl-pyridine-2-sulfonamide and 80 mg (0.7 mmol) of 1,4-diazobicyclo[2.2.2]octane were added. The reaction mixture was stirred for 24 hr at 40°C followed by cooling to 20°C. Then 50 ml of de-ionized water and 45 ml of 3 N aqueous hydrochloric acid were added slowly until pH = 1. The acetone was removed by distillation and the resulting suspension was stirred at 20°C for 1.5 hr. The solid was filtered off under suction, washed first with 100 ml of de-ionized water and thereafter with 50 ml of t-butylmethylether. Then the solid was dried at 70°C, 2000 Pa for 20 hr. There were obtained 13.2 g (102% of theory) of 5-isopropyl-pyridine-2-sulfonic acid [6-chloro-2-(2-cyano-pyridine-4-yl)-5-(2-methoxy-phenoxy)-pyrimidine-4-yl]-amide with a HPLC purity of 87.8% (w/w).

122 g (233 mmol) of 5-isopropyl-pyridine-2-sulfonic acid [6-chloro-2-(2-cyano-pyridine-4-yl)-5-(2-methoxy-phenoxy)-pyrimidine-4-yl]-amide was suspended in 450 ml of N,N-dimethyl formamide and the mixture was cooled down to 15°C. At this temperature, 35 ml of hydrazine hydrate were added dropwise within 1 hr. The resulting solution was stirred at 15°C to 20°C for 16 hr and thereafter diluted with 600 ml of de-ionized water. Then 50 ml of glacial acetic acid were added dropwise at 0°C to 5°C until pH = 5.5. 600 g of ice were added and the suspension was stirred for 1 hr. The solid was filtered off under suction, washed with 3000 ml of water and dried at 40°C, 2000 Pa for 24 hr. There were obtained 126 g (97% of theory) of 5-isopropyl-pyridine-2-sulfonic acid [6-chloro-2-[2-(hydrazino-imino-methyl)-pyridine-4-yl]-5-(2-methoxy-phenoxy)-pyrimidine-4-yl]-amide with a HPLC purity of 91.8% (w/w).

20 g (35 mmol) of 5-isopropyl-pyridine-2-sulfonic acid [6-chloro-2-[2-(hydrazino-imino-methyl)-pyridine-4-yl]-5-(2-methoxy-phenoxy)-pyrimidine-4-yl]-amide were added to 160 ml of N,N-dimethyl formamide. The solution was kept at 15°C to 20°C and 23 ml of 6 N aqueous hydrochloric acid were added, followed by addition of a solution containing 4.8 g (7 mmol) of sodium nitrite in 20 ml de-ionized water within 10 min. The mixture was stirred at 20°C for 1 hr, then 140 ml of de-ionized water were added and the suspension was stirred at 0°C for 1 hr. The solid was filtered, firstly washed with 80 ml of de-ionized water and thereafter with 80 ml of t-butylmethylether. Then the solid was dried at 70°C and 2000 Pa for 16 hr. The crude product (23.4 g) was taken up with 117 ml of tetrahydrofuran for 1 hr. After filtration at 0°C the crystallized product was washed with 25 ml of t-butylmethylether and was then dried at 70°C, 2000 Pa for 16 hr. There were obtained 17.3 g (84% of theory) of 5-isopropyl-pyridine-2-sulfonic acid [6-chloro-5-(2-methoxy-phenoxy)-2-[2-(1H-tetrazole-5-yl)-pyridine-4-yl]-pyrimidine-4-yl]-amide with a HPLC purity of 91.1% (w/w).

6.2 g of sodium hydroxide were added to 15 g (26 mmol) of 5-isopropyl-pyridine-2-sulfonic acid [6-chloro-5-(2-methoxy-phenoxy)-2-[2-(1H-tetrazole-5-yl)-pyridine-4-yl]-pyrimidine-4-yl]-amid and 75 ml of ethylene glycol. The mixture was heated to 85°C for 5 hr. Then 55 ml of de-ionized water were added and thereafter 55 ml of 3 N hydrochloric acid were added dropwise. The mixture was allowed to cool down to 20°C and was stirred for 1 hr. The solid was filtered off and dried at 70°C, 2000 Pa for 18 hr. There were obtained 16.2 g (103%) of 5-isopropyl-pyridine-2-sulfonic acid 16-(2-hydroxy-ethoxy)-5-(2-methoxy-phenoxy)-2-[2-(1H-tetrazole-5-yl)-pyridine-4-yl]-pyrimidine-4-yl]-amide with a HPLC purity of 92% (w/w). 80 ml of dioxane and 80 ml of ethanol were added to this solid. At a temperature of 60°C, gaseous ammonia was introduced into the liquid until pH = 9 to 10. The resulting suspension was allowed to cool down to 20°C and was stirred at 20°C for 20 hr and thereafter at 0°C for 2.5 hr. Then the solid was filtered off and dried at 70°C, 2000 Pa for 18 hr. There were obtained 14.2 g of mono ammonium salt with a HPLC purity of 96.2% (w/w). The solid was heated (reflux) in 70 ml of methanol, cooled down slowly to 20°C and stirred at 20°C for 19 hr and thereafter at 0°C for 2 hr. Then the solid was filtered off and dried at 70°C, 2000 Pa for 19 hr. There were obtained 11.5 g (66% of theory) of 5-isopropyl-pyridine-2-sulfonic acid [6-(2-hydroxy-ethoxy)-5-(2-methoxy-phenoxy)-2-[2-(1H-tetrazole-5-yl)-pyridine-4-yl]-pyrimidine-4-yl]-amide sodium salt (1:2) with a HPLC purity of 98.6% (w/w).

Reaction of 2-chloro-5-ispropylpyridine (VII) with thiourea (A) in aqueous HCl gives 5-isopropyl- pyridine-2-thiol (VIII), which is chlorinated with chlorine in acetic acid to yield 5-isopropylpyridine-2-sulfochloride (IX). This compound is converted into 5-isopropylpyridine-2-sulfonamide potassium salt (X).

…………………………

synthesis

WO1996019459A1

. Example 1

a) 200 ml of dimethoxyethane and 1 10.9 g of 4-[4-(4-tert- butyl-phenyl-sulphonylamino)-6-chloro-5-(2-methoxy-phenoxy)- pyrimidin-2-yl]-pyridine 1 -oxide are added all at once to a solution of 23.80 g of sodium in 660 ml of ethylene glycol. The solution is heated at 90°C for 20 hours while stirring, thereafter cooled, poured into 2500 ml of H2O and thereafter treated with CH3COOH to pH 5. The mixture is extracted three times with EtOAc, the organic phase is washed with H2O, dried with Na2Sθ4 and evaporated under reduced pressure. The residue is recrystall- ized from CH3CN and thereafter twice from a mixture of acetone and CH3CN. There is thus obtained 4-[4-(4-tert-butyl-phenyl- sulphonylamino)-6-(2-hydroxy-ethoxy)-5-(2-methoxy-phenoxy)- pyrimidin-2-yl]-pyridine 1 -oxide.

Preparation of the starting material:

b) 53.1 g of 4-cyano-pyridine (98%) are added all at once to a solution of 1.15 g of sodium in 200 ml of abs. MeOH. After

6 hours 29.5 g of NH₄CI are added while stirring vigorously. The mixture is stirred at room temperature overnight. 600 ml of ether are added thereto, whereupon the precipitate is filtered off under suction and thereafter dried at 50°C under reduced pressure. There is thus obtained 4-amidino-pyridine hydro- chloride (decomposition point 245-247°C).

c) 1 12.9 g of diethyl (2-methoxyphenoxy)malonate are added dropwise within 30 minutes to a solution of 27.60 g of sodium in 400 ml of MeOH. Thereafter, 74.86 g of the amidine hydro- chloride obtained in b) are added all at once. The mixture is stirred at room temperature overnight and evaporated at 50°C under reduced pressure. The residue is treated with 500 ml of ether and filtered off under suction. The filter cake is dissolved in 1000 ml of H2O and treated little by little with 50 ml of CH3COOH. The precipitate is filtered off under suction, washed with 400 ml of H2O and dried at 80°C under reduced pressure. There is thus obtained 5-(2-methoxy-phenoxy)-2-(pyridin-4-yl)- pyrimidine-4,6-diol (or tautomer), melting point above 250°C.

d) A suspension of 1 54.6 g of 5-(2-methoxy-phenoxy)-2- (pyridin-4-yl)-pyrimidine-4,6-diol (or tautomer) in 280 ml of POCI3 is heated at 120°C in an oil bath for 24 hours while stirring vigorously. The reaction mixture changes gradually into a dark brown liquid which is evaporated under reduced pressure and thereafter taken up three times with 500 ml of toluene and evaporated. The residue is dissolved in 1000 ml of CH2CI2, treated with ice and H2O and thereafter adjusted with 3N NaOH until the aqueous phase has pH 8. The organic phase is separated and the aqueous phase is extracted twice with CH2CI2. The combined CH2CI2 extracts are dried with MgSθ4, evaporated to half of the volume, treated with 1000 ml of acetone and the CH2CI2 remaining is distilled off at normal pressure. After standing in a refrigerator for 2 hours the crystals are filtered off under suction and dried at 50°C overnight. There is thus obtained 4,6-dichloro-5-(2-methoxy-phenoxy)-2-pyridin-4-yl)- pyrimidine, melting point 1 78-1 80°C.

e) A solution of 1 7.4 g of 4,6-dichloro-5-(2-methoxy- phenoxy)-2-pyridin-4-yl)-pyrimidine in 100 ml of CH3CN is boiled at reflux for 3 hours with 1 5 ml of a 32% peracetic acid solution, thereafter cooled and stored in a refrigerator overnight. The crystals are filtered off under suction and dried at 50°C under reduced pressure. There is thus obtained 4-[4,6-dichloro- 5-(2-methoxy-phenoxy)-pyrimidin-2-yl]-pyridine 1 -oxide, melting point 189-1 90°C.

f) A solution of 36.4 g of 4-[4,6-dichloro-5-(2-methoxy- phenoxy)-pyrimidin-2-yl]-pyridine 1 -oxide and 52.8 g of p-tert- butylphenyl-sulphonamide potassium in 1 50 ml of abs. DMF is stirred at room temperature for 24 hours. Thereafter, it is poured into a mixture of 1 500 ml of H2O and 1000 ml of ether while stirring mechanically, whereby a precipitate forms. The suspension is adjusted to pH 5 with CH3COOH, suction filtered, the crystals are washed with cold water and thereafter with ether and dried at 50°C. There is thus obtained 4-[4-(4-tert- butyl-phenylsulphonylamino)-6-chloro-5-(2-methoxy-phenoxy)- pyrimidin-2-yl]-pyridine 1 -oxide as a colourless material of melting point 247-249°C.

Example 2

A solution of 78.45 g of 4-[4-(4-tert-butyl-phenyl- sulphonylamino)-6-(2-hydroxy-ethoxy)-5-(2-methoxy-phenoxy)- pyrimidin-2-yl]-pyridine 1 -oxide, 122.5 g of trimethylsilyl cyanide, 127.8 g of triethylamine and 1200 ml of CH3CN is boiled at reflux for 20 hours and thereafter evaporated under reduced pressure. The oily residue is taken up in 1000 ml of EtOAc and the solution is washed with CH3COOH:H2θ 9:1 and then with H2O. The EtOAc extracts are dried with Na2SO4. After evaporation of the solvent the residue is taken up in a mixture of CH3CN and CF3COOH (20:1 ), whereby a crystalline precipitate separates. There is thus obtained 4-tert-butyl-N-[2-(2-cyano-pyridin-4- yl)-6-(2-hydroxy-ethoxy)-5-(2-methoxy-phenoxy)-pyrimidin-4- yl]-benzenesulphonamide of melting point 176-1 79°C.

Example 3 for analogy only compd is different

A suspension of 50.0 g of 4-tert-butyl-N-[2-(2-cyano- pyridin-4-yl)-6-(2-hydroxy-ethoxy)-5-(2-methoxy-phenoxy)- pyrimidin-4-yl]-benzenesulphonamide, 46.33 g of NH4CI and 56.47 g of NaN3 in 1600 ml of DMF is heated to 70°C for 24 hours while stirring vigorously. The majority of the solvent is distilled off under reduced pressure, the residue is dissolved in H2O, the solution is extracted four times at pH 6.5 with ether, thereafter treated with CH3COOH to pH = 4.5 and extracted with EtOAc. After working up there is obtained a residue which is treated with ether and filtered off under suction therefrom. There is thus obtained 4-tert-butyl-N-[6-(2-hydroxy-ethoxy)-5-(2- methoxy-phenoxy)-2-(2-1 H-tetrazol-5-yl-pyridin-4-yl)- pyrimidin-4-yl]-benzenesulphonamide, melting point 225-227°C.

Example 30 final product

In analogy to Example 3, from 5-isopropyl-pyridine-2- sulphonic acid 2-(2-cyano-pyridin-4-yl)-6-(2-hydroxy-ethoxy)- 5-(2-methoxy-phenoxy)-pyrimidin-4-ylamide there is obtained 5-isopropyl-pyridine-2-sulphonic acid 6-(2-hydroxy-ethoxy)-5- (2-methoxy-phenoxy)-2-(2-1 H-tetrazol-5-yl-pyridin-4-yl)- pyrimidin-4-ylamide (tezosantan free base) as a white substance of melting point 1 98- 200°C from acetonitrile.

The corresponding disodium salt (tezosantan di sodium salt) is obtained as a white powder from this product using sodium methylate in analogy to Example 5

Example 5 for analogy only, compd is different

A solution of 47.8 g of 2-[6-(4-tert-butyl-phenylsulphonyl- amino)-5-(2-methoxy-phenoxy)-2-(2-1 H-tetrazol-5-yl-pyridin- 4-yl)-pyrimidin-4-yloxy]-ethyl pyridin-2-ylcarbamate in 500 ml of abs. THF is treated dropwise with a cold solution of 2.8 g of sodium in 50 ml of methanol, whereby there forms gradually a solid precipitate which, after stirring at room temperature for 1 hour, is filtered off under suction, dried under greatly reduced pressure at 35°C for 3 days and thereafter at 50°C for 2 days. There is thus obtained the bis-sodium salt, decomposition point above 250°C.

References

Urbanowicz, W; Sogni, P, Moreau, R, Tazi, K A, Barriere, E, Poirel, O, Martin, A, Guimont, M C, Cazals-Hatem, D, Lebrec, D (2004). “Tezosentan, an endothelin receptor antagonist, limits liver injury in endotoxin challenged cirrhotic rats”. Gut (BMJ Publishing Group Ltd & British Society of Gastroenterology) 53 (12): 1844–1849. doi:10.1136/gut.2003.036517. PMC 1774327. PMID 15542526.
“Tezosentan does not appear to improve symptoms for patients with acute heart failure”. Medical Studies/Trials. news-medical.net. 7 Nov 2007. Retrieved 2007-11-24.

3 EP0979822A1

4 US2003/100507 A1

5 Drugs Fut 2003,28(8),754

6 WO 1996019459……

7 EP 0897914

8 WO 2011163085

9 WO 2004082637

10 WO 2002074034

11…

15055997

4-8-2004

Discovery, modeling, and human pharmacokinetics of N-(2-acetyl-4,6-dimethylphenyl)-3-(3,4-dimethylisoxazol-5-ylsulfamoyl)thiophene-2-carboxamide (TBC3711), a second generation, ETA selective, and orally bioavailable endothelin antagonist.

Journal of medicinal chemistry

12 ..

10610277

7-1-1999

RO 610612 .

Drugs in R&D

13….


EP1060749	3-27-2003	Aqueous pharmaceutical composition comprising Tezosentan
US6103902	8-16-2000	Carbamoylation process
WO0036918	6-30-2000	METHODS AND COMPOSITIONS FOR TREATMENT OF CELL PROLIFERATIVE DISORDERS METHODS AND COMPOSITIONS FOR TREATMENT OF CELL PROLIFERATIVE DISORDERS
US6063911	5-17-2000	Methods and compositions for treatment of cell proliferative disorders

VORINOSTAT

Uncategorized Comments Off

Jan 242014

Vorinostat

Zolinza, SAHA, suberoylanilide hydroxamic acid, Suberanilohydroxamic acid, N-hydroxy-N’-phenyloctanediamide

US patent 5369108, PDT PATENT

For the treatment of cutaneous manifestations in patients with cutaneous T-cell lymphoma who have progressive, persistent or recurrent disease on or following two systemic therapies. Inhibits histone deacetylase I & 3.

CCRIS 8456
HSDB 7930
M344
N-Hydroxy-N’-phenyloctanediamide
SAHA
SAHA cpd
Suberanilohydroxamic acid
suberoylanilide hydroxamic acid
UNII-58IFB293JI

N-hydroxy-N‘-phenyl-octanediamide
Trade names	Zolinza, 100 MG, CAPSULE, ORAL
	ZOLINZA (VORINOSTAT) [Merck Sharp & Dohme Corp.]
MedlinePlus	a607050
Licence data	US FDA:link
	LAUNCHED 2006 MERCKhttp://www.accessdata.fda.gov/drugsatfda_docs/label/2011/021991s002lbl.pdf
Legal status	℞-only (US)
Routes	Oral
Pharmacokinetic data
Protein binding	71%
Metabolism	Hepatic glucuronidation andoxidation CYP system not involved
Half-life	2 hours
Excretion	Renal (negligible)
Identifiers
CAS number	149647-78-9
ATC code	L01 XX38

Chemical data
Formula	C₁₄H₂₀N₂O₃
Mol. mass	264.32 g/mol

CLINICAL TRIALS..http://clinicaltrials.gov/search/intervention=Vorinostat

Vorinostat (rINN) also known as suberanilohydroxamic acid (suberoyl+anilide+hydroxamic acid abbreviated as SAHA) is a member of a larger class of compounds that inhibit histone deacetylases (HDAC). Histone deacetylase inhibitors (HDI) have a broad spectrum of epigenetic activities.

Vorinostat is marketed under the name Zolinza for the treatment of cutaneous T cell lymphoma (CTCL) when the disease persists, gets worse, or comes back during or after treatment with other medicines.^[1] The compound was developed by Columbia University chemist, Ronald Breslow.

VORINOSTAT

Vorinostat was the first histone deacetylase inhibitor^[2] approved by the U.S. Food and Drug Administration (FDA) for the treatment of CTCL on October 6, 2006. It is manufactured by Patheon, Inc., in Mississauga, Ontario, Canada, for Merck & Co., Inc., White House Station, New Jersey.^[3]

ZOLINZA contains vorinostat, which is described chemically as N-hydroxy-N’-phenyloctanediamide. The empirical formula is C₁₄H₂₀N₂O₃. The molecular weight is 264.32 and the structural formula is:

ZOLINZA® (vorinostat) Structural Formula Illustration

Vorinostat is a white to light orange powder. It is very slightly soluble in water, slightly soluble in ethanol, isopropanol and acetone, freely soluble in dimethyl sulfoxide and insoluble in methylene chloride. It has no chiral centers and is non-hygroscopic. The differential scanning calorimetry ranged from 161.7 (endotherm) to 163.9°C. The pH of saturated water solutions of vorinostat drug substance was 6.6. The pKa of vorinostat was determined to be 9.2.

Each 100 mg ZOLINZA capsule for oral administration contains 100 mg vorinostat and the following inactive ingredients: microcrystalline cellulose, sodium croscarmellose and magnesium stearate. The capsule shell excipients are titanium dioxide, gelatin and sodium lauryl sulfate.

Vorinostat has been shown to bind to the active site of histone deacetylases and act as a chelator for Zinc ions also found in the active site of histone deacetylases ^[4] Vorinostat’s inhibition of histone deacetylases results in the accumulation of acetylated histones and acetylated proteins, including transcription factors crucial for the expression of genes needed to induce cell differentiation. ^[4]
SAHA inhibits class I and class II HDACs at nanomolar concentrations and arrests cell growth in a wide variety of transformed cells in culture at 2.5-5.0 µM. This compound efficiently suppressed MES-SA cell growth at a low dosage (3 µM) already after 24 hours treatment. Decrease of cell survival was even more pronounced after prolonged treatment and reached 9% and 2% after 48 and 72 hours of treatment, respectively. Colony forming capability of MES-SA cells treated with 3 µM vorinostat for 24 and 48 hours was significantly diminished and blocked after 72 hours.

Vorinostat has also been used to treat Sézary syndrome, another type of lymphoma closely related to CTCL.^[5]

A recent study suggested that vorinostat also possesses some activity against recurrent glioblastoma multiforme, resulting in a median overall survival of 5.7 months (compared to 4 – 4.4 months in earlier studies).^[6] Further brain tumor trials are planned in which vorinostat will be combined with other drugs.

Including vorinostat in treatment of advanced non-small-cell lung cancer (NSCLC) showed improved response rates and increased median progression free survival and overall survival (although the survival improvements were not significant at the P=0.05 level).^[7]

It has given encouraging results in a phase II trial for myelodysplastic syndromes in combination with Idarubicin and Cytarabine.^[8]

Vorinostat is an interesting target for scientists interested in eradicating HIV from infected persons.^[9] Vorinostat was recently shown to have both in vitro and in vivo effects against latently HIV infected T-cells.^[10]^[11]

Vorinostat, represented by structural formula (I) and chemically named as N-hydroxy-N’- phenyl-octanediamide or suberoylanilide hydroxamic acid (SAElA), is a member of a larger class of compounds that inhibit histone deacetylases (HDAC). Histone deacetylase inhibitors (HDI) have a broad spectrum of epigenetic activities and vorinostat is marketed, under the brand name Zolinza^®, for the treatment of a type of skin cancer called cutaneous T-cell lymphoma (CTCL). Vorinostat is approved to be used when the disease persists, gets worse, or comes back during or after treatment with other medicines. Vorinostat has also been used to treat Sέzary’s disease and, in addition, possesses some activity against recurrent glioblastoma multiforme.

Vorinostat was first described in US patent 5369108, wherein four different synthetic routes for the preparation of vorinostat are disclosed (Schemes 1 to 4).

The single step process illustrated in Scheme 1 involves coupling of the diacid chloride of suberic acid with aniline and hydiOxylamine hydrochloride. However, the yield of this reaction is only 15-30%.

Scheme 1

The multistep process illustrated in Scheme 2 begins with the monomethyl ester of suberic acid, which undergoes conversion to the corresponding acid chloride. Further coupling with aniline gives the methyl ester of suberanilic acid. Hydrolysis of the ester and further coupling with benzyl protected hydroxylamine gives benzyl protected vorinostat which on deprotection gives vorinostat.

HO. (CH₂J₆ OMe . ,OOMM e

O O

Scheme 2

In addition to the disadvantage of being a five-step process with overall yields reported as 35-65%, this process suffers from further disadvantages such as the use of the expensive monomethyl ester of suberic acid.

Scheme 3

The two step process illustrated in Scheme 3 involves coupling of the diacid chloride of suberic acid with aniline and O-benzyl hydroxylamine and then deprotection. However, the overall yield of this reaction is only 20-35%.

Scheme 4

The process illustrated in Scheme 4 is similar to that illustrated in Scheme 3, with the exception that O-trimethylsilyl hydroxylamine was used instead of O-benzyl hydroxylamine. The overall yield of this reaction is reported as 20-33%.

Another process for the preparation of vorinostat has been reported in J. Med. Chem.,

1995, vol. 38(8), pages 1411-1413. The reported process, illustrated in Scheme 5, begins with the conversion of suberic acid to suberanilic acid by a high temperature melt reaction.

Suberanilic acid is further converted to the corresponding methyl ester using Dowex resin and the methyl ester of suberanilic acid thus formed is converted to vorinostat by treatment with hydroxylamine hydrochloride. However, this process employs high temperatures (190⁰C) in the preparation of vorinostat which adds to the inefficiency and high processing costs on commercial scale. The high temperatures also increase the likelihood of impurities being formed during manufacture and safety concerns. The overall yield reported was a poor 35%.

MeOH, Dowex, 22 hours

Scheme 5

Another process for the preparation of vorinostat has been reported in OPPI Briefs, 2001, vol. 33(4), pages 391-394. The reported process, illustrated in Scheme 6, involves conversion of suberic acid to suberic anhydride, which on treatment with aniline gives suberanilic acid. Coupling of this suberanilic acid with ethyl chloroformate gives a mixed anhydride which upon treatment with hydroxylamine gives vorinostat in an overall yield of 58%. In the first step, there is competition between the formation of suberic anhydride and the linear anhydride and consequently isolation of pure suberic anhydride from the reaction mixture is very difficult. This process step is also hindered by the formation of process impurities and competitive reactions. In the second step, there is formation of dianilide by reaction of two moles of aniline with the linear anhydride. In the third step, suberanilic acid is an inconvenient by-product as the suberanilic acid is converted to a mixed anhydride with ethyl chloroformate, which is highly unstable and is converted back into suberanilic acid. Consequently, it is very difficult to obtain pure vorinostat from the reaction mixture. Although the reported yield was claimed to be 58%, when repeated a yield of only 38% was obtained.

Scheme 6

A further process for the preparation of vorinostat has been reported in J. Med. Chem., 2005, vol. 48(15), pages 5047-5051. The reported process, illustrated in Scheme 7, involves conversion of monomethyl suberate to monomethyl suberanilic acid, followed by coupling with hydroxylamine hydrochloride to afford vorinostat in an overall yield of 79%. However, the process uses the expensive monomethyl ester of suberic acid as starting material.

HOBt, DCC, DMF, RT, 4 hours

Processes for the preparation of vorinostat, and its form 1 crystalline polymorph, have been disclosed in patent applications US 2004/0122101 and WO 2006/127319. However, the disclosed processes, comprising the preparation of vorinostat from suberic acid, are a cumbersome three step process comprising the sequential steps of amidation of suberic acid with aniline, esterification of the mono-amide product with methanol, and finally reaction with hydroxylamine hydrochloride and sodium methoxide to afford vorinostat. This process is not very convenient as it involves elevated temperatures, lengthy reaction times and has a low overall yield of around 23%. In addition, the intermediate products and final product are not very pure and require exhaustive purification steps.

…………………….

VORINOSTAT

http://www.google.com/patents/EP2349985A2

A preferred embodiment of the first aspect of the present invention is illustrated in Scheme

suberic acid subefanilic acid NH₂OHHCl, CDI

suberoylanilide hydroxamic acid (T)

Scheme 8

Optionally, an activating agent can be used in step (a) and/ or step (b) to afford products with high yields and purity. Preferably, the activating agent is selected from cyanuric chloride, cyanuric fluoride, catecholborane, or a mixture thereof. The activating agent is preferably used in combination with the coupling agent. A preferred embodiment of the process according to the first aspect of the present invention comprises the following steps:

(i) taking a mixture of THF, CDI and DCC;

(ii) adding suberic acid; (iii) adding aniline in THF to the solution from step (ii);

(iv) stirring at 25-30°C;

(v) filtering off the solid dicyclohexyl urea formed in the reaction;

(vi) concentrating the filtrate in vacuo;

(vii) adding a solution of KOH in water; (vϋi) filtering off the solid by-product;

(ix) heating the filtrate;

(x) adding aq. HCl;

(xi) isolating suberanilic acid;

(xii) mixing the suberanilic acid and CDI in DMF; (xiii) adding hydroxylamine hydrochloride as solid to the mixture from step (xii);

(xiv) isolating vorinostat from the mixture obtained in step (xiii);

(xv) adding acetonitrile and aq. ammonia to the vorinostat from step (xiv);

(xvi) heating the mixture;

(xvii) cooling the mixture to 20-27°C; and (xvϋi) isolating pure vorinostat from the mixture obtained in step (xvii).

Preferably, by utilising the same organic solvent in steps (a) and (b), pure vorinostat can be obtained without isolation of any synthetic intermediate^).

A preferred embodiment of the second aspect of the present invention is illustrated in Scheme 9.

suberic acid N-hydtoxy-7-carboxy-heptanamide

Example 1

Stage 1 : Conversion of suberic acid to suberanilic acid

A mixture of CDI (0.5eq) and DCC (0.8eq) in THF (15 vol) was stirred for 1 hour at 25- 3O⁰C. Suberic acid (leq) and aniline (leq) in THF (1 vol) was added and the mixture stirred for a further 16-20 hours. The solid by-product was removed by filtration and the filtrate was concentrated in vacuo at 5O⁰C. The solid residue obtained was treated with a solution of KOH (2eq) in water (10 vol) and stirred for 30 minutes at 25-30⁰C and any solid byproduct formed was removed by filtration. The filtrate obtained was heated at 6O⁰C for 3-4 hours and cooled to 20⁰C before addition of an aqueous solution of HCl (17.5%, 3 vol). The mixture was stirred for 30 minutes and the solid filtered, washed with water (2×5 vol) and dried under vacuum at 60-65⁰C. Molar Yield = 60-65% Purity by HPLC = 99.5%

Stage 2: Conversion of suberanilic acid to crude vorinostat The suberanilic acid (leq) obtained in stage 1 was dissolved in DMF (5 vol) and CDI (2eq) was added at 25-3O⁰C and maintained for 30 minutes under stirring. Hydroxylamine hydrochloride (4eq) was added and stirring continued for 30 minutes. Water (25 vol) was then added and the mixture stirred for 2 hours. The precipitated solid was filtered, washed with water (2×5 vol) and dried under vacuum at 50⁰C. Molar Yield = 70-75% Purity by HPLC = 99% Stage 3: Purification of crude vorinostat

Aqueous ammonia (2.5 vol) was added to the crude vorinostat (leq) in acetonitrile (15 vol) at 25-30°C. The mixture was then maintained at 55-60°C for 1 hour before being cooled to 20-25°C and being stirred for a further hour. The resulting solid was filtered, washed with acetonitrile (2×0.5 vol) and dried under vacuum at 45-5O⁰C for 5 hours. Molar Yield = 55-60% Purity by HPLC > 99.8%

Example 2

Stage 1 : Conversion of suberic acid to crude vorinostat

A mixture of CDI (0.5eq) and DCC (0.8eq) in THF (15 vol) was stirred for 1 hour at 25- 30°C. Suberic acid (leq) and hydroxylamine (leq) in THF (1 vol) was added and the mixture stirred for a further 1 hour. Then CDI (0.5eq), DCC (0.8eq) and aniline (leq) were added to the mixture and the mixture was stirred for a further 16-20 hours. The solid byproduct was removed by filtration and the filtrate was concentrated in vacuo at 50°C to obtain crude vorinostat. Molar Yield = 55-60% Purity by HPLC > 95.8%

Stage 2: Purification of crude vorinostat

Aqueous ammonia (2.5 vol) was added to the crude vorinostat (leq) in acetonitrile (15 vol) at 25-3O⁰C. The mixture was then maintained at 55-60⁰C for 1 hour before being cooled to 20-25⁰C and being stirred for a further hour. The resulting solid was filtered, washed with acetonitrile (2×0.5 vol) and dried under vacuum at 45-50⁰C for 5 hours. Molar Yield = 35-40% Purity by HPLC > 99.8%

…………………………………….

SYNTHESIS

/WO2009098515A1

Scheme V. – –

Vorinostat

Suberic acid (l.Oeq) was dissolved in tetrahydrofuran (15vol) and the clear solution was chilled to 0-5°C. Methyl chloro formate (l.leq) and triethylamine (1.1 eq) were added to the solution at the same temperature and the mixture was stirred for 15 minutes. The triethylamine.HCl salt formed was filtered off, then aniline (leq) was added to the reaction mixture at 0-5⁰C and stirring was continued for 15 minutes. Methyl chloroformate (l.leq) and triethylamine (l.leq) were added to the clear solution and stirring was continued for a further 15 minutes at 0-5°C. This chilled reaction mixture was added to a freshly prepared hydroxylamine solution in methanol (*see below) chilled to 0-5°C and stirred for 15 minutes at 0-5°C. The solvent was removed under vacuum at 40°C and the residue obtained was taken in methylene dichloride and the organic solution was washed with water and dried over anhydrous sodium sulfate. Methylene dichloride was removed under vacuum at 40°C and acetonitrile was added to the residue. This mixture was stirred for 15 minutes before the solid was filtered under vacuum and dried under vacuum at 60°C to afford the product as a white solid. Molar yield = 35-41%; HPLC purity = 99.90%.

VORINOSTAT

¹H-NMR (DMSO-d₆): 1.27 (m, 4H, 2 x -CH₂-), 1.53 (m, 4H, 2 x -CH₂-), 1.94 (t, J = 7.3 Hz, 2H, -CH₂-), 2.29 (t, J = 7.4 Hz, 2H, -CH₂-), 7.03 (t, J = 7.35 Hz, IH, aromatic para position), 7.27 (t, J = 7.90 Hz, 2H, aromatic meta position), 7.58 (t, J = 7.65 Hz, 2H, aromatic ortho position), 8.66 (s, IH, -OH, D₂O exchangeable), 9.85 (s, IH, amide -NH-, D₂O exchangeable), 10.33 (s, IH, -NH-OH, D₂O exchangeable).

¹³C-NMR (DMSO-d₆): 25.04 (2C, 2 x -CH₂-), 28.43 (2C, 2 x -CH₂-), 32.24 (1C, -CH₂-), 36.34 (1C, -CH₂-), 119.01 (2C, Ar-C), 122.96 (1C, Ar-C), 128.68 (2C, Ar-C), 139.24 (1C, Ar- C, =CNH-), 169.23 (1C, -CO-), 171.50 (1C, -CO-).

*Preparation of hydroxylamine solution:

Potassium hydroxide (l.leq) was added to methanol (8vol) and the solution was chilled to 0-5°C. Similarly hydroxylamine hydrochloride (l.leq) was added to methanol (8vol) and chilled to 0-5°C. The chilled amine solution was added to the chilled alkali solution and stirred for 15 minutes at 0-5⁰C. The white potassium chloride salt was filtered off and the filtrate was used as such.

……………………………………………………..

POLYMORPHS

US20040122101

The present invention is directed to a Form I polymorph of SAHA characterized by an X-ray diffraction pattern substantially similar to that set forth in FIG. 13A. SAHA Form I is also characterized by an X-ray diffraction pattern including characteristic peaks at about at about 9.0, 9.4, 17.5, 19.4, 20.0, 24.0, 24.4, 24.8, 25.0, 28.0, and 43.3 degrees 2θ. SAHA Form I is further characterized by an X-ray diffraction pattern including characteristic peaks at about 9.0, 9.4, 17.5, 19.4, 20.0, 24.0, 24.4, 24.8, 25.0, 28.0, 43.3 degrees 20, and lacking at least one peak at about <8.7, 10.0-10.2, 13.4-14.0, 15.0-15.2, 17.5-19.0, 20.1-20.3, 21.1-21.3, 22.0-22.22, 22.7-23.0, 25.0-25.5, 26.0-26.2, and 27.4-27.6 degrees 2θ.

………………………………………………………

SPECTRAL DATA AND SYNTHESIS

Journal of Medicinal Chemistry, 2011 , vol. 54, 13 pg. 4694 – 4720

http://pubs.acs.org/doi/full/10.1021/jm2003552

http://pubs.acs.org/doi/suppl/10.1021/jm2003552/suppl_file/jm2003552_si_001.pdf

for structures see above link

Suberoylanilide hydroxamic acid (26, SAHA, vorinostat).

Suberic acid monomethyl ester (23) (15.09 g, 80.2 mmol) and DMF (0.10 mL) in anhydrous
DCM (300 mL) was added SOCl2 (34.6 mL, 0.481 mol), and the reaction mixture was refluxed for 3
h. The mixture was then concentrated. Toluene (300 mL) was added to the residue and evaporated
to afford crude acid chloride 24. Crude 24 was dissolved in DCM (240 mL), and followed by
addition of aniline (7.3 mL, 80.2 mmol) and Et3N (16.9 mL, 0.120 mol). The reaction mixture was
stirred for 90 min at room temp. The course of reaction was monitored by TLC (30% EtOAc in
hexanes) and LC–MS. DCM was removed, and ethyl acetate (500 mL) was added to dissolve the
residue. The organic layer was washed with aqueous NaHCO3 (500 mL × 2), 1 N HCl (400 mL × 2),
water, dried (Na2SO4), and evaporated to dryness under reduced pressure. The residue was purified
by vacuum liquid chromatography (silica, 20% EtOAc in hexanes) to afford compound 25as white crystalline solids (20.15 g, 96 %). NaOMe in MeOH solution (5.4 M, 106 mL, 0.573 mol) was added to a solution of compound 25 (10.05 g, 38.2 mmol) and NH2OH·HCl (26.54 g, 0.382 mol) in

dry MeOH (375 mL). The reaction mixture was stirred for 40 min at room temp. The reaction was
quenched by adding of 1 N HCl to pH 7–8. MeOH was removed under reduced pressure and water
(1 L) was added to the residue. The precipitated solid was filtered and washed with water (300 mL)
and EtOAc (150 mL) to afford crude 26 which was further purified by recrystallization. MeOH (200
mL) was added to crude 26 (5 g) and warmed to dissolve all solids. The MeOH solution was filtered,

and deionized water (400 mL) was added to the filtrate, the resulting solution was placed at 4 oC
overnight. Crystals obtained were filtered and washed with deionized water (100 mL) to afford pure
26 (vorinostat, SAHA) as off-white crystals. Overall yield: 80–85% from compound 23. Compound
26,

LC–MS m/z 265.1 ([M + H]+).

1H NMR (DMSO-d6)  10.35 (1H, s), 9.86 (1H, s), 8.68 (1H, s),
7.58 (2H, d, J = 7.6 Hz), 7.28 (2H, t, J = 7.5 Hz), 7.02 (1H, t, J = 7.4 Hz), 2.29 (2H, t, J = 7.4 Hz),
1.94 (2H, t, J = 7.4 Hz), 1.57 (2H, m), 1.49 (2H, m), 1.33 – 1.20 (2H, m); 13C NMR (DMSO-d6) 
171.2, 169.1, 139.3, 128.6, 122.9, 119.0, 36.3, 32.2, 28.4, 28.3, 25.0. Anal. (C10H20N2O3) C, H, N.

………………………………………………………….

References

“ZOLINZA, Merck’s Investigational Medicine for Advanced Cutaneous T-Cell Lymphoma (CTCL), To Receive Priority Review from U.S. Food and Drug Administration” (Press release). Merck & Co. June 7, 2006. Retrieved 2006-10-06.
HDAC Inhibitors Base (vorinostat)
“FDA Approves New Drug for Skin Cancer, Zolinza” (Press release). Food and Drug Administration. October 6, 2006. Retrieved 2006-10-06.
Richon, Victoria. “Cancer biology: mechanism of antitumour action of vorinostat (suberoylanilide hydroxamic acid), a novel histone deacetylase inhibitor”. British Journal of Cancer. Retrieved 3 May 2012.
Cuneo A, Castoldi. “Mycosis fungoides/Sezary’s syndrome”. Retrieved 2008-02-15.
“Vorinostat shows anti-cancer activity in recurrent gliomas” (Press release). Mayo Clinic. June 3, 2007. Retrieved 2007-06-03.
http://www.rtmagazine.com/reuters_article.asp?id=20091209clin013.html Dec 2009. URL dead Jan 2012
“Zolinza, Idarubicin, Cytarabine Combination Yields High Response Rates In MDS Patients (ASH 2011)”.
“Study of the Effect of Vorinostat on HIV RNA Expression in the Resting CD4+ T Cells of HIV+ Pts on Stable ART”. ClinicalTrials.gov. 2011-03-21.
Archin NM, Espeseth A, Parker D, Cheema M, Hazuda D, Margolis DM (2009). “Expression of latent HIV induced by the potent HDAC inhibitor suberoylanilide hydroxamic acid.”. AIDS Res Hum Retroviruses 25 (2): 207–12. doi:10.1089/aid.2008.0191. PMC 2853863. PMID 19239360.
Contreras X, Schweneker M, Chen CS, McCune JM, Deeks SG, Martin J et al. (2009). “Suberoylanilide hydroxamic acid reactivates HIV from latently infected cells.”. J Biol Chem 284 (11): 6782–9.doi:10.1074/jbc.M807898200. PMC 2652322. PMID 19136668.
Vorinostat bound to proteins in the PDB
J. Med. Chem.,1995, vol. 38(8), pages 1411-1413.
A new simple and high-yield synthesis of suberoylanilide hydroxamic acid and its inhibitory effect alone or in combination with retinoids on proliferation of human prostate cancer cells
J Med Chem 2005, 48(15): 5047
A new facile and expeditious synthesis of N-hydroxy-N’-phenyloctanediamide, a potent inducer of terminal cytodifferentiation
Org Prep Proced Int 2001, 33(4): 391
US patent 5369108, PDT PATENT
WO2007/22408………
WO 1993007148
CN 102344392

United States	7456219	APPROVAL 2006-11-14	EXPIRY 2026-11-14
United States	6087367	1994-10-04	2011-10-04
Canada	2120619	2006-11-21	2012-10-05

Patent	Patent Expiry	pat use code
7399787	Feb 9, 2025	U-892
7456219	Mar 11, 2027
7652069	Mar 4, 2023
7732490	Mar 4, 2023	U-892
7851509	Feb 21, 2024	U-892
8067472	Mar 4, 2023	U-892
8093295	May 16, 2026
8101663	Mar 4, 2023	U-892
RE38506	Nov 29, 2013

U 892 =TREATMENT OF CUTANEOUS MANIFESTATIONS IN PATIENTS WTIH CUTANEOUS T-CELL LYMPHOMA (CTCL)

Exclusivity Code	Exclusivity_Date
ODE	Oct 6, 2013

WO2009098515A1 *

Feb 6, 2009

Aug 13, 2009

Generics Uk Ltd

Novel process for the preparation of vorinostat

Marks, P.A., Breslow, R. Dimethyl sulfoxide to vorinostat: Development of this histone deacetylase inhibitor as an anticancer drug. Nat Biotech 25(1) 84-90 (2007). DOI: 10.1038/nbt1272
Takashi Kumagai, et al. Histone deacetylase inhibitor, suberoylanilide hydroxamic acid (Vorinostat, SAHA) profoundly inhibits the growth of human pancreatic cancer cells. International Journal of Cancer. 2007 Aug 1;121(3):656-65. DOI: 10.1002/ijc.22558
Hrzenjak A, et al. Histone deacetylase inhibitor vorinostat suppresses the growth of uterine sarcomas in vitro and in vivo. Mol Cancer. 2010 Mar 4;9:49. DOI: 10.1186/1476-4598-9-49

………………………………………………………………………………………

US7148257	Aug 26, 2003	Dec 12, 2006	Merck Hdac Research, Llc	Methods of treating mesothelioma with suberoylanilide hydroxamic acid
US7375137	Mar 28, 2006	May 20, 2008	Merck Hdac Research, Llc	Methods of treating cancer with HDAC inhibitors
US7399787	Jul 9, 2003	Jul 15, 2008	Merck Hdac Research, Llc	Methods of treating cancer with HDAC inhibitors
US7456219	Jun 19, 2003	Nov 25, 2008	Merck Hdac Research, Llc	Polymorphs of suberoylanilide hydroxamic acid
US7652069	Oct 30, 2007	Jan 26, 2010	Merck Hdac Research, Llc	Polymorphs of suberoylanilide hydroxamic acid
US7732490	Sep 11, 2007	Jun 8, 2010	Merck Hdac Research, Llc	Methods of treating cancer
US7847122	Mar 18, 2008	Dec 7, 2010	Merck Hdac Research, Llc	Polymorphs of suberoylanilide hydroxamic acid
US7851509	Mar 18, 2008	Dec 14, 2010	Merck Hdac Research, Llc	Polymorphs of suberoylanilide hydroxamic acid
US7879865	Nov 18, 2005	Feb 1, 2011	Sloan-Kettering Institute For Cancer Research	Treatment of cancer of the brain using histone deacetylase inhibitors
US7998957	Feb 6, 2008	Aug 16, 2011	Lixte Biotechnology, Inc.	Oxabicycloheptanes and oxabicylcoheptenes, their preparation and use
US8058268	Jul 29, 2009	Nov 15, 2011	Lixte Biotechnology, Inc.	Neuroprotective agents for the prevention and treatment of neurodegenerative diseases
US8067472	Apr 23, 2010	Nov 29, 2011	Merck Hdac Research, Llc	Methods of treating Hodgkin’s and non-Hodgkin’s lymphoma
US8088951	Nov 30, 2007	Jan 3, 2012	Massachusetts Institute Of Technology	Epigenetic mechanisms re-establish access to long-term memory after neuronal loss
US8093295	May 16, 2006	Jan 10, 2012	Merck Sharp & Dohme Corp.	Formulations of suberoylanilide hydroxamic acid and methods for producing the same
US8101663	Dec 7, 2009	Jan 24, 2012	Merck Hdac Research, Llc	Polymorphs of suberoylanilide hydroxamic acid
US8143445	Oct 1, 2008	Mar 27, 2012	Lixte Biotechnology, Inc.	HDAC inhibitors
US8227473	Jul 17, 2009	Jul 24, 2012	Lixte Biotechnology, Inc.	Oxabicycloheptanes and oxabicycloheptenes, their preparation and use
US8288440 *	Jan 13, 2010	Oct 16, 2012	Merck Sharp & Dohme Corp.	Formulations of suberoylanilide hydroxamic acid and methods for producing same
US8329719	Aug 1, 2011	Dec 11, 2012	Lixte Biotechnology, Inc.	Neuroprotective agents for the prevention and treatment of neurodegenerative diseases
US8426444	Jun 30, 2011	Apr 23, 2013	Lixte Biotechnology, Inc.	Oxabicycloheptanes and oxabicycloheptenes, their preparation and use
US8450372 *	Jan 13, 2010	May 28, 2013	Merck Sharp & Dohme Corp.	Formulations of suberoylanilide hydroxamic acid and methods for producing same
US8455688	Mar 21, 2012	Jun 4, 2013	Lixte Biotechnology, Inc.	HDAC inhibitors
US8541458	Jun 11, 2012	Sep 24, 2013	Lixte Biotechnology, Inc.	Oxabicycloheptanes and oxabicycloheptenes, their preparation and use
US8563615	Nov 1, 2010	Oct 22, 2013	Massachusetts Institute Of Technology	Use of CI-994 and dinaline for the treatment of memory/cognition and anxiety disorders
US20100112046 *	Jan 13, 2010	May 6, 2010	Jeannie Chow Wong	Formulations of suberoylanilide hydroxamic acid and methods for producing same
US20100113829 *	Jan 13, 2010	May 6, 2010	Cote Aaron S	Formulations of suberoylanilide hydroxamic acid and methods for producing same
US20100119596 *	Jan 13, 2010	May 13, 2010	Jeannie Chow Wong	Formulations of suberoylanilide hydroxamic acid and methods for producing same
US20110263712 *	Oct 14, 2009	Oct 27, 2011	Generics (Uk) Limited	Process for the preparation of vorinostat
US20110313044 *	Jun 16, 2011	Dec 22, 2011	Urquima S.A.	Polymorphs of Suberoylanilide Hydroxamic Acid
EP2079304A1 *	Sep 24, 2007	Jul 22, 2009	Merck & Co., Inc.	Amine base salts of saha and polymorphs thereof
EP2229941A1 *	May 16, 2006	Sep 22, 2010	Merck Sharp & Dohme Corp.	Formulations of suberoylanilide hydroxamic acid and methods for producing same
EP2292221A2 *	May 16, 2006	Mar 9, 2011	Merck Sharp & Dohme Corp.	Formulations of suberoylanilide hydroxamic acid and methods for producing same
WO2006127319A2 *	May 16, 2006	Nov 30, 2006	Merck & Co Inc	Formulations of suberoylanilide hydroxamic acid and methods for producing same
WO2006127321A2 *	May 16, 2006	Nov 30, 2006	Merck & Co Inc	Formulations of suberoylanilide hydroxamic acid and methods for producing same
WO2008039421A2 *	Sep 24, 2007	Apr 3, 2008	Arlene E Mckeown	Pharmaceutical compositions of hdac inhibitors and chelatable metal compounds, and metal-hdac inhibitor chelate complexes
WO2008042146A1 *	Sep 24, 2007	Apr 10, 2008	Arlene E Mckeown	Amine base salts of saha and polymorphs thereof
WO2008097654A1 *	Feb 8, 2008	Aug 14, 2008	Nancie M Archin	Methods of using saha for treating hiv infection
WO2009020565A1 *	Aug 1, 2008	Feb 12, 2009	Lixte Biotechnology Inc	Use of phosphatases to treat neuroblastomas and medulloblastomas
WO2010061220A2 *	Nov 25, 2009	Jun 3, 2010	Generics [Uk] Limited	Novel processes and pure polymorphs

EXTRAS

MS-275 (Entinostat); CI-994 (Tacedinaline); BML-210; M344; MGCD0103 (Mocetinostat); PXD101 (Belinostat); LBH-589 (Panobinostat); Tubastatin A; Scriptaid; NSC 3852; NCH 51; HNHA; BML-281; CBHA; Salermide ; Pimelic Diphenylamide; ITF2357 (Givinostat); PCI-24781; APHA Compound 8; Droxinostat; SB939.

Older Entries

All About Drugs

AUTHOR OF THIS BLOG

VARDENAFIL

Lodenafil Carbonate … an Erectile Dysfunction Drug in Phase III

References

Prediction of Drug Degradation Pathways leading to Structural Alerts for Potential Genotoxic Impurities

Prediction of Drug Degradation Pathways leading to Structural Alerts for Potential Genotoxic Impurities

Dasantafil for Treatment of Erectile Dysfunction

Risk Assessment of Genotoxic Impurities in Marketed Compounds Administered over a Short-Term Duration: Applications to Oncology Products and Implications for Impurity Control Limits

Risk Assessment of Genotoxic Impurities in Marketed Compounds Administered over a Short-Term Duration: Applications to Oncology Products and Implications for Impurity Control Limits

DOLUTEGRAVIR

DOXOFYLLINE

14-chapter 4.pdf – Shodhganga

AVANAFIL

Tezosentan disodium for pulmonary hypertension

VORINOSTAT

References

Follow All About Drugs

WO2010011812A1 *	Jul 23, 2009	Jan 28, 2010	Smithkline Beecham Corporation	Chemical compounds
WO2010011819A1 *	Jul 23, 2009	Jan 28, 2010	Smithkline Beecham Corporation	Chemical compounds