Carbotegravir, Dolutegravir, New Patent, WO 2016113372, Lek Pharmaceutical and Chemical Co DD

PATENTS Comments Off

Jul 252016

WO 2016113372

Carbotegravir, New Patent, WO 2016113372, Lek Pharmaceutical and Chemical Co DD

LEK PHARMACEUTICALS D.D. [SI/SI]; Verovskova 57 1526 Ljubljana (SI)

MARAS, Nenad; (SI).
SELIC, Lovro; (SI).
CUSAK, Anja; (SI)

ViiV Healthcare is developing cabotegravir (first disclosed in WO2006088173), which in July 2016, was reported to be in phase 2 clinical development.

WO-2016113372

Process for preparing integrase inhibitors such as dolutegravir and cabotegravir and their analogs, useful for treating viral infections eg HIV infection. Also claims a process for preparing intermediates of dolutegravir and cabotegravir.

(4R, 12aS)-N-[(2,4-Difluorophenyl)methyl]-3 ,4,6,8, 12, 12a-hexahydro-7-hydroxy-4-methyl-6,8-dioxo-2H-pyrido[1 ‘,2’:4,5]pyrazino[2, 1-b][1 ,3]oxazine-9-carboxamide (Formula A):

Formula A

known by the INN name dolutegravir, is a new efficient antiviral agent from the group of HIV integrase inhibitors which is used in combination with some other antiviral agents for treatment of HIV infections, such as AIDS. The compound, which belongs to condensed polycyclic pyridines and was first disclosed in WO2006/1 16764, is marketed.

Another compound disclosed in WO2006/1 16764 is (3S, 1 1 aR)-N-[(2,4-difluorophenyl)methyl]-6-hydroxy-3-methyl-5,7-dioxo-2,3,5,7, 1 1 ,1 1 a-hexahydro[1 ,3]oxazolo[3,2-a]pyrido[1 ,2-d]pyrazine-8-carboxamide (Formula

Formula C

known by the INN name cabotegravir.

The complex structures of dolutegravir and cabotegravir present a synthetic challenge. The first description of the synthesis in WO2006/1 16764 shows a 16-steps synthesis (see Scheme A), which is industrially impractical due to its length and low overall yield.

Scheme A

WO 2010/068253 and WO 2006/1 16764 describe an alternative synthesis. The 1 1 -step synthesis, shown in Scheme B1 and Scheme B2, is based on bromination of the 9-position for further introduction of the carboxylic group. The synthesis relies on the use of expensive palladium catalysts and toxic selenium compounds. Furthermore, some variations of these approaches involve pyrone intermediates in several steps. In some cases pyrones are liquids which can complicate purification, while further reactions form complex mixtures.

doiutegravir

Scheme B2

In further alternative syntheses, acetoacetates were used as starting materials. Such an approach is challenging in terms of introducing the hydroxy group in the 7-position. The variation in Scheme C1 , described in WO2012/018065, starts from 4-benzyloxyacetoacetate. The procedure requires 9 steps, but use expensive reagents like palladium catalysts. Moreover, there is described a possibility of formation a co-crystal between an intermediate and hydroquinone, wherein however the additional step may diminish yields and make the process longer and time consuming.

Scheme C1

The variation in Scheme C2, described in WO2012/018065, starts from 4-chloroacetoacetate. The process is not optimal because of problems in steps which include pyrones and because of problems with conversion of 7-chloro to 7-hydroxy group which includes a disadvantageous use of silanolates with low yield (25%).

Scheme C2

The variation in Scheme C3, described in WO201 1/1 19566, starts from unsubstituted acetoacetate. For the introduction of the 7-hydroxy group, bromination is used and substitution of bromo with hydroxy is performed by a use of silanolates. The substitution of the bromine is achieved in a 43% yield.

Scheme C3

The variation in Scheme C4, described in WO201 1/1 19566, starts from 4-methoxyacetoacetate aiming at preparing dolutegravir or cabotegravir. The process uses lithium bases to affect a difficult to control selective monohydrolysis of a diester.

The object of the present invention is to provide short, simple, cost-effective, environmentally friendly and industrially suitable processes for beneficially providing dolutegravir and analogues thereof and cabotegravir and analogues thereof, in particular dolutegravir.

Scheme 1

According to an embodiment of the process of the invention the building block 3-aminobutanol can suitably be substituted with other aminoalcohols to give dolutegravir analogues. For example, using (S)-alaninol gives cabotegravir as the final product. Similarly, using amines other than 2,4-difluorobenzylamine in the amidation step results in the synthesis of other dolutegravir analogues.

According to the another preferred embodiment cabotegravir or a pharmaceutically acceptable salt thereof is prepared by the analogue process, which comprises providing a compound of formula (5c)

converting the compound of formula (5c) to a compound of formula (6c)

by carrying out a chlorination reaction, and converting the compound of formula (6c) to cabotegravir and/or a pharmaceutically acceptable salt thereof.

The compound of formula (5c) can preferably be provided by converting a compound of formula (3) to a compound of formula (4c)

Scheme 2

1. ) EtOCOCI, Et₃N / Me₂CO

2. ) 2,4-difiuorobenzylamine

Scheme 3

Analogous compound of formula 7c is a useful intermediate in the synthesis of cabotegravir. Scheme 3a

Scheme 4

Examples

The following examples are merely illustrative of the present invention and they should not be considered as limiting the scope of the invention in any way. The examples and modifications or other equivalents thereof will become apparent to those versed in the art in the light of the present entire disclosure. Particularly, all Examples related to the preparation of dolutegravir and intermediates thereof can be used by the analogy for the preparation of cabotegravir and intermediates thereof.

Example 1 :

Methyl acetoacetate (1 , 25.22 g) and dimethylformamide dimethyl acetal (DMFDMA, 35 mL) was heated at 50-55°C for 2 h, then methanol (60 mL), aminoacetaldehyde dimethyl acetal (24 mL) and acetic acid (4 mL) was added an the mixture was heated under reflux for one hour, then concentrated. MTBE (100 mL) was added and the mixture was kept at 5 °C overnight to crystallize. Upon filtration 46 g (92%) of product 2 was recovered.

¹H NMR (DMSO-d₆): δ 2.31 (s, 3H), 3.30 (s, 6H), 3.49 (m, 2H), 3.61 (s, 3H), 4.43 (m, 1 H), 8.02 (d, 1 H), 10.8 (bs, 1 H). ¹³C NMR (DMSO-d₆): δ 30.52, 35.48, 50.53, 54.23, 98.99, 102.47, 160.70, 166.92, 197.21 .

Example 2:

Compound 2 (5.00 g) was dissolved in 2-propanol, dimethyl oxalate (7.02 g) was added and heated to 40 °C. Sodium methylate (25% in methanol; 20 mL) was slowly (10 min) added, the mixture was then heated to 50-55 °C and stirred at that temperature for 2-2.5 h. The mixture was cooled to ambient temperature, then sodium hydroxide solution (1 M, 65 mL) was added to the mixture and stirred for another 2 h, followed by addition of concentrated hydrochloric acid (1 1 mL) and stirred for another 2 h. The precipitate was filtered and dried to give 8.08 g (NMR assay 47%; 65% yield) of compound 3.

¹H NMR (DMSO-d₆): δ 2.50 (m, 2H), 3.30 (s. 6H), 4.49 (m, 1 H), 7.06 (s, 1 H); 8.70 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 55.23, 55.37, 102.34, 1 15.47, 120.24, 145.17, 162.71 , 165.22, 178.55.

Example 3:

Compound 2 (158.37 g) was dissolved in methanol (548 mL), followed by the addition of dimethyl oxalate (202.2 g). While keeping the temperature below 30°C, potassium ferf-butoxide (192.1 g) was added and reaction mixture was heated at 50 °C overnight. The suspension was then filtered and the filter cake washed with methanol. The filtrate was concentrated (approximately to 680 mL), then water (680 mL) was added, followed by addition of lithium hydroxide hydrate (143.7 g) while keeping the temperature below 40 °C. The suspension was then stirred at ambient temperature overnight and filtered. To the obtained filtrate, concentrated hydrochloric acid (339 mL) was added while keeping the temperature below 30 °C. The suspension was aged for 2 h and filtered to give 4 as a white powder (95.6 g, NMR assay 100%; 52% yield).

Example 4:

Compound 2 (5.00 g) was dissolved in 2-propanol, dimethyl oxalate (7.02 g) was added and heated to 40 °C. Sodium methylate (25% in methanol; 15 mL) was slowly (10 min) added then the mixture was heated to 50-55 °C and stirred at that temperature for 72 h. The mixture was concentrated and components were separated by flash column chromatography (ethyl acetate/methanol 9:1 to 6:4). Early fractions gave compound 22 upon concentration, late fractions gave compound 23.

Compound 22: ¹H NMR (DMSO-d₆): δ 2.49 (m, 2H), 3.28 (s, 6H), 3.73 (s, 3H), 3.85 (s, 3H), 4.41 (m, 1 H), 4.50 (m, 1 H), 6.65 (s, 1 H), 8.36 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 51.63, 53.36, 54.25, 55.47, 102.71 , 1 18.24, 123.60, 140.81 , 150.21 , 162.44, 164.49, 173.43.

Compound 23: ¹H NMR (DMSO-d₆): δ 2.49 (m, 2H), 3.26 (s, 6H); 3.70 (s, 3H); 4.33 (d, 1 H); 4.60 (m, 1 H), 6.19 (s, 1 H), 8.12 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 50.03, 51.34, 54.59, 54.85, 102.91 , 1 16.04, 1 18.19, 148.32, 152.12, 163.46, 165.24, 174.99

Example 5:

Compound 3 (5.5 g; assay 53%) was suspended in acetonitrile, acetic acid (6 mL) and methanesulfonic acid (2.5 mL) were added followed by the heating of mixture to 70 °C for 4 h. The suspension was filtered and filtrate cooled to ambient temperature. Triethylamine (6.6 mL) and (R)-3-amino-butan-1 -ol (1.24 mL) was added followed by heating the mixture at reflux temperature for 20-24 h. The mixture was filtered, filtrate concentrated and 1 M HCI (100 mL) was added, followed by extraction with dichloromethane (3 x 50 mL). Combined organic fractions were concentrated, 2-propanol was added (10 mL) and suspension was stirred at 70-80 °C for 10 min, left to cool to ambient temperature then filtered to give 2.19 g of compound 4 (73%).

¹H NMR (DMSO-de): δ 1.31 (d, 3H), 1.52 (m, 1 H), 1 .97 (m, 1 H), 3.89 (m, 1 H), 4.01 (m, 1 H), 4.46 (m, 1 H), 4.64 (m, 1 H), 4.78 (m, 1 H), 5.50 (m, 1 H), 7.29 (s, 1 H), 8.88 (s, 1 H), 15.83 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 15.22, 29.14, 45.26, 51.13, 62.09, 76.03, 1 16.31 , 1 18.79, 140.53, 146.79, 155.36, 165.24, 178.75.

Example 6:

Compound 3 (14.55 g; assay 49%) was suspended in acetonitrile (125 mL), acetic acid (15 mL) and methanesulfonic acid (6.25 mL) were added followed by the heating of mixture to 70 °C for 4 h. The suspension was filtered and filtrate cooled to ambient temperature. Triethylamine (16.5 mL) and (S)-2-aminopropanol (2.45 mL) was added followed by heating the mixture at reflux temperature for 24 h. The insoluble product was filtered, washed with 2-propanol (20 mL) and dried to give (3S, 1 1 aR)-3-methyl-5,7-dioxo-2,3,5,7, 1 1 ,1 1 a-hexahydrooxazolo[3,2-a]pyrido[1 ,2-d]pyrazine-8-carboxylic acid (5.2 g, 75%).

¹H NMR (DMSO-d₆): δ 1.31 (d, J = 6.3 Hz, 3H), 3.65 (dd, J = 8.6, 6.8 Hz, 1 H), 4.13 (dd, J = 1 1.7, 10.3 Hz, 1 H), 4.28 (m, 1 H), 4.39 (dd, J = 8.6, 6.8 Hz, 1 H), 4.92 (dd, J = 12.3, 4.2 Hz, 1 H), 5.45 (dd, J = 10.2, 4.1 Hz, 1 H), 7.16 (s, 1 H), 8.84 (s, 1 H), 15.74 (s, 1 H).

Example 7:

Compound 4 (0.63 g) was dissolved in dichloromethane (15 mL), cooled to 5°C, then triethylamine (0.31 mL) was added, followed by ethyl chloroformate (0.26 mL), followed by slow (30 min) addition of 2,4-difluorobenzylamine. The mixture was then stirred at ambient temperature for 24 h. Water (10 mL) was added, organic phase was separated and washed with 1 M HCI (15 mL) and water (15 mL), concentrated and treated with 2-propanol to give the product 5 in a quantitative yield.

¹H NMR (CDCI₃): δ 1.39 (d, 3H), 1.52 (s, 1 H), 2.19 (m, 1 H), 4.00 (m, 2H), 4.16 (m, 1 H), 4.31 (m, 1 H), 4.62 (d, 2H), 5.00 (m, 1 H), 5.27 (m, 1 H), 6.80 (m 2H), 7.33 (m, 2H), 8.49 (s, 1 H), 10.48 (s, 1 H). ¹³C NMR (CDCI₃): 15.50, 29.22, 36.43, 45.19, 51.83, 62.79, 103.71 , 103.91 , 1 1 1 .0, 1 1 1 .18, 120.59, 123.04, 130.40, 137.41 , 144.58, 156.27, 163. 87, 177.83.

Example 8:

To a suspension of 4 (2.84 g, 10 mmol) in a mixture of triethylamine (2.24 mL, 16 mmol) and acetone (50 mL) stirring on an ice bath was added ethyl chloroformate (1 .20 mL, 12 mmol). After stirring for 10 min, 2,4-difluorobenzylamine (1.21 mL, 10 mmol) was added and the mixture left stirring at room temperature for 1 h. The product was isolated by slowly diluting the reaction mixture with water (50 mL), partial concentration, filtration, washing with water (2 50 mL) and drying. There was obtained 5 as a white powder (3.48 g, 86%): mp 181.0-184.7 °C. ¹H NMR (DMSO-d₆): δ 1.29 (d, J = 7.0 Hz, 3H), 1 .56 (dd, J = 13.9, 2.0 Hz, 1 H), 1 .93-2.06 (m, 1 H), 3.90 (ddd, J = 1 1.6, 5.0, 2.1 Hz, 1 H), 3.98 (td, J = 12.0, 2.2 Hz, 1 H), 4.45 (dd, J = 13.6, 6.6 Hz, 1 H), 4.72 (dd, J = 13.6, 3.8 Hz, 1 H), 4.74-4.81 (m, 1 H), 5.44 (dd, J = 6.6, 3.8 Hz, 1 H), 8.93 (s, 1 H), 15.14 (s, 1 H). ¹³C NMR (DMSO-d₆): δ 15.78, 29.13, 44.89, 52.88, 61 .63, 75.61 , 1 13.54, 128.49, 136.42, 145.64, 154.62, 164.58, 174.58

Example 9:

To a suspension of 4 (1 1.36 g, 40 mmol) in acetonitrile (80 mL) stirring at room temperature was added TCCA (9.29 g, 38 mmol) and DABCO (0.23 g, 5 mol%). After stirring at room temperature for 1 h, the reaction was quenched with a mixture of DMSO (5.26 mL) and water (1.33 mL). The insoluble cyanuric acid was removed by filtration and the filtrate evaporated under reduced pressure to give viscous oil. This was triturated in methanol (20 mL) to induce crystallization. The product was filtered, washed with cold methanol (10 mL) and dried to give 7 as a yellowish powder (5.13 g, 41 %): mp 191 .3-198.7 °C.

Example 10:

Attempted chlorination of 23: Compound 23 (0.54g) was suspended in acetonitrile (10 mL) and trichlorocyanuric acid (0.44 g) was added and the solution was stirred at ambient temperature overnight. Precipitate was filtered. Only traces of a product corresponding to the compound 26 could be detected in the reaction mixture by LC-MS analysis. Conversion did not improve with time.

Example 11 :

Attempted chlorination of 3: Compound 3 (0.30 g) was suspended in acetonitrile (5 mL) and trichlorocyanuric acid (0.13 g) was added. The suspension was stirred at ambient temperature overnight. Only traces of a product corresponding to the compound 24 could be detected in the reaction mixture by LC-MS analysis.

Example 12:

9 10

Trichloroisocyanuric acid (0.23 g) was added in a single portion to a stirred solution of the diethyl 1 -(2,2-dimethoxyethyl)-4-oxo-1 ,4-dihydropyridine-2,5-dicarboxylate (9, 0.66 g) in dry acetonitrile (4 mL) at room temperature. The resulting suspension was stirred at room temperature for ca. 24 h. The reaction mixture was diluted with dichloromethane and filtrated. The filtrate was then concentrated in vacuo to afford crude oil (0.86 g). Purification by flash chromatography (eluting ethyl acetate/cyclohexane) furnished diethyl 3-chloro-1 -(2,2-dimethoxyethyl)-4-oxo-1 ,4-dihydropyridine-2,5-dicarboxylate, 10 as a yellow semi-solid (0.38 g). ¹H NMR (CDCI₃): δ 1.28 (t, J=7A Hz, 3H), 1 .37 (t, J=7.2 Hz, 3H), 3.35 (s, 6H), 3.89 (d, J=5.0 Hz, 2H), 4.27 (q, J=l A Hz, 2H), 4.43 (q, J=l A Hz, 2H), 4.48 (t, J=4.9 Hz, 1 H), 8.15 (s, 1 H). ¹³C NMR (CDCI₃): δ 13.83, 14.13, 55.82, 57.09, 61.41 , 63.72, 102.52, 1 17.35, 126.90, 140.22, 146.92, 160.67, 164.13, 168.95.

Example 13:

Diethyl 1 -(2,2-dimethoxyethyl)-4-oxo-1 ,4-dihydropyridine-2,5-dicarboxylate (9, 0.64 g) was dissolved in anhydrous acetonitrile (6 mL) and treated sequentially with acetic acid (560 μί) and methanesulfonic acid (40 μί). The resulting mixture was heated to 62 °C and stirred for 4 h and more methanesulfonic acid (40 μΙ_) was added. After additional 2 h, more methanesulfonic acid (80 μΙ_) was added. This was repeated after additional 2 h, when more methanesulfonic acid (80 μΙ_) was added. The reaction mixture was stirred additional 17 h at 62 °C then was treated with a mixture of (R)-3-aminobutanol (0.22 g), triethylamine (0.5 mL) and acetonitrile (0.7 mL). The reaction mixture was stirred additional 22 h at 62 °C and then concentrated in vacuo. The crude material was partitioned between dichloromethane and 1 M HCI solution (15 mL). The combined organic phases were dried (Na₂S0₄), filtered and concentrated in vacuo to afford the crude (4R, 12aS)-ethyl 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-carboxylate (11 ) as a brownish oil (0.61 g).

¹H NMR (CD₃OD): δ 8.44 (s, 1 H), 7.16 (m, 1 H), 5.48 (t, J=4.8 Hz, 1 H), 4.86 (m, 1 H), 4.49 (dd, J=13.6, 4.0 Hz, 1 H), 4.30-4.25 (m, 3H), 4.09 (dt, J=12.1 , 2.3 Hz, 1 H), 3.96 (ddd, J=1 1.7, 5.0, 2.1 Hz, 1 H), 2.18-2.10 (m, 1 H), 1.60-1 .56 (m, 1 H) 1 .39 (d, J=7A Hz, 3H), 1.33 (t, J=7A Hz, 3H). ¹³C NMR (CDCI₃): δ 8.45, 14.08, 15.39, 29.17, 45.04, 45.72, 51 .56, 60.86, 62.61 , 76.33, 1 19.54, 123.72, 136.96, 145.67, 156.26, 163.68, 175.43

Example 14:

¹⁰

Diethyl 3-chloro-1 -(2,2-dimethoxyethyl)-4-oxo-1 ,4-dihydropyridine-2,5-dicarboxylate (10, 1.23 g) was dissolved in 85% formic acid (25 mL) at room temperature. The mixture was warmed to 40 °C and stirred for 23 h. The reaction mixture was concentrated in vacuo, and then partitioned between dichloromethane and aqueous NaHC0₃ solution. The combined organic phases were dried (Na₂S0₄), filtered and concentrated in vacuo to afford brownish oil (0.49 g). The crude oil was dissolved in anhydrous toluene (5 mL) and treated sequentially with (R)-3-aminobutanol (0.19 g), methanol (0.2 mL) and acetic acid (96 μί). The resulting mixture was heated to 90 °C and stirred for 20 h. The reaction mixture was cooled to room temperature and then partitioned between dichloromethane and aqueous NaHC0₃ solution. The combined organic phases were dried (Na₂S0₄), filtered and concentrated in vacuo to afford the crude (4R,12aS)-Ethyl 7-chloro-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-carboxylate (12) as a brownish oil (0.24 g).

Example 15:

To a solution of 4 (5.68 g, 20 mmol) in dichloromethane (50 mL) stirring in an ice bath was added triethylamine (5.6 mL, 40 mmol), followed by ethyl chloroformate (2.61 mL, 26 mmol). After 20 min, ethanol (50 mL) was added. The mixture was then left stirring 24 h at room temperature and concentrated under reduced pressure. The residue was triturated in acetone (80 mL). The insoluble salt (triethylamine hydrochloride) was removed by filtration. The filtrate was evaporated under reduced pressure to give 11 as an amorphous solid in a quantitative yield (6.1 g).

Example 16:

To a stirring solution of 11 (0.94 g, 3.0 mmol) in acetonitrile (8 mL) heated at 40 °C was added TCCA in portions during 1 h (0.44 g, 1 .8 mmol). After an additional 1 h, the reaction mixture was diluted with a solution of NaHS0₃ (0.60 g) in water (60 mL), extracted with dichloromethane (50 mL) and the extract evaporated under reduced pressure to give a crude product which was purified by flash chromatography (CH₂CI₂ : MeOH, from 98 : 2 to 80 : 20) to give 12 (0.45 g, 44%).

¹H NMR (CDCI₃): δ 1.37 (t, J = 7.1 Hz, 3H), 1.38 (d, J = 7.0 Hz, 3H), 1 .56 (dq, J = 13.9, 2.2 Hz, 1 H), 2.21 (m, 1 H), 3.99 (d, J = 2.3 Hz, 1 H), 4.00 (t, J = 1.8 Hz, 1 H), 4.10 (dd, J = 13.2, 6.6 Hz, 1 H), 4.37-4.27 (m, 3H), 4.98 (m, 1 H), 5.35 (dd, J = 6.6, 3.8 Hz, 1 H), 8.07 (s, 1 H).

¹³C NMR (CDCI₃): δ 14.20, 16.09, 29.34, 44.87, 53.73, 61.49, 62.29, 76.01 , 1 16.22, 133.1 1 , 134.18, 144.52, 155.48, 163.88, 169.98.

Example 17:

To a mixture of 7 (3.89 g, 12.2 mmol) in methanol (12 mL) was added sodium methylate (22.3 mL, 97.6 mmol). The reaction mixture was stirred for 24 h at 30 °C and then quenched with a slow addition of 3M hydrochloric acid (35 mL) while stirring in an ice bath. The mixture was concentrated under reduced pressure to remove most of the methanol, then extracted with dichloromethane (2 30 mL), the combined extracts washed with water (30 mL) and evaporated under reduced pressure. Methanol (20 mL) was added to the obtained amorphous residue and removed under reduced pressure to yield the solid 8 (3.69 g, 98%).

¹H NMR (CDCI₃): δ 15.04 (s, 1 H), 8.42 (s, 1 H), 5.29 (dd, J=5.6, 3.9 Hz, 1 H), 5.01 -4.96 (m, 1 H), 4.42 (dd, J=13.6, 3.6 Hz, 1 H), 4.25 (dd, J=13.6, 6.0 Hz, 1 H), 4.05 (s, 3H), 4.00-3.97 (m, 2H), 2.21 -2-14 (m, 1 H), 1.53 (dd, J=14.1 , 1.9 Hz, 1 H), 1.36 (d, J=7 Hz, 3H). ¹³C NMR (CDCI₃): δ 176.35, 165.94, 155.03, 153.70, 143.08, 130.90, 1 15.94, 76.05, 62.65, 61.45, 53.86, 44.96, 29.43, 16.06.

Example 18:

To a suspension of 7 (2.55 g, 8.0 mmol) in a mixture of triethylamine (1 .46 mL, 10.4 mmol) and acetone (32 mL) stirring on an ice bath was added ethyl chloroformate (0.88 mL, 8.8 mmol). After stirring for 10 min, 2,4-difluorobenzylamine (1.07 mL, 8.8 mmol) was added and the mixture left stirring at room temperature for 1 h. The product was isolated by slowly diluting the reaction mixture with water (40 mL), filtration, washing with water (2 30 mL) and drying. There was obtained 2.91 g of 6 as a white powder (83%).

¹H NMR (CDCI₃): δ 1.30 (d, J = 7.0 Hz, 3H), 1 .49 (dd, J = 14.0, 2.2 Hz, 1 H), 2.14 (ddd, J = 14.6, 1 1.1 , 6.4 Hz, 1 H), 3.89-3.95 (m, 2H), 4.09-4.15 (m, 1 H), 4.26 (dd, J = 13.4, 3.8 Hz, 1 H), 4.55 (d, J = 5.8 Hz, 2H), 4.89-4.98 (m, 1 H), 5.18 (dd, J = 6.2, 3.8 Hz, 1 H), 6.68-6.79 (m, 2H), 7.23-7.31 (m, 1 H), 8.41 (s, 1 H), 10.24 (t, J = 5.8 Hz, 1 H). ¹³C NMR (CDCI₃): δ 16.09, 26.95, 29.30, 36.79, 45.1 1 , 45.28, 53.86, 62.47, 75.93, 103.87 (t, J = 25.4 Hz), 1 1 1 .21 (dd, J = 21 .0, 3.4 Hz), 1 17.32, 130.58 (dd, J = 9.3, 5.8 Hz), 133.40, 143.54, 155.34, 163.16, 163.25, 163.35, 172.88.

Example 19:

To a suspension of 5 (1 .67 g, 4 mmol) in acetonitrile (20 mL) was added DABCO (23 mg, 5 mol%) and TCCA (0.62 g, 2.52 mmol). The mixture was stirred 18 h at 40 °C protected from light and then quenched with a mixture of DMSO (0.48 mL) and water (0.12 mL). The insoluble cyanuric acid was removed by filtration and washed with acetonitrile (5 mL). The filtrate was evaporated under reduced pressure to give viscous oil that was crystallized from a mixture of methanol (6 mL) and water (3 mL), by slowly cooling the solution from 60 °C to room

temperature. The product 6 was filtered, washed with cold methanol (5 mL) and dried to give an off-white powder (1.07 g, 61 %).

¹H NMR (CDCI₃): δ 1.30 (d, J = 7.0 Hz, 3H), 1 .49 (dd, J = 14.0, 2.2 Hz, 1 H), 2.14 (ddd, J = 14.6, 1 1.1 , 6.4 Hz, 1 H), 3.89-3.95 (m, 2H), 4.09-4.15 (m, 1 H), 4.26 (dd, J = 13.4, 3.8 Hz, 1 H), 4.55 (d, J = 5.8 Hz, 2H), 4.89-4.98 (m, 1 H), 5.18 (dd, J = 6.2, 3.8 Hz, 1 H), 6.68-6.79 (m, 2H), 7.23-7.31 (m, 1 H), 8.41 (s, 1 H), 10.24 (t, J = 5.8 Hz, 1 H). ¹³C NMR (CDCI₃): δ 16.09, 26.95, 29.30, 36.79, 45.1 1 , 45.28, 53.86, 62.47, 75.93, 103.87 (t, J = 25.4 Hz), 1 1 1 .21 (dd, J = 21.0, 3.4 Hz), 1 17.32, 130.58 (dd, J = 9.3, 5.8 Hz), 133.40, 143.54, 155.34, 163.16, 163.25, 163.35, 172.88.

Example 20:

To a suspension of 6 (0.44 g) in anhydrous methanol (1 mL) was added a 25% methanolic solution of sodium methylate (1 .14 mL) and the mixture stirred for 4 h at 40 °C. The reaction was quenched with acetic acid (0.4 mL), diluted with water (8 mL), extracted with 2-methyltetrahydrofuran (12 mL), the extract washed with 1 M NaOH(aq) (8 mL), water (8 mL) and evaporated under reduced pressure. To the oily residue was added methanol (8 mL) and evaporated under reduced pressure to give 27 as a white solid (0.38 g, 88%).

Example 21 :

The suspension of (4R, 12aS)-7-chloro-N-(2,4-difluorobenzyl)-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 (6, 0.44 g) and solid sodium hydroxide (0.20 g) in absolute ethanol (2 mL) was stirred at room temperature for 24 h. The reaction was quenched with 2M H₂S0₄ (1 .18 mL) and left stirring for 2 h at room temperature. The reaction mixture was filtered through fitted funnel rinsing with water (2 x 2 mL). The obtained white precipitate (0.38 g) was suspended in THF-water (1 :1 , 4.5 mL) and stirred at room temperature for ca. 2 h. The reaction mixture was filtered through fitted funnel rinsing with water (2 ^χ 1 mL) and dried in vacuo at 40°C to afford pure dolutegravir as a white solid (0.33 g, HPLC purity: 99.38%).

¹H NMR (DMSO-d₆): δ 12.51 (s, 1 H), 10.36 (t, J=5.9 Hz, 1 H), 8.50 (s, 1 H), 7.41-7.36 (m, 1 H), 7.26-7.21 (m, 1 H), 7.07-7.03 (m, 1 H), 5.45 (dd, J=5.4, 4.3 Hz, 1 H), 4.81 -4.76 (m, 1 H), 4.59-4.53 (m, 3H), 4.36 (dd, J=13.8, 5.8 Hz, 1 H), 4.05-4.00 (m, 1 H), 3.91-3.88 (m, 1 H), 2.05-1 .97 (m, 1 H), 1.55-1.52 (m, 1 H), 1 .33 (d, J=7.1 Hz, 3H). ¹³C NMR (DMSO-d₆): δ 170.27, 163.68, 162.29, 161 .78 (dd), 159.82 (dd), 154.61 , 140.64, 130.74 (d), 130.67 (d), 122.37 (d), 1 16.73, 1 15.38, 1 1 1 .33 (d), 103.80 (t), 62.01 , 51 .16, 44.69, 35.74, 29.13, 15.21.

Example 22:

A suspension of dolutegravir (0.31 g) in methanol (4 mL) was cooled to 0 °C.25% Solution of sodium methoxide in methanol was added to the mixture and the resulting suspension was stirred at 0 °C for 2 h, then at room temperature for 23 h. The reaction mixture was then filtered through fitted funnel rinsing with methanol (3 x 10 mL). The white precipitate was dried overnight at room temperature to afford pure dolutegravir sodium as a white solid (0.26 g, HPLC purity: 99.84%).

¹H NMR (DMSO-d₆): δ 10.70 (t, J=5.8, 1H), 7.89 (s, 1H), 7.37-7.30 (m, 1H), 7.23-7.19 (m, 1H), 7.04-7.01 (m, 1H), 5.17 (m, 1H), 4.81 (t, J=6.4Hz, 1H), 4.51 (d, J=5.5Hz, 2H), 4.32-4.29 (m, 1H), 4.16 (dd, J=14.1, 4.8 Hz, 1H), 3.99-3.94 (m, 1H), 3.82-3.80 (m, 1H), 1.89-1.84 (m, 1H), 1.38 (d, J=12.9 Hz, 1H), 1.24 (d, J=7.0Hz, 3H).¹³C NMR (DMSO-d₆): δ 177.93, 167.12, 166.08, 161.59 (dd), 161.13, 159.63 (dd), 134.26, 130.44 (d), 130.38 (d), 122.90 (d), 114.95, 111.23 (d), 108.78, 103.64 (t), 75.59, 61.95, 53.11, 43.01, 35.32, 29.22, 15.30.

Example 23:

The suspension of 6 (0.44 g) and solid sodium hydroxide (0.20 g) in absolute ethanol (2 mL) was stirred at room temperature for 24 h. The reaction was diluted with absolute ethanol (10 mL) and left stirring for ca. 30 min at room temperature. The reaction mixture was filtered through fitted funnel rinsing with absolute ethanol (3 x 10 mL) and dried in vacuo at room temperature to afford dolutegravir sodium as a pale yellow solid (0.43 g, HPLC purity: 98.80%). ¹H NMR (DMSO-d₆): δ 10.70 (t, J = 5.8 Hz, 1H), 7.89 (s, 1H), 7.37-7.30 (m, 1H), 7.23-7.19 (m, 1H), 7.04-7.01 (m, 1H), 5.17 (m, 1H), 4.81 (t, J = 6.4 Hz, 1H), 4.51 (d, J = 5.5 Hz, 2H), 4.32-4.29 (m, 1H), 4.16 (dd, J= 14.1, 4.8 Hz, 1H), 3.99-3.94 (m, 1H), 3.82-3.80 (m, 1H), 1.89-1.84 (m, 1H), 1.38 (d, J = 12.9 Hz, 1H), 1.24 (d, J = 7.0 Hz, 3H).¹³C NMR (DMSO-d₆): δ 177.93, 167.12, 166.08, 161.59 (dd), 161.13, 159.63 (dd), 134.26, 130.44 (d), 130.38 (d), 122.90 (d), 114.95, 111.23 (d), 108.78, 103.64 (t), 75.59, 61.95, 53.11, 43.01, 35.32, 29.22, 15.30.

Example 24:

The suspension of (4R,12aS)-N-(2,4-difluorobenzyl)-7-methoxy-4-methyl-6,8-dioxo-3,4,6,8,12, 12a-hexahydro-2H-pyrido[1′,2′:4,5]pyrazino[2,1-6][1,3]oxazine-9-carboxamide (27, 0.43 g) and solid sodium hydroxide (0.20 g) in absolute ethanol (2.5 mL) was stirred at room temperature for ca.24 h. The reaction was diluted with mixture of water/ethanol (5 mL, 1:1) and left stirring for ca. 1.5 h at room temperature. The reaction mixture was filtered through fitted funnel rinsing with mixture of water/ethanol (3 x 5 mL, 1:1) and dried in vacuo at room temperature to afford 15 as a pale yellow solid (0.41 g, HPLC purity: 98.87%).

¹H NMR (DMSO-de): δ 10.70 (t, J = 5.8 Hz, 1H), 7.89 (s, 1H), 7.37-7.30 (m, 1H), 7.23-7.19 (m, 1H), 7.04-7.01 (m, 1H), 5.17 (m, 1H), 4.81 (t, J = 6.4 Hz, 1H), 4.51 (d, J = 5.5 Hz, 2H), 4.32-4.29 (m, 1H), 4.16 (dd, J = 14.1, 4.8 Hz, 1H), 3.99-3.94 (m, 1H), 3.82-3.80 (m, 1H), 1.89-1.84 (m, 1H), 1.38 (d, J = 12.9 Hz, 1H), 1.24 (d, J = 7.0 Hz, 3H).¹³C NMR (DMSO-d₆): δ 177.93, 167.12, 166.08, 161.59 (dd), 161.13, 159.63 (dd), 134.26, 130.44 (d), 130.38 (d), 122.90 (d), 114.95, 111.23 (d), 108.78, 103.64 (t), 75.59, 61.95, 53.11, 43.01, 35.32, 29.22, 15.30.

Example 25:

The suspension of {4R, 12aS)-7-chloro-4-methyl-6,8-dioxo-3,4, 6,8, 12,12a-hexahydro-2H-pyrido[1′,2′:4,5]pyrazino[2,1-6][1,3]oxazine-9-carboxylic acid (7, 0.31 g) and solid sodium hydroxide (0.20 g) in absolute ethanol (2.5 mL) was stirred at 50 °C for 3 days. The reaction was quenched with 2M H₂S0₄ (1.2 mL) and left stirring for 7 h at room temperature. The reaction mixture was filtered through fitted funnel rinsing with water (3×5 mL) and ethanol (5 mL) dried in vacuo at 40°C to afford 28 as a pale yellow solid (0.17 g).

¹H NMR (DMSO-d₆): δ 15.37 (s, 1H), 12.76 (s, 1H), 8.66 (s, 1H), 5.51-5.49 (m, 1H), 4.80-4.78 (m, 1H), 4.65 (dd, J=13.8, 3.7 Hz, 1H), 4.43 (dd, J=13.8, 5.9 Hz, 1H), 4.05 (t, J^^.b Hz, 1H), 3.91 (dd, J=11.4, 3.1 Hz, 1H), 2.07-2.00 (m, 1H), 1.56 (d, J=13.8 Hz, 1H), 1.34 (d, J=7.0 Hz, 3H).¹³C NMR (DMSO-de): δ 172.21, 165.39, 161.73, 153.61, 141.11, 118.66, 112.99, 75.95, 62.03, 51.50, 44.90, 29.08, 15.18.

Example 26:

The suspension of (4R,12aS)-N-(2,4-difluorobenzyl)-7-methoxy-4-methyl-6,8-dioxo-3,4,6,8, 12, 12a-hexahydro-2H-pyrido[1 ‘,2’:4,5]pyrazino[2, 1 ,3]oxazine-9-carboxamide (27, 0.88 g) and solid sodium hydroxide (0.24 g) in absolute ethanol (20 mL) was stirred at 30 °C for 1.5 h. The reaction was quenched with 2M H₂S0₄ (1 .5 mL) and left stirring for 3 hours at room temperature. The reaction mixture was filtered through fritted funnel and rinsed with water (3 x 2 mL) and ethanol (4 mL), and dried in vacuo at 40 °C to afford O-ethyl dolutegravir (29) as a pale yellow solid (0.25 g). The filtrate was extracted with ethyl acetate (3 x 5 mL). The combined organic layers were dried over MgS0₄, filtered and concentrated, then dried in vacuo at 40 °C to afford more 29 as a pale yellow solid (0.27 g).

¹H NMR (CDCI₃): δ 10.37 (t, J = 5.8 Hz, 1 H), 8.36 (s, 1 H), 7.37-7.32 (m, 1 H), 6.83-6.77 (m, 2H), 5.19 (dd, J = 5.9, 3.8 Hz, 1 H), 5.04-4.98 (m, 1 H), 4.61 (d, J = 6Hz, 2H), 4.26-4.22 (m, 3H), 4.1 1 (dd, J = 13.4, 5.9 Hz, 1 H), 3.97 (t, J = 2.4 Hz, 1 H), 3.96 (d, J = 2.4 Hz, 1 H), 2.21-2.14 (m, 1 H), 1.51 (dq, J = 14.0, 2.3 Hz, 1 H), 1 .47 (t, J = 7.0 Hz, 3H), 1 .35 (d, J = 7.1 Hz, 3H).

¹³C NMR (CDCI₃): δ 174.78, 164.17, 162.49 (dd), 160.51 (dd), 155.72, 154.08, 142.32, 130.60 (dd), 129.33, 121 .51 (dd), 1 18.67, 1 1 1 .23 (dd), 103.78 (t), 76.15, 69.74, 62.58, 53.42, 44.58, 36.50 (d), 29.44, 16.04, 15.64.

Example 27:

The suspension of (4R, 12aS)-7-(benzyloxy)-4-methyl-3,4, 12,12a-tetrahydro-2H-pyrido[1 ‘,2’:4,5]pyrazino[2, 1-b][1 ,3]oxazine-6,8-dione (30, 0.68 g, prepared according to prior art) and solid sodium hydroxide (0.40 g) in absolute ethanol (5 mL) was stirred at 50 °C for 14 h. The reaction was quenched with formic acid (0.35 mL), water (2 mL) was added and mixture was left stirring for additional 1 h at room temperature. The reaction mixture was extracted with ethyl acetate (3 x 5 mL) and the combined organic layers concentrated to afford a crude oil. Purification by flash chromatography (eluting with CH₂CI₂/methanol) afforded 32 as an orange solid (0.26 g, 52 %).

The above procedure if done at room temperature in same time period, affords 31 as orange oil (0.24 g, 43 %).

Compound 32: ¹H NMR (DMSO-d₆): δ 7.64 (d, J = 7.4 Hz, 1 H), 6.20 (d, J = 7.3 Hz, 1 H), 5.40 (dd, J = 5.1 , 4.2 Hz, 1 H), 4.83-4.78 (m, 1 H), 4.35 (dd, J = 13.6, 3.9 Hz, 1 H), 4.13 (dd, J = 13.6, 5.4 Hz, 1 H), 4.05-4.00 (m, 1 H), 3.90-3.85 (m, 1 H), 2.03-1.95 (m, 1 H), 1.52 (dd, J = 13.9, 1 .9 Hz, 1 H), 1.33 (d, J = 7.1 Hz, 3H). ¹³C NMR (DMSO-d₆): δ 170.96, 163.01 , 153.48, 137.96, 1 16.83, 1 13.52, 76.18, 62.05, 50.39, 44.53, 29.21 , 15.28.

Compound 31 : ¹H NMR (DMSO-d₆): δ 7.67 (d, J = 7.4 Hz, 1 H), 6.28 (d, J = 7.4 Hz, 1 H), 5.29 (dd, J = 5.4, 3.8 Hz, 1 H), 4.82-4.75 (m, 1 H), 4.32 (dd, J = 13.6, 3.6 Hz, 1 H), 4.10 (dd, J = 13.5, 5.6 Hz, 1 H), 4.03-3.93 (m, 3H), 3.85 (ddd, J = 1 1 .6, 5.0, 2.2 Hz, 1 H), 1.97-1 .89 (m, 1 H), 1 .48 (dd, J = 13.8, 2.1 Hz, 1 H), 1.27 (d, J = 7.1 Hz, 3H), 1.26 (d, J = 7.0 Hz, 3H). ¹³C NMR (DMSO-d₆): δ 174.38, 156.1 1 , 150.82, 139.48, 1 16.39, 1 13.52, 75.92, 67.31 , 61 .80, 51 .36, 44.22, 29.29, 15.76, 15.36.

Exa

The transformation of 6 to dolutegravir with sodium hydroxide in ethanol was monitored for the interconversion of intermediates. The suspension of 6 (0.44 g) and solid sodium hydroxide (0.20 g) in ethanol (3.33 ml.) was stirred at 22 °C. Samples of the reaction mixture were taken after 3, 8 and 24 h for UPLC analysis. After 24 h, the reaction mixture was quenched with 2 M H₂S0₄ (5 ml_), and left stirring at room temperature. The reaction mixture was filtered through fritted funnel, the product rinsed with water (30 ml.) and dried in vacuo at 50 °C overnight to afford dolutegravir as a white solid (0.27 g, 64 %).

The results of reaction monitoring:

Time UPLC analysis (area%)

Entry

(h) compound 6 compound 29 dolutegravir

1 3 h 37.50 20.63 39.99

2 8 h 0.78 15.46 80.32

3 24h 0.31 8.56 88.21

Example 29:

The effect of added water and reaction temperature was evaluated by monitoring 4 reactions in parallel. To the suspensions of 27 (0.86 g) in MeOH were added solid sodium hydroxide (0.40 g) or aqueous solution of NaOH (5 M, 2 ml.) (see Table below). The reactions were stirred in parallel at 50 °C or 22 °C. Samples were taken in timely intervals for UPLC analysis.

The results of reaction monitoring demethylation of 27 in MeOH:

Example 30:

The effect of added water and reaction temperature was evaluated by monitoring 4 reactions in parallel. To the suspensions of 6 (0.88 g) in EtOH were added solid sodium hydroxide (0.40 g) or aqueous solution of NaOH (5 M, 2 mL) (see Table below). The reactions were stirred in parallel at 50 °C or 22 °C. Samples were taken in timely intervals for UPLC analysis.

The results of reaction monitoring of the transformations of 6 in ethanol with NaOH:

dol. = dolutegravir

Exa

The effect of added water and reaction temperature was evaluated by monitoring 4 reactions in parallel. To the suspensions of 27 (0.88 g) in EtOH were added solid sodium hydroxide (0.40 g) or aqueous solution of NaOH (5 M, 2ml_) (see Table below). The reactions were stirred in parallel at 50 °C or 22 °C. Samples were taken in timely intervals for UPLC analysis.

The results of reaction monitoring of the transformations of 27 in ethanol with NaOH:

dol. = dolutegravir

Example 32:

Compound 3 (30 g, 1 10 mmol; assay 99%) was suspended in acetonitrile (450 mL), acetic acid (73 mL) and methanesulfonic acid (25 mL) were added. The reaction mixture was stirred 4 h at 70 °C. The clear red solution was cooled to 25 °C. Triethylamine (77 mL) and (S)-2-aminopropanol (17 mL) were added and the mixture was stirred at reflux temperature for 20 h. The reaction mixture was cooled to 25 °C and the insoluble product filtered, washed with 1 M HCI(aq) (60 mL), water (3 * 60 mL) and dried to give 4c (19.49 g, 67%): mp = 313-315 °C; ¹H NMR (DMSO-d₆): δ 1.31 (d, J = 6.3 Hz, 3H), 3.65 (dd, J = 8.6, 6.8 Hz, 1 H), 4.13 (dd, J = 1 1.7, 10.3 Hz, 1 H), 4.28 (m, 1 H), 4.39 (dd, J = 8.6, 6.8 Hz, 1 H), 4.92 (dd, J = 12.3, 4.2 Hz, 1 H), 5.45 (dd, J = 10.2, 4.1 Hz, 1 H), 7.16 (s, 1 H), 8.84 (s, 1 H), 15.74 (s, 1 H); ¹³C NMR (DMSO-d₆) 16.5, 51.6, 52.9, 72.4, 81.6, 1 15.8, 1 18.1 , 141.5, 147.6, 153.4, 165.3, 179.0.

Example 33

Compound 4c (2.78 g) was suspended in dimethylformamide (40 mL), cooled to 0 °C, then triethylamine (3.52 mL) was added, followed by ethyl chloroformate (1 .31 mL). After 10 min there was added 2,4-difluorobenzylamine (1 .57 mL). The mixture was then stirred at 25 °C for 1 h. Water (150 mL) was added and the mixture extracted with dichloromethane (50 mL). The organic phase was separated, washed with water (2 ^χ 50 mL), dried over sodium sulfate and evaporated under reduced pressure. The residue (4.31 g) was treated with boiling 2-propanol (40 mL), the suspension cooled, the product filtered and dried to give the product 5c as a white powder (2.70 g, 69%): 99.80 area% by HPLC at 258 nm; mp = 222-223 °C; MS (ESI) m/z = 390 [MH]⁺; ¹H NMR (DMSO-d₆): δ 1 .30 (d, J = 6.3 Hz, 3H), 3.63 (dd, J = 8.6, 6.8 Hz, 1 H), 4.02 (m, 1 H), 4.26 (m, 1 H), 4.37 (dd, J = 8.6, 6.8 Hz, 1 H), 4.53 (d, J = 6.0 Hz, 2H), 4.84 (dd, J = 12.2, 4.2 Hz, 1 H), 5.40 (dd, J = 12.2, 4.2 Hz, 1 H), 6.91 (s, 1 H), 7.05 (m, 1 H), 7.24 (m, 1 H), 7.38 (m, 1 H), 8.62 (s, 1 H), 10.43 (t, J = 6.0 Hz, 1 H).

To a suspension of 5c (2.70 g, 6.9 mmol) in acetonitrile (32 mL) was added DABCO (39 mg, 5 mol%) and TCCA (1.01 g, 4.3 mmol). The mixture was stirred 20 h at 40 °C protected from light and then quenched with a mixture of DMSO (0.81 mL) and water (0.20 mL). The insoluble cyanuric acid was removed by filtration and washed with acetonitrile (10 mL). The filtrate was evaporated under reduced pressure to give viscous oil that was crystallized from a mixture of methanol (10 mL) and water (5 mL), by slowly cooling the solution from 60 °C to room temperature. The product 6c was filtered, washed with cold methanol (8 mL) and dried to give an off-white powder (1 .20 g, 41 %): mp = 225-227 °C; MS (ESI) m/z = 424 [MH]⁺; ¹H NMR

(DMSO-d₆): δ 1.28 (d, J = 6.3 Hz, 3H), 3.65 (dd, J = 8.6, 6.9 Hz, 1 H), 4.09 (m, 1 H), 4.26 (m, 1 H), 4.35 (dd, J = 8.6, 6.6 Hz, 1 H), 4.54 (d, J = 5.9 Hz, 2H), 4.85 (dd, J = 12.3, 3.8 Hz, 1 H), 5.42 (dd, J = 10.1 , 3.8 Hz, 1 H), 7.06 (m, 1 H), 7.24 (m, 1 H), 7.40 (m, 1 H), 8.67 (s, 1 H), 10.24 (t, J = 6.0 Hz, 1 H).

Example 35

cabotegravir

The suspension of 6c (1.00 g, 2.4 mmol) and sodium hydroxide (0.57 g, 14.2 mmol) in absolute ethanol (7 mL) was stirred at 40 °C for 16 h. The reaction was quenched with 0.5M H₂S0₄ (15 mL), extracted with dichloromethane (20 mL), the extract washed with water (20 mL) and evaporated under reduced pressure. The residue was triturated in MTBE (10 mL), the product filtered, washed with MTBE (10 mL) and dried to give cabotegravir as an off-white solid (0.74 g, 77%): MS (ESI) m/z = 405 [MH]⁺.

Lek, a Sandoz company, opens the first production facility in Slovenia for drug substances for innovative medicines at its Mengeš site

Vojmir Urlep, president of Lek Board of Management

Dr Miro Cerar, the Prime Minister of the Republic of Slovenia Photo for print

Dr Miro Cerar, the Prime Minister of the Republic of Slovenia

Lek, a Sandoz company, awarded for cooperation in practical training of students of the Faculty of Chemistry and Chemical Technology

30. 1. 2015

At a ceremony held on 22 January 2015 at the Faculty of Chemistry and Chemical Technology, University of Ljubljana, the Maks Samec awards and recognitions for 2014 were presented for the best doctoral thesis in the field of chemistry, the best doctoral thesis in the field of chemical engineering and chemical technology and for services and merits to the Faculty in the year 2014. On this occasion, the Faculty also wanted to thank all the companies and individuals who shared their knowledge and resources to help the Faculty on its education and research path.

Lek, a Sandoz company, received a plaque for taking part in the implementation of practical training, which was collected, on behalf of the company, by Samo Roš, Head of Human Resources and a Member of the Lek Board of Management. By doing so, the Faculty of Chemistry and Chemical Technology thanked all the mentors who directly transfer their expertise and valuable experience onto students, teaching them specific skills, encouraging their development, guiding them through the work process and ensuring that students become socialized in the workplace.

* * *

Lek, a Sandoz company, is one of key pillars of the second-largest generic pharmaceutical company globally. Its role within Sandoz is to act as: a leading global development center for technologically demanding products and technologies; a global manufacturing center for active pharmaceutical ingredients and medicines; a competence center for the development of vertically integrated products; a Sandoz competence center in the field of development and manufacturing of biosimilar products; and, a supply center for the markets of Central and Eastern Europe (CEE), South East Europe (SEE) and Commonwealth of Independent States (CIS), and it is responsible for sales on the Slovenian market. For further information please visit http://www.lek.si/en.

Sandoz, the generic pharmaceuticals division of Novartis, is a global leader in the generic pharmaceutical sector. Sandoz employs over 26,400 employees and its products are available in more than 160 countries, offering a broad range of high-quality, affordable products that are no longer protected by patents. With USD 9.6 billion in sales in 2014, Sandoz has a portfolio of approximately 1,100 molecules, and holds the #1 position globally in biosimilars as well as in generic injectables, ophthalmics, dermatology and antibiotics, complemented by leading positions in the cardiovascular, metabolism, central nervous system, pain, gastrointestinal, respiratory, and hormonal therapeutic areas. Sandoz develops, produces, and markets these medicines, as well as active pharmaceutical and biotechnological substances. Nearly half of Sandoz’s portfolio is in differentiated products, which are defined as products that are more difficult to scientifically develop and manufacture than standard generics. In addition to strong organic growth since consolidating its generics businesses under the Sandoz brand name in 2003, Sandoz has benefitted from strong growth of its acquisitions, which include Lek (Slovenia), Sabex (Canada), Hexal (Germany), Eon Labs (US), EBEWE Pharma (Austria), Oriel Therapeutics (US), and Fougera Pharmaceuticals (US).
Sandoz is on Twitter. Sign up to follow @Sandoz_global at http://twitter.com/Sandoz_Global.

Novartis provides innovative healthcare solutions that address the evolving needs of patients and societies. Headquartered in Basel, Switzerland, Novartis offers a diversified portfolio to best meet these needs: innovative medicines, eye care, cost-saving generic pharmaceuticals, preventive vaccines and over-the-counter products. Novartis is the only global company with leading positions in these areas. In 2014, the Group achieved net sales of USD 58.0 billion, while R&D throughout the Group amounted to approximately USD 9.9 billion (USD 9.6 billion excluding impairment and amortization charges). Novartis Group companies employ approximately 130,000 full-time-equivalent associates. Novartis products are available in more than 180 countries around the world. For more information, please visit www.novartis.com

////////////Carbotegravir, Dolutegravir, New Patent, WO 2016113372, Lek Pharmaceutical and Chemical Co DD

WO 2016110798, Piramal Enterprises Ltd, New Patent, Lurasidone

PATENTS Comments Off

Jul 182016

Lurasidone – it having been developed and launched by Sumitomo Dainippon Pharma. Lurasidone was launched for schizophrenia in the US by Sumitomo’s US subsidiary Sunovion Pharmaceuticals.

WO 2016110798, Piramal Enterprises Ltd, New Patent, Lurasidone

An improved process for the preparation of lurasidone and its intermediate

PIRAMAL ENTERPRISES LIMITED [IN/IN]; Piramal Tower Ganpatrao Kadam Marg, Lower Parel Mumbai 400013 (IN)

GHARPURE, Milind; (IN).
TIWARI, Shashi Kant; (IN).
WAGH, Ganesh; (IN).
REVANAPPA, Galge; (IN).
WARPE, Manikrao; (IN).
ZALTE, Yogesh; (IN).

The Piramal family's purposeful philanthropy

From left: Anand Piramal, executive director, Piramal Group; Swati Piramal, vice-chairperson, Piramal Group; Ajay Piramal, chairman, Piramal Group; Nandini Piramal, executive director, Piramal Enterprises; and Peter DeYoung, president, Piramal Enterprises

Improved process for preparing pure (3aR,7aR)-4′-(benzo[d]isothiazol-3-yl)octahydrospiro[isoindole-2,1′-piperazin]-1′-ium methanesulfonate, useful as a key intermediate in the synthesis of lurasidone. Also claims a process for purifying lurasidone hydrochloride, useful for treating schizophrenia and bipolar disorders. In July 2016, Newport Premium™ reported that Piramal Enterprises was capable of producing commercial quantities of lurasidone hydrochloride and holds an active US DMF for the drug since March 2015.

Lurasidone (the Compound-I), is an atypical antipsychotic used in the treatment of schizophrenia and bipolar disorders.The drug is marketed as hydrochloride salt (the compound-I.HCl) by Sunovion Pharms Inc.under the tradename”LATUDA”, in the form of oral tablets. Latuda is indicated for the treatment of patients with schizophrenia. Lurasidone hydrochloride has the chemical name ((3aR,4S,7R,7aS)-2-[((lR,2R)-2-{ [4-(l,2-benzisothiazol-3-yl)-piperazin-l-yl]methyl}cyclohexyl)-methyl]hexahydro-lH-4,7-methanisoindol-l,3-dione hydrochloride, and is structurally represented as follows;

Compound-I.HCl

Lurasidone being an important antipsychotic agent; a number of processes for its preparation as well as for its intermediates are known in the art.

US Patent No. 5,532,372 describe a process for the synthesis of Lurasidone, which is illustrated below in Scheme-I. In the process, the compound, cyclohexane- l,2-diylbis(methylene) dimethanesulfonate(referred to as the compound-Ill) is reacted with 3-(l-piperazinyl-l,2-benzisothiazole(referred to as the compound-IV) in acetonitrile, and in the presence of sodium carbonate to provide corresponding quaternary ammonium salt as 4′-(benzo[d]isothiazol-3-yl)octahydrospiro[isoindole-2, r-piperazin]-l’-ium methanesulfonate (the compound-II). The compound-II is further treated with bicyclo[2.2.1]heptane-2-exo-3-exo-dicarboximide in xylene, in the presence of potassium carbonate and dibenzo-18-crown-6-ether to provide lurasidone.

Scheme-I

US Published Patent Application 2011/0263848 describes a process for the preparation of the quaternary ammonium salt (the compound-II) which comprises reacting 4-(l,2-benzisothiazol-3-yl)piperazine with (lR,2R)-l,2-bis(methanesulfonyloxymethyl)- cyclohexane in a solvent such as toluene in the presence of a phosphate salt.

Indian Published Patent Application 2306/MUM/2014 (” the IN’2306 Application”) describes a process for the synthesis of lurasidone and the intermediates thereof, comprising reacting (R,R) trans l,2-bis(methane sulphonyl methyl)cyclohexane with 3-(Piperazine-l-yl)benzo[d]isothiazole in presence of a mixture of two or more polar aprotic solvents selected from acetonitrile, N,N-dimethyl formamide (DMF) and/or Ν,Ν-dimethyl acetamide (DMAc), and a base at reflux temperature to obtain the quaternary ammonium salt (the compound II), which is then converted to lurasidone. The IN’2306 application demonstrated preparation of the compound II using the solvent combination such as acetonitrile-DMF and acetonitrile-DMAc.

US Published Patent Application 2011/0263847 describes a process for the preparation of the quaternary ammonium salt (the compound-II) comprising reacting 4-(l,2-benzisothiazol-3-yl)piperazine with (lR,2R)-l,2-bis(methanesulfonyloxymethyl)cyclohexane in a solvent such as toluene, wherein the piperazine compound is used in an excess amount i.e. 1.8 to 15 moles with respect to ( 1R,2R)- 1 ,2-bis(methanesulfonyloxymethyl)cyclohexane.

Chinese Published Patent Application 102731512 describes a process for the preparation of the quaternary ammonium salt (the compound-II) comprises reaction of 4-(l,2-benzisothiazol-3-yl)piperazine with (lR,2R)-l,2-bis(methanesulfonyloxymethyl)cyclohexane in a solvent such as toluene in the presence of a phase transfer catalyst.

In addition to the afore discussed patent documents, there are a number of patent documents that describe a process for the preparation of the quaternary ammonium salt (the compound-II), the key intermediate for the synthesis of lurasidone. For instance, Published PCT application WO2012/131606 A 1, Indian Published patent application 217/MUM/2013, Chinese published patent applications 102863437, 103864774 and 102827157 describe a process for the preparation of the quaternary ammonium salt (compound-II) comprises reaction of 4-(l,2-benzisothiazol-3-yl)piperazine with (lR,2R)-l,2-bis(methanesulfonyloxymethyl)cyclohexane in a solvent or a solvent mixture such as acetonitrile, acetonitrile : water solvent mixture, toluene or DMF, in the presence of a base.

It is evident from the discussion of the processes for the preparation of the quaternary ammonium salt (the compound-II), described in the afore cited patent documents that the reported processes primarily involve use of acetonitrile either as the single solvent or in a mixture of solvents. Acetonitrile is a relatively toxic, and not an environment friendly solvent. Due to its toxic nature, it can cause adverse health effects also. Acetonitrile is covered under Class 2 solvents i.e. solvents to be limited, and residual solvent limit of acetonitrile is 410 ppm in a drug substance as per the ICH (International Conference on Harmonisation) guidelines for residual solvents. Moreover, acetonitrile is a costlier solvent, which renders the process costlier and hence, is not an industrially feasible solvent.

It is also evident from the discussion of the processes described in afore cited patent documents that some of the reported processes involve use of high boiling solvents such as toluene and dimethylformamide as reaction solvent, which subsequently require high reaction temperatures, and this in turn leads to tedious workup procedures. In view of these drawbacks, there is a need to develop an industrially viable commercial process for the preparation of lurasidone and its intermediates; which is simple, efficient and cost-effective process and provides the desired compounds in improved yield and purity.

Inventors of the present invention have developed an improved process that addresses the problems associated with the processes reported in the prior art. The process of the present invention does not involve use of any toxic and/or costly solvents. Moreover, the process does not require additional purification steps and critical workup procedure. Accordingly, the present invention provides a process for the preparation of lurasidone and its intermediates, which is simple, efficient, cost effective, environmentally friendly and commercially scalable for large scale operations.

Scheme-II

Scheme-Ill

EXAMPLES

Example-1: Preparation of (3aR,7aR)-4′-(benzo[d]isothiazol-3-yl)octahydrospiro[isoindole-2,l’-piperazin]-l’-ium methanesulfonate(the compound II)

Charged 150.0 mL (3v) of isopropyl alcohol (IPA) in a flask followed by the addition of the compound-Ill (50.0 g) , 3-(l-Piperazinyl)-l, 2-Benzisothiazole (32.84 g), sodium carbonate granular (10.79 g) and water 50 mL (lv). The reaction mixture was heated at a temperature of 82-85 °C for 24 to 25 h. Cooled the reaction mixture to room temperature, filtered on Buchner funnel and the filtrate was collected.

The filtrate was evaporated under vacuum at 55-65°C till visible solid appears in the reaction mass. The solid was stirred in 75 mL of toluene at room temperature and the solid was filtered. The wet cake was transferred to a flask and added 125 mL of acetone to it; followed by stirring at room temperature. The resulting solid was filtered to yield the pure title compound (II).

Yield: 63.4 g (90 %)

Purity (by HPLC): 99.79 %

Unreacted compound-IV as impurity in 0.05 % .

Example-2: Preparation of Lurasidone free base.

Charged 150.0 mL of Ν,Ν-dimethylformamide (DMF) in a flask followed by the addition of 50.0 g of the compound-II (as obtained in the above example-1), 19.5 g (3aR,4S,7R,7aS)-4,7-methano-lH-isoindole-l,3(2H)-dione and 19.5 g of potassium carbonate. The reaction mixture was heated at a temperature of about 125 °C for 24 h. The reaction mixture was cooled to room temperature and 400 mL of water was added to it. The reaction mixture was stirred, and the precipitated product was filtered. The wet cake was washed with IPA and Lurasidone free base is obtained as the pure product. [Yield: 46.52 g (80 %)]

Example-3: Purification of Lurasidone hydrochloride.

Charged water (200 ml) and IPA (200 ml) in flask followed by the addition of Lurasidone hydrochloride (50 gm, residual acetone: 5769 ppm). The reaction mixture was heated at a temperature of 75-80 °C for about 30 min. The reaction mixture was cooled to 20-30 °C and stirred for about 2 hours. The precipitated solid was filtered and isolated as pure Lurasidone hydrochloride (residual acetone: 2 ppm)

THE VIEWS EXPRESSED ARE MY PERSONAL AND IN NO-WAY SUGGEST THE VIEWS OF THE PROFESSIONAL BODY OR THE COMPANY THAT I REPRESENT, amcrasto@gmail.com, +91 9323115463 India

///////////////WO 2016110798, Piramal Enterprises Ltd, New Patent, Lurasidone

New Patent, WO 2016110874, Artemisinin , IPCA Laboratories Ltd

PATENTS, Uncategorized Comments Off

Jul 182016

New Patent, WO 2016110874, Artemisinin , IPCA Laboratories Ltd

FOR Cancer; Parasitic infection; Plasmodium falciparum infection; Viral infection

WO-2016110874

KUMAR, Ashok; (IN).
SINGH, Dharmendra; (IN).
MAURYA, Ghanshyam; (IN).
WAKCHAURE, Yogesh; (IN)

Dr. Ashok Kumar, President – Research and Development (Chemical) at IPCA LABORATORIES LTD

IPCA LABORATORIES LIMITED [IN/IN]; 48, Kandivli Industrial Estate, Charkop, Kandivali (West), Mumbai 400067 (IN)

Novel process for preparing artemisinin or its derivatives such as dihydroartemisinin, artemether, arteether and artesunate. Also claims novel intermediates of artemesinin such as artemisinic acid or dihydroartemisinic acid. Discloses the use of artemisinin or its derivatives, for treating malaria, cancer, viral and parasitic infections.

In July 2016, Newport Premium™ reported that IPCA was capable of producing commercial quantities of artemether, arteether and artesunate; and holds an inactive US DMF for artemether since February 2009. In July 2016, IPCA’s website lists artemether, arteether and artesunate under its products and also lists artemether and artesunate as having EDMF and WHO certificates. The assignee also has Canada HPFB certificate for artemether.

The Central Drug Research Institute (CDRI) in collaboration with IPCA is developing CDRI-97/78 (1,2,4 trioxane derivative), a synthetic artemisinin substitute for treating drug resistant Plasmodium falciparum infection. In July 2016, CDRI-97/78 was reported to be in phase 1 clinical development. IPCA in collaboration with CDRI was also investigating CDRI-99/411, a synthetic artemisinin substitute for treating malaria; but its development had been presumed to have been discontinued; however, this application’s publication would suggest otherwise.

Writeup

Artemisinin is an active phytoconstituent of Chinese medicinal herb Artemisia annua, useful for the treatment of malaria. Generally, artemisinin/artemisinic acid is obtained by extraction of the plant, Artemisia annua. The plant Artemisia annua was first mentioned in an ancient Chinese medicine book written on silk in the West Han Dynasty at around 200 B.C. The plant’s anti-malarial application was first described in a Chinese pharmacopeia, titled “Chinese Handbook of Prescriptions for Emergency Treatments,” written at around 340 A.D.

Artemisinin being poorly bioavailable limits its effectiveness. Therefore semisynthetic derivatives of artemisinin such as artesunate, dihydroartemisinin, artelinate, artemether, arteether have been developed to improve the bioavailability of Artemisinin.

Artemisinin and its derivatives – dihydroartemisinin, artemether, arteether, and artesunate being a class of antimalarials compounds used for the treatment of uncomplicated, severe complicated/cerebral and multi drug resistant malaria. Additionally, there are research findings that artemisinin and its derivatives show anti-parasite, anti-cancer, and anti-viral activities.

Dihydroartemisinin Artesunate

The content of Artemisinin in the plant Artemisia annua varies significantly according to the climate and region/geographical area where it is cultivated. Further, the extraction methods provide artemisinin or artemisinic acid from the plant in very poor yields and therefore not sufficient to accommodate the ever-growing need for this important drug. Consequently, widespread use of these valuable drugs has been hampered due to the low availability of this natural product. Therefore, research has focused on the syntheses of this valuable drug in a larger scale to meet the increasing global demand and accordingly ample literature is available on the synthesis of artemisinin or its derivatives, but no commercial success being reported / known till date.

Artemisinin can be prepared synthetically from its precursors such as artemisinic acid or dihydroartemisinic acid according to literature methods known to skilled artisans. For example, dihydroartemisinic acid can be converted to artemisinin by a combination of photooxidation and air-oxidation processes as described in U.S. Patent No. 4,992,561.

Amorphadiene is an early starting material for synthesis of Artemisinic acid or dihydroartemisinic acid, which is an important intermediate for producing Artemisinin commercially, and WO2006128126 reported a preparation method as mentioned in scheme- 1.

acid

In accordance with the scheme 1, the amorphadiene is treated with di(cyclohexyl)borane ( δΗι ΒΗ followed by reaction with H2O2 in presence of NaOH to obtain the amorph-4-ene 12-ol which is further oxidized to dihydroartemisinic acid using CrCb/ifcSC^. The formation of amorph-4-ene 12-ol is taking place via epoxidation of the exocyclic double bond. However, the reported yields of this synthesis are very low, making it unviable to produce artemisinic acid at a cheaper cost than natural extraction, for commercial use.

Amorpha -4, 11-diene

A similar method is published in, WO2009088404, for synthesis of dihydroartemisinic acid through preparation of amorph-4-ene-12-ol via epoxide formation, albeit, predominantly at exo position by reacting the amorpha-4,11-diene with H2O2 in presence of porphyrin catalyst (TDCPPMnCl). During reaction, epoxidation also occurred at endo position leading to formation of Amorphadiene- 4,5- epoxide that remain as impurity. The formed exo epoxide (amorphadiene – 11, 12 – epoxide) is further reduced to get amorph- 4-ene 12-ol and then converted to dihydroartemisinic acid and finally converted into artemisinin.

Amorphadiene-11,12-epoxide

This process involves expensive & industry unfriendly reagents. Moreover, desired stereo isomers were obtained only in poor yields, because several purification steps were needed to get desired stereo isomers leading to escalated production/operational costs.

Therefore there remains a need in the art to improve the yield of Dihydroartemisinic acid, which could potentially reduce the cost of production of Artemisinin and/or its derivatives. Consequently it is the need of the hour to provide a synthetic and economically viable process to meet the growing worldwide demand by improving the process for Artemisinin and/or its derivatives to obtain them in substantially higher yields with good purity by plant friendly operations like crystallization/extractions rather than column chromatography/other cost constraint procedures.

Therefore, the object of the invention is to prepare Artemisinic acid of formula-II, Dihydroartemisinic acid of formula-IIa, Artemisinin and its derivatives through Amorphadiene- 4,5- epoxide.

DHAA methyl ester

Scheme 2

Method 4 (From compound of formula IV (R = CI)):

In the 4-neck round bottom flask was charged Diphenyl sulfoxide (23.8 g), NaHC03 (32.96 g) and DMSO (80 ml) at 30^°C. Further a solution of compound of formula IV (R = CI) (10 g) in DMSO (20 ml) was charged to the reaction mass at 30^°C followed by heating and maintaining the temperature for 40 hours at 80^°C till completion. DMSO was distilled out under vacuum. The reaction mass was cooled followed by charging water

(100 ml) and toluene (100 ml) to the reaction mass with stirring for 30 minutes at 28^°C. The layers were separated out and aqueous layer was back extracted with toluene (2 X 100 ml). The organic layer was washed with water (100 ml) and saturated brine solution (100 ml). Solvent was distilled out under vacuum at 50^°C, and the crude mass degassed under vacuum at 50-55^°C. IPA (40 ml) was charged to the mass. Simultaneous addition of hydrazine hydrate (65% in aqueous solution) (3.8 g) and hydrogen peroxide (50% in aqueous solution) (2.5 ml) was done at 30-32^°C over a period of 3.25 hours. After completion, reaction mass was cooled up to 5-10^°C and water (100ml) was added to the reaction mass. The pH of the reaction mass was adjusted to 3.8 with dilute 8% aqueous HC1 (24 ml) at 10^°C. Ethyl acetate (60 ml) was added to the reaction mass at 10^°C and stirred for 15 minutes at 15-20^°C. The layers were separated. Aqueous layer was back extracted with ethyl acetate (2 X 20 ml). The combined organic layer was washed with 10%) sodium metabisulfite solution (50 ml), water (50 ml) and saturated brine solution (50 ml). The organic layer was distilled out under vacuum at 45^°C and the obtained crude mass was degassed at 50-55^°C. To this was added DME (40 ml), Biphenyl (0.9 g) and Li-metal (1.63 g) and the reaction mass was maintained for 10 hours at 80-85^°C till reaction completion. The reaction mass was cooled up to 0-5^°C followed by drop wise addition of water within one hour, and the reaction stirred for two hours at 20-25^°C. Toluene (35 ml) was charged with stirring and layers were separated. The aqueous layer was washed with toluene (35 ml) and the combined toluene layer was washed with water (20 ml). The combined aqueous layer was again washed with toluene (20 ml). The aqueous layer was cooled to 10-15^°C and pH adjusted to 3.5-4 with dilute 16% aqueous HC1. MDC (50 ml) was charged and stirred 30 minutes at 20-25^°C followed by separation of layers. The aqueous layer extracted with MDC (25 ml) and the combined MDC layer was washed with water (50 ml), then with saturated NaCl solution (25 ml). The solvent was distilled out under vacuum at 40-45^°C and the crude mass (Purity: 70-80%>) was degassed at 65-70°C. The crude product (10 g) was dissolved in ethyl acetate (200 ml). 10%> aqueous NaOH (100 ml) was charged to the reaction mass and stirred one hour at 20^°C followed by layer separation. Again 10%> aqueous NaOH (100ml) was added to the organic layer, stirred for 30 minutes and layers were separated out. The pH of the combined NaOH solution wash was adjusted to 4.0 with dilute 16%> aqueous HC1 at 5-10^°C under stirring. Ethyl acetate (850 ml) was charged to aqueous acidic mass, stirred 30 minutes and layers were separated out. The aqueous layer was back extracted with ethyl acetate (2 X 30 ml) and the combined organic layer was washed with water (100 ml) and saturated brine (50 ml). The organic layer was dried over sodium chloride, solvent was distilled out under vacuum and the purified mass was degassed under vacuum at 50-55^°C to obtain Dihydroartemisinic acid (Purity: 90-95%).

b) Methyl ester of Dihydroartemisinic acid:

To a clear solution of Dihydroartemisinic acid (40 g) dissolved in MDC (120 ml) was added thionyl chloride (SOCh) (14.85 ml) at 10±2°C and reaction mass was heated to reflux temperature 40±2°C. After the completion of reaction, solvent was distilled out and excess SOCh was removed under reduced pressure. The resulting concentrated mass of acid chloride was dissolved in MDC (200 ml). In another RBF was taken triethylamine (30.6 ml) and methanol (120 ml). To this solution was added above acid chloride solution at 30±2°C and maintained till completion of reaction. To the reaction mass was added water (400 ml) and organic layer was separated. The aqueous layer was washed with MDC and mixed with main organic layer and the combined organic layer was back washed with water till neutral pH. Then organic layer was concentrated to give methyl ester of Dihydroartemisinic acid as a brown color oily mass.

Weight: 41.88 gm

Yield = 98%

c) Artemisinin:

Methyl ester of dihydroartemisinic acid (67.7 g) was dissolved in methanol (338 ml). To this solution was added Sodium molybdate (29.5 g), 50% hydrogen peroxide (147.3 g) was added at 30±2°C and reaction was maintained for 3-4 hours. After completion of reaction was added water (300 ml) and MDC (300 ml) to the reaction mass. The organic layer was separated and aqueous layer washed with MDC (100 ml). The combined organic layer was concentrated to 475 ml containing hydroperoxide intermediate and directly used for next stage reaction. In another RBF containing MDC (475 ml) was added benzene sulfonic acid (1.27 g) and Indion resin (6.7 g). This heterogeneous solution was saturated with oxygen by passing O2 gas for 10 min at 0±2°C. To this was added previous stage hydroperoxide solution at same temperature with continuous 02 gas purging within 30-40 minutes. The oxygen gas was passed at same temp for 4 hours and temperature raised to 15±2°C with continued passing of oxygen for 5 hours. The

mixture was stirred at 25-30°C for 8-10 hours followed by filtration of resin. The filtrate was washed with water (200 ml X 3) and the combined aqueous layer back washed with MDC (50 ml). The combined organic layer was concentrated to give crude Artemisinin. Weight: 54 gm

Yield= 70.7%

Purification of Artemisinin:

Crude Artemisinin (10 g) was dissolved in ethyl acetate (25 ml) at 45-50°C. The solution was cooled to 30-35°C followed by addition of n-Hexane (100 ml). The material was isolated, stirred for 2 hours, filtered and vacuum dried at 45°C.

Weight: 4 gm

Yield: 40%

THE VIEWS EXPRESSED ARE MY PERSONAL AND IN NO-WAY SUGGEST THE VIEWS OF THE PROFESSIONAL BODY OR THE COMPANY THAT I REPRESENT, amcrasto@gmail.com, +91 9323115463 India

////////New Patent, WO 2016110874, Artemisinin , IPCA Laboratories Ltd, malaria, Cancer, Parasitic infection, Plasmodium falciparum infection, Viral infection, artemether artemisinin, artemotil, artenimol, artesunate,

NEW PATENT, WO 2016108172, OSPEMIFENE AND FISPEMIFENE, OLON S.P.A.

PATENTS Comments Off

Jul 142016

Ospemifene is useful for treating menopause-induced vulvar and vaginal atrophy; while fispemifene is useful for treating symptoms related with male androgen deficiency and male neurological disorders.

In July 2016, Newport Premium™ reported that Olon was potentially interested in ospemifene and holds an active US DMF for ospemifene since September 2015. Olon’s website also lists ospemifene under R&D APIs portfolio.

WO2016108172

PROCESS FOR THE PREPARATION OF OSPEMIFENE AND FISPEMIFENE

OLON S.P.A. [IT/IT]; Strada Rivoltana, Km. 6/7 20090 Rodano (MI) (IT)

CRISTIANO, Tania; (IT).
ALPEGIANI, Marco; (IT)

WO2016108172

Process for preparing ospemifene or fispemifene, by reacting a phenol with an alkylating agent.

Ospemifene, the chemical name of which is 2-{4-[(lZ)-4-chloro-l,2-diphenyl-l-buten-l-yl]phenoxy}ethanol (Figure), is a non-steroidal selective oestrogen-receptor modulator (SERM) which is the active ingredient of a medicament recently approved for the treatment of menopause-induced vulvar and vaginal atrophy.

The preparation of ospemifene, which is disclosed in WO96/07402 and WO97/32574, involves the reaction sequence reported in Scheme 1 :

Ospemifene

Scheme 1

The first step involves alkylation of 1 with benzyl-(2-bromoethyl)ether under phase-transfer conditions. The resulting product 2 is reacted with triphenylphosphine and carbon tetrachloride to give chloro-derivative 3, from which the benzyl protecting group is removed by hydrogenolysis to give ospemifene.

A more direct method of preparing ospemifene is disclosed in WO2008/099059 and illustrated in Scheme 2.

Ospemifene

Scheme 2

Intermediate 5 (PG = protecting group) is obtained by alkylating 4 with a compound X-CH2-CH2-O-PG, wherein PG is a hydroxy protecting group and X is a leaving group (specifically chlorine, bromine, iodine, mesyloxy or tosyloxy), and then converted to ospemifene by removing the protecting group.

Alternatively (WO2008/099059), phenol 4 is alkylated with a compound of formula X-CH2-COO-R wherein X is a leaving group and R is an alkyl, to give a compound of formula 6, the ester group of which is then reduced to give ospemifene (Scheme 3)

Ospemifene

Scheme 3

Processes for the synthesis of ospemifene not correlated with those reported in schemes 2 and 3 are also disclosed in the following documents: CN104030896, WO2014/060640, WO2014/060639, CN103242142 and WO201 1/089385.

Fispemifene, the chemical name of which is (Z)-2-[2-[4-(4-chloro-l,2-diphenylbut-l-enyl)phenoxy]ethoxy]ethanol (Figure) is a non-steroidal selective oestrogen-receptor modulator (SERM), initially disclosed in WOO 1/36360. Publications WO2004/108645 and WO2006/024689 suggest the use of the product in the treatment and prevention of symptoms related with male androgen

deficiency. The product is at the clinical trial stage for the treatment of male neurological disorders.

According to an evaluation of the synthesis routes for ospemifene and fispemifene described in the literature, those which use compound 4 (Schemes 2 and 3) are particularly interesting, as 4 is also a key intermediate in the synthesis of toremifene, an oestrogen-receptor antagonist (ITMI20050278).

Leaving group X of the compound of formula 7 is preferably a halogen, such as chlorine, bromine or iodine, or an alkyl or arylsulphonate such as mesyloxy or tosyloxy.

In one embodiment of the invention, in the compound of formula 7, X is a leavmg group as defined above and Y is -(OCH2CH₂)_nOH wherein n is zero, and the reaction of 7 with 4 provides ospemifene, as reported in Scheme 4.

Scheme 4

In another embodiment of the invention, in the compound of formula 7, X and Y, taken together, represent an oxygen atom, the compound of formula 7 is ethylene oxide, and the reaction of 7 with 4 provides ospemifene, as reported in Scheme 5.

Scheme 5

In another embodiment of the invention, X is a leaving group as defined above and n is 1, and the reaction of 7 with 4 provides fispemifene, as reported in Scheme 6.

Scheme 6

The reaction between phenol 4 and alkylating reagent 7, wherein X is a leaving group as defined above and Y is the -(OCHbCEh^OH group as defined above, can be effected in an aprotic solvent preferably selected from ethers such as tetrahydrofuran, dioxane, dimethoxyethane, tert-butyl methyl ether, amides such as N,N-dimethylformamide, Ν,Ν-dimethylacetamide and N-methylpyrrolidone, nitriles such as acetonitrile, and hydrocarbons such as toluene and xylene, in the presence of a base preferably selected from alkoxides, amides, carbonates, oxides or hydrides of an alkali or alkaline-earth metal, such as potassium tert-butoxide, lithium bis-trimethylsilylamide, caesium and potassium carbonate, calcium oxide and sodium hydride.

The reaction can involve the formation in situ of an alkali or alkaline earth salt of phenol 4, or said salt can be isolated and then reacted with alkylating reagent 7. Examples of phenol 4 salts which can be conveniently isolated are the sodium salt and the potassium salt. Said salts can be prepared by known methods, for example by treatment with the corresponding hydroxides (see preparation of the potassium salt of phenol 4 by treatment with aqueous potassium hydroxide as described in document ITMI20050278), or from the corresponding alkoxides, such as sodium methylate in methanol for the preparation of the sodium salt of phenol 4, as described in the examples of the present application.

Example 1

Sodium hydride (4.2 g) is loaded in portions into a solution of 4-(4-chloro-l,2-diphenyl-buten-l-yl)phenol (10 g) in tetrahydrofuran (120 ml) in an inert gas environment, and the mixture is maintained under stirring at room temperature for 1 h. 2-Iodoethanol (11 ml) is added dropwise, and the reaction mixture is refluxed for about 9 h. Water is added, and the mixture is concentrated and extracted with ethyl acetate. The organic phase is washed with sodium carbonate aqueous solution and then with water, and then concentrated under vacuum. After crystallisation of the residue from methanol-water (about 5: 1), 9.9 g of crude ospemifene is obtained.

Example 2

A solution of sodium methylate in methanol (6.25 ml) is added to a solution of 4-(4-chloro-l,2-diphenyl-buten-l-yl)phenol (10 g) in methanol (100 ml) in an inert gas environment, and maintained under stirring at room temperature for 1 h. The mixture is concentrated under vacuum and taken up with tetrahydrofuran (100 ml). A solution of 2-iodoethanol (3.5 ml) in tetrahydrofuran (30 ml) is added dropwise, and the reaction mixture is refluxed for about 3 h. Water is added, and the mixture is concentrated and extracted with ethyl acetate. The organic phase is washed with a saturated sodium hydrogen carbonate aqueous solution, and finally with water. The resulting solution is then concentrated under vacuum and crystallised from methanol-water to obtain 5.8 g of crude ospemifene.

Example 3

Potassium tert-butylate (2.0 g) is added to a solution of 4-(4-chloro-l,2-diphenyl-buten-l-yl)phenol (5 g) in tert-butanol (75 ml) in an inert gas environment, and maintained under stirring at room temperature for 1 h. The solvents are concentrated under vacuum, and the concentrate is taken up with tetrahydrofuran (50 ml). A solution of 2-iodoethanol (1.7 ml) in tetrahydrofuran (15 ml) is added in about 30 minutes, and the reaction mixture is then refluxed for about 2 h. The process then continues as described in Example 1, and 2.9 g of crude ospemifene is obtained.

Example 4

A 50% potassium hydroxide aqueous solution (4.4 ml) is added to a solution of 4-(4-chloro-l,2-diphenyl-buten-l-yl)phenol (2 g) in toluene (20 ml) in an inert gas environment, and maintained under stirring at room temperature for 15

minutes. 2-Iodoethanol (2.2 ml) is added in about 30 minutes, and the reaction mixture is refluxed and maintained at that temperature for about 7 h. After the addition of water, the phases are separated. The organic phase is washed with a saturated sodium hydrogen carbonate aqueous solution, and finally with water. The organic phase is then concentrated under vacuum. After crystallisation of the residue from methanol-water (about 5:1), 0.85 g of crude ospemifene is obtained.

//////NEW PATENT, WO 2016108172, OSPEMIFENE, FISPEMIFENE, OLON S.P.A.

WO 2016092561, Ivacaftor, New patent, Laurus Labs Pvt Ltd

PATENTS Comments Off

Jun 272016

WO-2016092561, Ivacaftor, NEW PATENT

https://www.google.com/patents/WO2016092561A2?cl=en

Novel polymorphs of ivacaftor, process for its preparation and pharmaceutical composition thereof

Laurus Labs Pvt Ltd

LAURUS LABS PRIVATE LIMITED [IN/IN]; Plot No. DS1, IKP Knowledge Park, Genome Valley Turkapally, Shameerpet Mandal, Ranga District Hyderabad 500078 (IN)

Ram Thaimattam, Venkata Srinivasa Rao DAMA, Venkata Sunil Kumar Indukuri, Seeta Rama Anjaneyulu GORANTLA,Satyanarayana Chava,
Applicant	Laurus Labs Private Limited

THAIMATTAM, Ram; (IN).
DAMA, Venkata Srinivasa Rao; (IN).
INDUKURI, Venkata Sunil Kumar; (IN).
GORANTLA, Seeta Rama Anjaneyulu; (IN).
CHAVA, Satyanarayana; (IN)

Novel crystalline forms of ivacaftor (designated as forms L1 to L14), processes for their preparation and composition comprising them are claimed.

Vertex, in research collaboration with Cystic Fibrosis Foundation Therapeutics, had developed and launched ivacaftor.

Ivacaftor, also known as N-(2,4-di-tert-butyl-5-hydroxyphenyl)-l,4-dihydro-4-oxoquinoline-3-carboxamide, having the following Formula I:

Formula I

Ivacaftor was approved by FDA and marketed by Vertex pharma for the treatment of cystic fibrosis under the brand name KALYDECO^® in the form of 150 mg oral tablets.

WO2006/002421 publication discloses modulators of ATP-binding cassette transporters such as ivacaftor. This patent generally discloses a process for the preparation of modulators of ATP-binding cassette transporters such as quinoline compounds; however, specific process for the preparation of ivacaftor and its solid state details were not specifically disclosed.

WO2007/079139 publication discloses Form A, Form B and amorphous form of ivacaftor characterized by PXRD, DSC and TGA and process for their preparation. Further this publication discloses ethanol crystalate of ivacaftor in example part.

WO2009/038683 publication discloses the solid forms of ivacaftor, which are designated as Form-I (2-methylbutyric acid), Form-II (propylene glycol), Form-HI (PEG400.KOAc), Form-IV (lactic acid), Form-V (isobutyric acid), Form-VI (propionic

acid), Form- VII (ethanol), Form- VIII (2-propanol), Form-IX (monohydrate), Form-X (besylate Form A), Form-XI (besylate Form B), Form-XII (besylate Form D), Form-XIII (besylate Form E), Form-XIV (besylate Form F), Form-XV (besylate (2: 1)), Form-XVI (besylate mono hydrate). This publication also discloses the characterization details like PXRD, DSC and TGA for the above forms and process for their preparation.

WO201 1/1 16397 publication discloses crystalline Form C of ivacaftor, process for its preparation and pharmaceutical composition comprising the same. Also discloses characterization details of Form C, such as PXRD, IR, DSC and ¹³CSSNMR.

WO2013/158121 publication discloses solvated forms of ivacaftor, which are designated as Form D (acetonitrile or acetonitrile/water (75/25) solvate), Form E (Methyl ethyl ketone (MEK), MEK/water (90/1), MEK/water (90/10), MEK/water (80/20) solvate), Form F (acetonitrile/water (75/25) solvate), Form G (isopropyl acetate solvate), Form H (isopropyl acetate/water (95/5) solvate), Form I (MEK solvate), Form J (MEK/water (99/1) solvate), Form K (MEK or MEK/water (99/1) or MEK/water (90/10) or MEK/water (80/20) solvate), Form L (isopropyl acetate/water (95/5) solvate), Form M (MEK or MEK/water (99/1) solvate), Form N (MEK water (90/10) or MEK/water (80/20) solvate), Form O (MEK or MEK/water (99/1) solvate), Form P (MEK water (90/10) or MEK water (80/20) solvate), Form Q (MEK/water (80/20) solvate), Form R (acetonitrile solvate), Form S (MEK/water (80/20) solvate), Form T (isopropyl acetate/water (95/5) solvate), Form W (acetonitrile/water (90/10) solvate), Form XX (from 10% water/ acetonitrile) and hydrate B (hydrated form). This patent further discloses characterization details like PXRD and TGA for the above forms and process for their preparation.

WO2014/118805 publication discloses crystalline forms of ivacaftor designated as Form D, Form E, Form El, Form G and Form G’; amorphous ivacaftor designated as Form I and Form II; crystalline ivacaftor solvates such as n-butanol solvate, methanol solvate, propylene glycol solvate, DMF solvate, THF solvate, DMF:ethylacetate solvate. This publication further discloses the process for the preparation of said forms along with their characterization details.

WO2015/070336 publication discloses polymorphic form APO-I and MIBK solvate of ivacaftor along with its characteristic PXRD details, process for its preparation and pharmaceutical composition comprising them.

CN 104725314A publication discloses ivacaftor new polymorph D, which is obtained by crystallization of ivacaftor from acetonitrile/water. This publication further discloses characteristic details such PXRD, IR and DSC of ivacaftor new polymorph D.

Polymorphism is the occurrence of different crystalline forms of a single compound and it is a property of some compounds and complexes. Thus, polymorphs are distinct solids sharing the same molecular formula, yet each polymorph may have distinct physical properties. Therefore, a single compound may give rise to a variety of polymorphic forms where each form has different and distinct physical properties, such as different solubility profiles, different melting point temperatures and/or different x-ray diffraction peaks. Since the solubility of each polymorph may vary, identifying the existence of pharmaceutical polymorphs is essential for providing pharmaceuticals with predictable solubility profiles. It is desirable to investigate all solid state forms of a drug, including all polymorphic forms and solvates, and to determine the stability, dissolution and flow properties of each polymorphic form.

Polymorphic forms and solvates of a compound can be distinguished in a laboratory by X-ray diffraction spectroscopy and by other methods such as, infrared spectrometry. Additionally, polymorphic forms and solvates of the same drug substance or active pharmaceutical ingredient, can be administered by itself or formulated as a drug product (also known as the final or finished dosage form), and are well known in the pharmaceutical art to affect, for example, the solubility, stability, flowability, tractability and compressibility of drug substances and the safety and efficacy of drug products.

The discovery of new polymorphic forms and solvates of a pharmaceutically useful compound, like ivacaftor, may provide a new opportunity to improve the performance characteristics of a pharmaceutical product. It also adds to the material that a formulation scientist has available for designing, for example, a pharmaceutical dosage form of a drug with a targeted release profile or other desired characteristic. New polymorphic forms of the ivacaftor have now been discovered and have been designated as ivacaftor Form-Ll, Form-L2, Form-L3, Form-L4, Form-L5, Form-L6, Form-L7, Form-L8, Form-L9, Form-LlO, Form-Ll 1, Form-Ll 2 A, Form-Ll 2B, Form-Ll 3 and Form-Ll 4.

EXAMPLE 1 : Preparation of Ivacaftor Form-Ll

A suspension of ivacaftor ethanolate (5 g) in n-heptane (200 mL) was heated to 95-100°C and stirred for 5 hrs at the same temperature. Then the reaction mixture was cooled to 25-35°C and stirred for an hour. The solid obtained was filtered, washed with n-heptane and suck dried. The wet solid was further dried at 60-65°C for 16 hrs under vacuum yielded ivacaftor Form-Ll . The XRPD is set forth in Figure- 1.

In a similar manner, ivacaftor Form-Ll was prepared from different solvates of ivacaftor in place of ivacaftor ethanolate as input using the following conditions;

Ivacaftor cyclopentyl methyl ether (0.5 g) n-heptane (20 mL) 50°C/8 hr

Ivacaftor methyltertiarybutyl ether (0.5 g) n-heptane (20 mL) 50°C/8 hr

Laurus Labs: A hot startup in the pharma sector

Dr Satyanarayana Chava

Chief executive officer (CEO)

Laurus Labs Private Limited

When Dr Satyanarayana Chava started Laurus Labs in 2007, he invested nearly Rs 60 crore of his own money into it. His confidence in its success was neither bravado nor bluster, but defined by his knowledge of the pharmaceutical industry. Eight years on, the Hyderabad-based company is on track to reach revenues of Rs 2,000 crore by the end of FY2016.

Chava, now 52, has more than two decades of experience in the pharmaceutical industry; in his last job, he was chief operating officer (COO) of the successful startup, Matrix Laboratories. Of his 10 years there, he says with pride, “I never skipped a promotion and got to work in all departments.” His dedication, coupled with a sound understanding of what it takes to start a pharmaceutical company, is what makes Laurus Labs among the hottest startups in this sector.

Initially, Chava planned the business around research and development (R&D). He wanted Laurus Labs to focus on contract research and make money from royalties. “In India, companies start with manufacturing and then get into R&D,” he explains. “I did it the other way round.” He focussed his fledgling company’s resources on developing formulations for medicines, and licensed them to other pharmaceutical players. In the early months, Laurus Labs had 10 people in manufacturing and 300 in R&D.

In June 2007, Aptuit, a US-based contract research organisation (CRO), signed it on for a $20 million (then Rs 80 crore) contract. But despite this injection of funds, Chava was unable to sustain his original idea of developing technologies for other companies. At the time of the Aptuit deal, Laurus Labs’s annual revenues were not even $20,000 (Rs 8 lakh at the time). In 2008, Chava decided to start manufacturing active pharmaceutical ingredients (API), which, as the name suggests, are chemicals or key ingredients in drugs required to make the medication work. His early investment into R&D benefitted Laurus Labs; it maintains a large repository of research-based knowledge that forms the bedrock of any successful pharmaceutical business.

Today, it is a key manufacturer supplier of APIs and holds its own against better-known competitors like US generic drug giant Mylan, which, incidentally, acquired a controlling stake in Matrix around the time Chava founded Laurus Labs. It has also carved a niche for itself by supplying antiretroviral or ARVs (used to fight infections caused by retroviruses like HIV) and oncology drugs. And despite being a relatively new player, its clients include giants like Pfizer, Teva Pharmaceutical Industries and Merck.

The person behind it
A Master’s degree in chemistry was never on the cards for Chava. In the early 1980s, the best students usually studied physics, and he had planned to do the same. But when he went to his college in Amravati (Andhra Pradesh) to enroll, his elder sister’s friend suggested he study chemistry too. Chava took up the subject on a whim. He ended up liking chemistry so much so that in his final year he topped his batch despite not having written one out of the four required papers. He went on to complete his PhD in the subject in 1991.

Upon graduating, he was hired by Ranbaxy Laboratories in Delhi as a researcher. In those early years itself Chava knew he’d spend a lifetime in the industry. He enjoyed the work and gained valuable experience as a young researcher in what was then India’s finest pharmaceutical company.

But through his years in the industry, Chava was conscious of the fact that he needed to broaden his experience outside of research. His stint at Matrix Laboratories afforded him that opportunity. As it was a startup, he was able to rise through the ranks quickly and got the opportunity to work in key departments from sales and marketing to finance and accounts. Within eight years of joining Matrix, he became its COO.

This experience was to come in handy when, due to differences with the board—he refused to elaborate on this—he decided to leave Matrix and set up Laurus Labs. And though he is the company’s chief executive officer (CEO), Chava remains true to his calling as a chemist. He has strived to build an organisation that is not very hierarchical. It is not uncommon to see him interacting with the chemists in the company and discussing formulations with them—something unheard of in an industry where most CEOs are from a sales and marketing background.

Chandrakanth Chereddi

VP Synthesis Business Unit

Prior to his current assignment at Laurus Labs India, Chandra headed the Project Management division for all scientific projects at the Laurus R&D center. Chandra previously worked for McKinsey & Company in India as a member of the healthcare practice and at Google Inc. as a software engineer in Google’s Mountain View, CA office. Chandra holds a BE from the College of Engineering, Osmania University, Hyderabad, and MS from University of Illinois at Urbana-Champaign, and an MBA from Indian School of Business, Hyderabad.

///////WO 2016092561, Ivacaftor, New patent, Laurus Labs Pvt Ltd

EP 03031800, New patent, Miglustat, Navinta LLC

PATENTS, Uncategorized Comments Off

Jun 272016

MIGLUSTAT

Gauchers disease type I; Niemann Pick disease type C

EP-03031800, Process for the preparation of high purity miglustat

Navinta, LLC ; Shah, Shrenik K. ; Kharatkar, Raju Mahadev ; Bhatt, Chiragkumar Anilkumar ; Kevat, Jitendra Bhagwandas

The present invention provides a process for the preparation and isolation of crystalline miglustat without the use of a column chromatography or ion exchange purification. The crystalline miglustat has a high purity and a melting point of 128 °C and an endothermic peak is 133 °C.

Process for preparing and isolating crystalline form of miglustat with a high purity is claimed. Represents a first PCT filing from the inventors on miglustat. Actelion, under license from Oxford GlycoSciences (OGS; then Celltech, now UCB), which licensed the compound from GD Searle & Co, has developed and launched miglustat.

Product patent WO9426714, will expire in the US in 2018.

Kharatkar is affiliated with Sterling Biotech, Bhatt is affiliated with Intas and Kevat is affiliated with Orchid Chemicals & Pharmaceuticals.

INVENTORS Shah, Shrenik K.; Kharatkar, Raju Mahadev; Bhatt, Chiragkumar Anilkumar; Kevat, Jitendra Bhagwandas

About Navinta

Navinta, LLC in Ewing, N.J. is a technology driven Pharmaceutical Company that focuses on novel routes of synthesis of new and existing drug molecules, complex pharmaceutical ingredients, novel formulations of liquid dosage form, novel oral dosage form, novel injectable dosage form and implantable drug delivery devices. Navinta has currently at least fifteen (15) patents granted or pending with the United States Patent and Trademark Office.

EP-03031800 LINK EMBEDDED

Miglustat is a potent inhibitor of glycosyltransferase. It is primarily used in the treatment of Gaucher’s disease. Miglustat is chemically known as N-butyl-1,5-dideoxy-1,5-imino-D-glucitol of formula (I) and is sometimes referred as N-butyl-1-deoxynojirimycin. Miglustat is a white to off-white crystalline solid with a melting point of 125-126° C. Its empirical formula is C₁₀H₂₁NO₄and has a molecular weight of 219.28 g/mol.

(MOL) (CDX)

Miglustat belongs to the class of azasugars or iminosugars. Ever since the discovery of iminosugars in the 1960s, iminosugars have been subject of extensive studies in both the organic chemistry and biochemistry fields. Iminosugars are polyhydroxylated alkaloids, which may be described as monosaccharide analogues with nitrogen replacing oxygen in the ring. A well-known member of this extensive family of compounds is 1-deoxynojirimycin of formula (II).

(MOL) (CDX)

1-Deoxynojirimycin was initially synthesized in a laboratory. Subsequently, 1-deoxynojirimycin was isolated from natural sources, such as from leaves of mulberry trees and certain species of bacteria. 1-Deoxynojirimycin was shown to be an enzyme inhibitor.

Further research on 1-deoxynojirimycin analogs revealed that N-alkylated derivatives of 1-deoxynojirimycin exhibited greater biological activity than 1-deoxynojirimycin. Among them, N-butyl-1-deoxynojirimycin or miglustat of formula (I), was identified as a very potent inhibitor of glycosyltransferase. Miglustat was later approved by the FDA for human use.

Preparation of azasugars has been a very active area of research for a long time. A seminal synthesis of the compounds of formulas (I) and (II) by double reductive aminations of 5-keto-D-glucose was developed by Baxter and Reitz (J. Org. Chem. 1994, 59, 3175). This method was later refined by Matos and Lopes (Synthesis 1999, 571), in which tetra-O-benzyl-glucose was used as a starting material. Synthesis of miglustat can be traced back to 1977, when chemists from Bayer reported a synthesis of miglustat from 1-deoxynojirimycin and patented in U.S. Pat. No. 4,639,436. Other variations of this general scheme have also appeared in patents and non-patent literature, for example, U.S. Pat. No. 8,802,155 and U.S. Application Publication No. 2014/0243369.

A major drawback of those protocols is that all of them require the use of ion-exchange resins for purification of miglustat. In those protocols, an aqueous solution of miglustat obtained after running an ion-exchange column was concentrated to isolate miglustat. Due to the presence of four hydroxyl groups and a tertiary amine moiety in its chemical structure, miglustat is extremely hydrophilic. Thus, isolation of miglustat from an aqueous solution is quite challenging. In particular, it was very difficult to remove diastereomers and inorganic impurities formed during the reactions from miglustat by those protocols. Sometimes a second chromatographic purification was required to separate these impurities from miglustat. As a result, the yields of miglustat were generally low. The requirement to use a column purification (e.g. ion exchange column, flash column chromatography) further limits the scale of miglustat that could be prepared.

Scheme 1 is a synthetic scheme of miglustat in accordance with one embodiment of the invention:

(MOL) (CDX)

As depicted in scheme 1, the method of preparing miglustat may include the steps of: (1) providing or synthesizing a compound of formula (V); (2) conducting a reductive amination to provide a compound of formula (VI); (3) performing a hydrogenation reaction; and (4) isolating a free base miglustat.

The starting material, 2,3,4,6-tetra-O-benzyl-1-deoxynojirimycin hydrochloride of formula (V) may be prepared by following the methods described in Organic Process Research and Development, 2008, 12, 414-423.

Example 1

Synthesis of 2, 3, 4, 6-tetra-O-benzyl-N-butyl-1-deoxynojirimycin hydrochloride of Formula (VI)

To a solution of 2, 3, 4, 6-tetra-O-benzyl-1-deoxynojirimycin hydrochloride (V) (prepared as in Organic Process Research & Development, 2008, 12, 414-423) (45 g, 0.08 mol) in 1575 mL of methanol, n-butyraldehyde (21.6 g, 0.24 mol) and sodium cyanoborohydride (25.2 g, 0.4 mol) were added and stirred. The reaction was maintained under stirring at a temperature from about 25.degree. C. to about 30.degree. C. After the completion of the reaction, the reaction was quenched by adding 765 ml of 10% HCl in methanol, while keeping the temperature between 25.degree. C. to 30.degree. C. The reaction mass was cooled to 0.degree. C. to 5.degree. C. and the resulting precipitate solids were filtered. The filtrate was treated with aqueous HCl and the solid formed was filtered, suspended in 1 N HCl, stirred for 1 hour and filtered. The collected solid was washed with diisopropylether and dried under vacuum to furnish 46.2 g of compound (IV) (46.2 g, 0.075 mol, 94% yield) of high chemical purity based on HPLC analysis (>99.0%).

Example 2

Synthesis of Miglustat Hydrochloride of Formula (III)

A solution of 2, 3, 4, 6-tetra-O-benzyl-N-butyl-1-deoxynojirimycin hydrochloride (VI) (100 g, 0.16 mol) in methanol (1000 mL), 10% HCl solution in methanol (100 mL), and 10% Pd/C (50% wet) (10 g) were mixed and stirred under hydrogen atmosphere at a temperature of about 25.degree. C. to about 30.degree. C. until completion of the reaction. The reaction mass was filtered and the solvent was removed from the filtrate by rotary evaporation. Ethyl acetate (1000 mL) was added to the residue from the rotary evaporation to precipitate the solid. The solid was filtered and dried to isolate Miglustat hydrochloride (III) (42 g, 0.16 mol, 100% yield) of >99.5% purity as measured by HPLC analysis. The DSC thermogram of this product is provided as FIG. 3, and the FTIR spectrum of this product is provided as FIG. 4.

Example 3

Synthesis of Miglustat of Formula (I)

Miglustat hydrochloride (III) (42 g, 0.16 mol) obtained from Example 2 was dissolved in 420 mL of methanol and DBU (1,8-diazabicycloundec-7-ene) (34.1 mL) was added. The reaction mass was warmed slightly and stirred for about 2 hours. The reaction was concentrated by removal of methanol. Dichloromethane (900 mL) was added to the residue. The resulting solid was filtered and dried to obtain crystalline miglustat (I) (27 g, 0.12 mol, 75% yield) of >99.5% purity as measured by HPLC analysis. The melting point of the crystalline miglustat (I) is 128.degree. C. The DSC thermogram and FTIR spectrum of the product are provided as FIG. 1 and FIG. 2, respectively. The crystalline miglustat (I) contained <0.05% of the 5R isomer (IV) as measured by HPLC.

////////////EP 03031800, new patent, miglustat, Kharatkar, Sterling Biotech, Bhatt, Intas , Kevat, Orchid Chemicals & Pharmaceuticals.

Billion-Dollar Products Coming Off Patent in 2016

PATENTS Comments Off

Jun 262016

2016 Patent Expirations .

READ AT

http://lab.express-scripts.com/lab/insights/drug-options/2016-drug-pipeline-full-of-blockbuster-potential

CUBICIN OFF PATENT IN 2016 IN US

JAPAN 2016

Blopress

BARACLUDE IN JAPAN IN 2016

ENTECAVIR, BARACLUDE

Vfend (Voriconazole) IN UK

According to a report by DCAT, based on IMS analysis, the following are some of the key patent expiries between 2014 and 2018.

Nexium (esomeprazole): This patent expired in May 2014. Innovator AstraZeneca granted a license to Teva (TEVA) to produce the generic form in the United States.
Celebrex (celecoxib): This patent expired in 2014. Pfizer conceded the drug to generic drug makers Actavis (ACT) and Teva after a prolonged lawsuit.
Symbicort (budesonide/formoterol fumarate dihydrate): Some of AstraZeneca’s 13 patents have expired, but all won’t expire until 2023. No generic version of the drug exists.
Crestor (rosuvastatin): AstraZeneca will lose its patent protection for Crestor in 2016.
Cialis (tadalafi): Eli Lilly (LLY) is set to lose patent protection in the United States and Europe in 2017.

THE VIEWS EXPRESSED ARE MY PERSONAL AND IN NO-WAY SUGGEST THE VIEWS OF THE PROFESSIONAL BODY OR THE COMPANY THAT I REPRESENT, amcrasto@gmail.com, +91 9323115463 India

Ranking (by highest sales forecasts for 2020)

	Drug	Disease	Pharmaceutical Company	2020 Forecast Sales (US $ billions)
1	Obeticholic acid	Chronic liver diseases, primarily primary biliary cirrhosis	Intercept Pharmaceuticals and Sumitomo Dainippon Pharma	2.621
2	Emtricitabine + tenofovir alafenamide (F/TAF)	HIV-1 infection	Gilead Sciences and Japan Tobacco	2.006
3	Tenofovir alafenamide + emtricitabine + rilpivirine (R/F/TAF)	HIV-1 infection	Gilead Sciences and Janssen R&D	1.572
4	MK-5172A (grazoprevir + elbasvir)	HCV infection	Merck & Co	1.537
5	Venetoclax	Chronic lymphocytic leukemia	Abbvie	1.477
6	Nuplazid (pimavanserin)	Parkinson’s disease psychosis	ACADIA Pharmaceuticals	1.409
7	Uptravi (selexipag)	Pulmonary arterial hypertension	Nippon Shinyaku Co and Actelion	1.268

2016 DRUGS-TO-WATCH FORECAST SALES RANKINGS

Analysis based on data accessed on January 08, 2016.

(SOURCE: Thomson Reuters Cortellis)

SOME SELECTED STRUCTURES

Obeticholic acid

2Grazoprevir

3 Venetoclax

4 Pimavanserin

New Blockbuster Drugs to Watch in 2016

Each of these new drugs could rake in $2 billion in sales.

Blockbuster drugs, those medicines that bring in more than $1 billion in sales every year, are the holy grail of drug development. They can make a pharmaceutical company and send them to rock-star status among investors, as evidenced by the rise of Gilead Sciences after the launch of its hepatitis C treatments. This year’s slate of new drug launches features at least seven drugs expected to hit blockbuster status within the next five years, according to a study by Thomson Reuters.

The line-up also reveals key trends within the pharmaceutical industry for this year and beyond, including an increasing focus on rare diseases, the development of more convenient single-dose regimens, and more affordable treatments.

Here are the seven drugs set to launch this year and reach blockbuster status by 2020.

1. Intercept Pharmaceuticals and Sumitomo Dainippon Pharma

Drug: Obeticholic acid

Indication: Chronic liver diseases, primarily primary biliary cirrhosis

2020 Forecast Sales: $2.62 billion

Intercept Pharmaceuticals’ ICPT -7.35% obeticholic acid has proved very effective in treating non-alcoholic steatohepatitis, a type of liver inflammation caused by fat build-up in the organ. This condition has no approved treatment and a potentially large market, which is expected to push the drug to blockbuster status, if approved. About 2% to 3% of the global population has non-alcholoic steatohepatitis and the share will likely increase due to rising rates of pre-disposing factors like obesity and insulin resistance.

2. Gilead Sciences and Japan Tobacco

Drug: Emtricitabine and tenofovir alafenamide (F/TAF)

Indication: HIV-1 infection

2020 Forecast Sales: $2 billion

Gilead’s GILD -3.48% two HIV-1 infection drugs in development are both expected to be big money-makers, and the company is hoping the new daily single-dosage options will be able to replace sales of its existing HIV treatments that are set to lose patent protections in 2017. The new TAF-based therapies show evidence that they are potentially a safer replacement for some current therapies, including Gilead’s own Truvada.

3. Gilead Sciences and Janssen R&D

Drug: Tenofovir alafenamide and emtricitabine and rilpivirine (R/F/TAF)

Indication: HIV-1 infection

2020 Forecast Sales: $1.57 billion

Like the No. 2 drug on this list, Gilead’s secondary TAF-based combination therapy in partnership with Johnson & Johnson’s JNJ -1.49% Janssen unit is expected to improve renal and bone mineral density measurements compared with some existing drugs. Those results combined with the improved longevity of HIV patients and increasing numbers of those eligible for antiretroviral drugs means a large and lucrative market for the two new TAF-based drugs.

Tenofovir alafenamide

4. Merck & Co.

Drug: MK-5172A

Indication: Hepatitis C virus

2020 Forecast Sales: $1.54 billion

Merck MRK -3.12% is getting ready to enter the heated market for hepatitis C treatments, going up against Gilead’s Harvoni and Abbvie’s Viekira Pak. Following a significant setback when theFood and Drug Administration withdrew its “breakthrough drug” status, Merck’s treatment could finally launch this year to give another safe and high-quality treatment for the disease. A recent warning by the FDA concerning Viekira Pak has dampened sales of Abbvie’s drug, which could give Merck a leg up when it eventually brings its hepatitis C drug to market. It could also pursue an aggressive pricing strategy to gain market share, given the currently high price tags on current treatments.

5. Abbvie

Drug: Venetoclax

Indication: Chronic lymphocytic leukemia

2020 Forecast Sales: $1.48 billion

Abbvie’s ABBV -2.37% Venetoclax is a potential oral treatment for cancer, primarily focused on a type of chronic lymphocytic leukemia that is resistant to chemotherapy. The drug was a leading therapy at last year’s annual meeting of the American Society of Hematology after a clinical trial showed an overall response rate of 79.4% in patients with relapsed chronic lymphocytic leukemia. The drug is also being tested as a potential treatment for other hematological cancers like non-Hodgkin’s lymphoma, as well as in combination with tamoxifen in patients with metastatic breast cancer.

6. ACADIA Pharmaceuticals

Drug: Nuplazid

Indication: Parkinson’s disease psychosis

2020 Forecast Sales: $1.41 billion

ACADIA’s ACAD -6.18% nuplazid could be the first and only drug on the market to help treat Parkinson’s disease psychosis, which affects up to 40% of Parkinson’s patients. Clinical trials have shown that the drug does not worsen motor symptoms, a vital factor for these patients, while improving night-time sleep, daytime wakefulness, and caregiver burden. Nuplazid may also work in other psychosis settings, such as schizophrenia and Alzheimer’s disease psychosis. The combination of those three diseases means ACADIA’s drug has a potentially massive and therefore lucrative market.

7. Nippon Shinyaku and Actelion

Drug: Uptravi

Selexipag

Indication: Pulmonary arterial hypertension

2020 Forecast Sales: $1.27 billion

Nippon Shinyaky’s Uptravi is able to both delay the progression of pulmonary arterial hypertension, a type of high blood pressure that affects arteries in the lungs and heart, as well as reduce the risk of hospitalization. The drug is the only one on this list that’s already available. It entered the market in the first week of January 2016 and is expected to bring in $189 million in its first year, with sales increasing to $1.27 billion by 2020. Uptravi is being promoted as an additional therapy once baseline treatment has been started. A massive clinical trial showed that Uptravi reduced the risk of death from pulmonary arterial hypertension by 39% versus placebo.

2015

Opdivo, Bristol-Myers Squibb, $5.684 billion
Praluent, Regeneron Pharmaceuticals and Sanofi, $4.414 billion
LCZ-696, Novartis, $3.731 billion
Ibrance, Pfizer, $2.756 billion
Iumacaftor plus ivacaftor, Vertex Pharmaceuticals, $2.737 billion
Viekira Pak, AbbieVie, $2.500 billion
Evolocumab, Amgen and Astellas Pharma, $1.862 billion
Gardasil 9, Merck & Co., $1.637 billion
Brexpiprazole, Ostuka Pharmaceutical and Lundbeck, $1.353 billion
Toujeo, Sanofi, $1.265 billion
Cosentyx, Novartis, $1.082 billion

SOME MORE STRUCTURES

Rilpivirine

Elbasvir

Opdivo

Quetiapine

The pharmaceuticals losing patent protection in 2016

A review of the drugs to watch in 2016 identifies several key areas of continued focus in the pharmaceutical industry: rare diseases, FDC regimens and pricing. The year ahead is anticipated to be a very interesting, and challenging, one for the pharmaceutical industry.

THE VIEWS EXPRESSED ARE MY PERSONAL AND IN NO-WAY SUGGEST THE VIEWS OF THE PROFESSIONAL BODY OR THE COMPANY THAT I REPRESENT, amcrasto@gmail.com, +91 9323115463 India

Lurasidone hydrochloride, Jubilant Generics Ltd, WO 2016059649, New patent

PATENTS Comments Off

Apr 282016

Lurasidone

Lurasidone hydrochloride, Jubilant Life Sciences Ltd, WO 2016059649, New patent

An improved process for the preparation of lurasidone hydrochloride

Jubilant Life Sciences Ltd

WO 2016059649

JUBILANT GENERICS LIMITED (FORMERLY JUBILANT LIFE SCIENCES DIVISION) [IN/IN]; Plot 1A, Sector 16 A, NOIDA Uttar Pradesh 201301 (IN)

MISHRA, Vaibhav; (IN).
DUBEY, Shailendr; (IN).
SINGH, Kumber; (IN).
CHOUDHARY, Alka Srivastava; (IN).
VIR, Dharam; (IN)

Disclosed herein is an improved process for the preparation of Lurasidone and its pharmaceutically acceptable salts via novel intermediate and use thereof for the preparation of an antipsychotic agent useful for the treatment of schizophrenia and bipolar disorder. Further, present invention provides a cost effective and eco-friendly process for producing Lurasidone hydrochloride of formula (I) substantially free of residual solvent(s) at industrial scale.

Improved process for preparing lurasidone or its hydrochloride, substantially free of residual solvent, useful for treating schizopherenia and bipolar disorder. Also claims novel intermediate of lurasidone eg ((R,R)-cyclohexane-1,2-diyl)bis((1H-imidazol-1-yl)methanone) and its preparation method.

In April 2016, Newport Premium™ reported that Jubilant Life Sciences was capable of producing commercial quantities of lurasidone and lists the drug as a molecule available under research and development on the company’s website.

This is the first patenting to be seen from Jubilant Life Sciences that focuses on lurasidone – it having been developed and launched by Sumitomo Dainippon Pharma and EU licensee Takeda, for treating schizophrenia.

May 2, 2014

Neeraj Agrawal: Took charge of API business for Jubilant Life Sciences at the age of 31

Position: CEO Generics, Jubilant Life Sciences

Education: IIIM-C, MBA, 1998; IIT, Bombay, Electrical Engg., 1995.

Previous Jobs: Associate-Business Strategy, Operations Improvement, McKinsey & Co.

Claim to Fame: Took charge of the API business for Jubilant when he was just 31-years-old

Management mantra: It revolves around trust, freedom and teams. I like my team to think and act like an entrepreneur – assess business risks and rewards suitably and then take decisions.

Lurasidone and its pharmaceutically acceptable salts like lurasidone hydrochloride is chemically, (3a ?,45,7 ?,7a5)-2-{ (1 ?,2 ?)-2-[4-(l,2-benzisothiazol-3-yl)piperazin-lyl-methyl] cyclohexylmethyl }hexahydro-4,7-methano-2H-isoindole- 1 ,3 -dione hydrochloride and has the structure represented by the Formula (I):

Formula-I

Lurasidone hydrochloride is marketed in the United States under the trade name Latuda®. Lurasidone and its pharmaceutically acceptable salts as well as process for their preparation was first disclosed in US patent no. 5,532,372. The patent discloses the preparation of lurasidone hydrochloride using racemic trans 1,2-cyclohexane dicarboxylic acid. Racemic trans 1,2-cyclohexane dicarboxylic acid on reduction with lithium aluminium hydride in THF at reflux temperature forms l,2-bis(hydroxymethyl)cyclohexane which is converted into racemic iran5-l,2-bis(methanesulfonyloxymethyl)cyclohexane by reaction with methane sulfonyl halide. l-(l,2-benzisothiazol-3-yl)piperazine on reaction with trans-l, 2-b (methanesulfonyloxymethyl)cyclohexane in the presence of sodium carbonate and acetonitrile forms iran5-3a,7a-octahydroisoindolium-2-spiro- -[4′-(l,2-benzisothiazol-3-yl)]piperazine methanesulfonate which on reaction with bicyclo[2.2.1]heptane-2-exo-3-exo-dicarboximide in the presence of potassium carbonate, dibenzo-18-crown-6-ether and xylene on refluxing forms racemic lurasidone free base. The compound is obtained by column chromatography and then treated the resulting lurasidone free base with IPA.HCl in acetone to obtain racemic lurasidone hydrochloride. Resolution of racemic lurasidone hydrochloride is carried out using tartaric acid as resolving agent. The process involves use of lithium aluminium hydride which is highly pyrophoric reagent and is not to utilize the same on commercial scale due to its handling problems associated with its reactivity. Also, the use of the column chromatography for purification is not viable on commercial scale. Further the process involves the usage of dibenzo-18-crown-6-ether as a phase transfer catalyst which is costly material and in turn increases the cost of production. Carrying out the resolution in the last stages is difficult due to the presence of six chiral centres in lurasidone and is also not suitable for an industrial scale preparation as it affects the overall yield and cost of the manufacturing process.

Chinese patent application no. CN102731512 discloses a process for preparation of lurasidone which comprises reaction of racemic irans-l,2-bis(methanesulfonyloxymethyl) cyclohexane and l-(l,2-benzisothiazol-3-yl)piperazine in toluene in the presence of sodium carbonate or potassium carbonate having particle size less than 200 micron and tetrabutyl ammonium bromide to give the intermediate /rans-3a,7a-octahydroisoindolium-2-spiro- -[4′-(l,2-benzisothiazol-3-yl)]piperazinemethanesulfonate which on reaction with bicyclo[2.2.1]heptane-2-exo-3-exo-dicarboximide in toluene using potassium carbonate having particle size less than 200 micron forms racemic lurasidone free base. The racemic free base is converted into racemic hydrochloride salt using acetone and cone, hydrochloric acid. Racemic lurasidone hydrochloride is resolved by following the method disclosed in US patent no. 5,532,372. The process involves resolution of product in the last stage which is not commercially viable as it affects the overall yield and cost of the manufacturing process.

Japanese patent no. JP4219696 discloses the resolution of trans 1,2-cycloheaxne dicarboxylic acid using (lS,2R)-(+)-norephedrine or (lR,2S)-(-)norephedrine to provide (R,R)-trans 1 ,2-cyclohexanedicarboxylic acid. The (R,R)-iran,sl,2-cyclohexane dicarboxylic acid obtained was esterified with ethanol and the obtained ester compound was reduced with vitride to provide (R,R)-l,2-bis(hydroxymethyl)cyclohexane followed by treatment with methane sulfonyl chloride to form (R,R)-1,2-bis(methanesulfonyloxymethyl)cyclohexane. The process requires large quantity of reducing agent viz., for reducing one lg of compound about 5g of reducing agent is required which is not conducive for industrial production.

Chinese patent application no. CN 102952001 discloses a process for the preparation of (lR,2R)cyclohexane-l,2-dimethanol by the reduction of (lR,2R)cyclohexane-l,2-

dicarboxylic acid using sodium borohydride or potassium borohydride and boron triflouoride diethyl ether in THF or diethyl ether as solvent. Boron triflouoride diethyl ether is used in large quantity and quite expensive which makes the process commercially unviable.

International publications no. WO 2012/131606 and WO 2014/037886 disclose a process for preparation of lurasidone which involves separating the racemic transl,2-cyclohexane dicarboxylic acid into its (R,R) trans and (S,S) trans isomers and then using the desired trans (R,R) isomer for the preparation of lurasidone hydrochloride using the chemistry disclosed in US patent no. 5,532,372 for preparation of racemic lurasidone hydrochloride. In these publications diisobutyl aluminium hydride (DIBAL) is used as the reducing agent for the preparation of (1R,2R) cyclohexane 1,2-dimethanol from (1R,2R) cyclohexane 1,2-dicarboxylic acid which is quite expensive. Further the process involves the usage of dibenzo-18-crown-6-ether as a phase transfer catalyst which is costly material and in turn increases the cost of production.

Some of the prior art processes disclose the process for the preparation of lurasidone hydrochloride from l,2-(lR,2R)-bis-(methanesulfonyloxymethyl)cyclohexane using different solvents and bases.

US patent no. 8,853,395 discloses a process for the preparation of lurasidone in which condensation of iran5-l,2-bis(methanesulfonyloxymethyl)cyclohexane with 1-(1,2-benz isothiazol-3-yl)piperazine and condensation of /rans-3a,7a-octahydroisoindolium-2-spiro- -[4′-(l,2-benzisothiazol-3-yl)]piperazine methanesulfonate with bicyclo[2.2.1] heptane-2-exo-3-exo-dicarboximide is carried out using organic bases with a ρ¾ higher than 10 such as l,4-diazabicycloundec-7-ene (DBU), l,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,4-diaza bicyclo[2.2.2] -octane (DABCO). These organic bases are comparatively expensive.

Indian patent application no. IN 2306/MUM/2014 and Chinese patent applications no. CN 102863437 and CN 103864774 disclose the use of dimethyl formamide (DMF), dimethyl sulphoxide (DMSO), dimethyl acetamide (DMA) and N-methyl pyrrolidine (NMP) for the condensation of iran5-3a,7a-octahydroisoindolium-2-spiro- -[4′-(l,2-benzisothiazol-3-yl)] piperazine methanesulfonate with bicyclo[2.2.1] heptane-2-exo-3-exo-dicarboximide to form lurasidone. These solvents have high boiling point so not preferred at commercial scale.

Some of the prior art processes are related to reduction of impurities or quality improvement of lurasidone hydrochloride.

International publication no. WO2011/136383 discloses a process for the preparation of lurasidone hydrochloride in which amount of by products are reduced by increasing the quantity of l-(l,2-benzisothiazol-3-yl)piperazine instead of sodium carbonate or potassium carbonate as base in the reaction mixture. Increasing the amount of l-(l,2-benzisothiazol-3-yl)piperazine causes an increase in cost of production and removal of excess compound makes the process less commercially viable.

International publication no. WO2011/136384 discloses a process for the preparation of lurasidone hydrochloride in which amount of by products are reduced by using dibasic potassium phosphate with a small amount of water as a base instead of sodium carbonate. Use of dibasic potassium phosphate as a base causes an increase in cost of production as dibasic potassium phosphate is expensive.

International publication no. WO2013/014665 discloses various processes for the preparation of lurasidone hydrochloride. In general the process is shown below:

Formula-(I)

In this process iran5-(lR,2R)-2-(aminomethyl)cyclohexyl)methanol of Formula (B) is first reacted with bicyclo[2.2.1]heptane-2-exo-3-exo-dicarboximide of Formula (A) to form (3aR,4S,7R,7aS)-2-(((lR,2R)-2-(hydroxymethyl)cyclohexyl)methyl)hexahydro-lH-4,7-methanoisoindole-l,3(2H)-dione of Formula (C) which on reaction with methane sulphonyl chloride followed by reaction with l-(l,2-benzisothiazol-3-yl)piperazine of Formula (D) forms lurasidone free base which was converted into lurasidone hydrochloride using acetone and cone, hydrochloric acid.

Some of the prior art processes disclose various combinations of hydrogen chloride and solvent for the preparation of lurasidone hydrochloride from lurasidone free base.

US 7,605,260 discloses use of acetone and aqueous HC1 having strength 1.8-14.4 % for preparing lurasidone hydrochloride. The yield of lurasidone hydrochloride is relatively low (85%) by this method. If the acid concentration during the salt formation is more than 5.0% then acetone quantity as the residual solvent in the reaction product is found to be greater than 0.5% in our hands which is above the ICH limits. If acid concentration during the salt formation is less than 1.8%, then yield is reduced drastically to 65%. Therefore, this method has limitations on the large-scale industrial production.

Chinese patent application no. CN102746289A discloses the process for the preparation of lurasidone hydrochloride by adding a mixture of acetone and aqueous HC1 to a solution of lurasidone free base in acetone. On reproducing this process in laboratory, it was observed that the XRPD of the product obtained does not match with XRPD of lurasidone hydrochloride.

Indian patent application IN 777/MUM/2013 discloses use of IPA, water and 35% Aqueous HC1 for the preparation of lurasidone hydrochloride. The IPA content in the product was found to be more than 5000ppm.

The methods described in the prior art are not suitable for large scale commercial production as the residual solvent is out of the ICH limits and thus the product obtained can’t be used as a drug. In order to keep the residual solvent(s) within ICH limits, repeated crystallization/purification are required which results in reduced yield and make the process quite expensive.

The prior art discloses various processes for the preparation of lurasidone hydrochloride and its intermediates. However, there still remains a need for alternative process for the preparation of lurasidone and its pharmaceutically acceptable salts substantially free of residual solvent(s) which can be used as a drug.

According to another embodiment of the present invention, novel process for the preparation of the compound of Formula (III), their isomers and pharmaceutically acceptable salts thereof, comprises condensing 1,2-cyclohexane dicarboxylic acid of Formula (II), their isomers with carbonyl diimidazole, optionally in a solvent.

(IV)

Formula (III)

NaBH₄ RT /H₂0

Formula (VII)

Scheme-1:

Example-1

Synthesis of trans(R,R)-l,2-cyclo exane dicarboxylic acid

A round bottom flask was charged with methanol (500 mL), IPA (500 mL) and trans (racemic)-l,2-cyclohexane dicarboxylic acid (100 g). In this reaction mass (R)-l-phenylethyl amine (74 mL) was added over a period of 30 minutes and stirred for 2-3 hrs at 30-40 °C. The solid obtained was filtered, washed with methanol and IPA solution (50+50 mL) and dried under reduced pressure to obtain crude salt of iran5(R,R)-l,2-cyclohexane dicarboxylic acid. The obtained salt was stirred in a solution of methanol (500 mL) and IPA (500 mL) at 65-70 °C for 2-3 hours, cooled to room temperature and filtered. The solid was washed with methanol and IPA solution (50+50 mL) and dried under reduced pressure. The solid thus obtained was dissolved in about 2N hydrochloric acid and extracted two times with ethyl acetate (1000 mL+200 mL). Organic layers were combined and washed with brine solution (100 mL). Ethyl acetate was distilled off under vacuum at 50-55 °C and cyclohexane was added to the residue. The solid separated out was filtered and washed with cyclohexane and dried under vacuum at 45-50 °C for 8-10 hours. Yield = 29.4 g

Example-2

Synthesis of ((R,R)-cyclohexane-L2-diyl)bis((lH-imidazol-l-yl)methanone)

To a solution of iran5(R,R)-l,2-cyclohexane dicarboxylic acid (25.0 g) in THF (250 mL), carbonyl diimidazole (60 g) is added and stirred for one hour at 25-30 °C . To the said solution of (R,R)2-(((lH-imidazole-lcarbonyl)oxy)carbonyl)cyclohexanecarboxylic acetic anhydride lH-imidazole (25.0 g) in THF (250 mL) is stirred for one hour at 45-50 °C. The compound obtained is isolated and is characterized by mass and NMR.

[m z = 272.75; 1H-NMR: 8.24 (s, 2H), 7.72 (d, 2H); 7.50 (d, 2H), 3.5 (m, 2H), 2.26-1.50 (m, 8H)]

Example-3

Synthesis of tra»,s(R,R)-l,2- bis(hydroxymethyl)cyclohexane

To a solution of ((R,R)-cyclohexane-l,2-diyl)bis((lH-imidazol-l-yl)methanone) (25 g) in THF (250 mL), sodium borohydride (22.0 g) followed by water (44.0 mL) are added and stirred for one hour. To this reaction mass, 10% solution of acetic acid (500 mL) and dichloromethane (500 mL) are added, stirred and layers separated. The organic layer is washed with 10% sodium bicarbonate solution followed by water. The dichloromethane is distilled off from organic layer under vacuum to give an oily mass. To the oily mass

dichloromethane (100 mL), water (100 mL) and 12.5mL cone, hydrochloric acid (35%) are added, stirred and layers obtained are separated. The dichloromethane is distilled off completely from organic layer at 40 °C to obtain oily mass (15.5 g).

Example-4

One pot process for synthesis of trans(R,R)-l,2- bis(hydroxymethyl)cyclohexane from trans(R,R)-l,2-cyclo exane dicarboxylic acid

To a solution of iran5(R,R)-l,2-cyclohexane dicarboxylic acid (25.0 g) in THF (250 mL), carbonyl diimidazole (60 g) was added and stirred for one hour at 25-30 °C. To the intermediate obtained sodium borohydride (22.0 g) and water (44.0 mL) were added and stirred for one hour. To this reaction mass, 10% solution of acetic acid (500 mL) and dichloromethane (500 mL) were added, stirred and layers separated. The aqueous layer was washed with dichloromethane (250 mL). The organic layer was washed with 10% sodium bicarbonate solution followed by water. The dichloromethane is distilled off from organic layer under vacuum to give an oily mass. To the oily mass dichloromethane (100 mL), water (100 mL) and 12.5mL cone, hydrochloric acid (35%) were added, stirred and layers obtained were separated. The dichloromethane was distilled off completely at 40 °C to obtain oily mass (15.5 g).

Example-5

Synthesis of m¾ns(R,R)- 2-bis(methanesulfonylmethyl) cyclohexane

To a suspension of irafts(R,R)-l,2-bis(hydroxymethyl)cyclohexane (15.0g) in dichloro methane (300 mL), triethyl amine (43.7 mL) followed by methane sulphonyl chloride (17.8 mL) were added over a period of 30-45 minutes. Reaction mass was stirred for 2-3 hrs. Reaction was monitored by HPLC (RI detector). After the completion of reaction, water was added, stirred and layers separated. The organic layer was washed with 10% sodium bicarbonate solution (150 mL) followed by water (150 mL). The dichloromethane was distilled off from organic layer under vacuum at 40-55 °C to give an oily mass. Methanol (30 mL) was added to the oily mass and strip off under vacuum at 40°C, added methanol (150 mL) and stirred for 1 h at 10-15°C and the solid obtained was filtered, washed with methanol (15 mL) and dried under vacuum to get the product (15.8g).

Example-6

Synthesis of ?ran (R,R)-3aJ(¾-octahvdroisoindolium-2-spiro- -r4-(L2-benzoisothiazole-3-yl)l piperazine methanesulfonate:

To a suspension of iran5(R,R)-l,2-bis(methanesulfonylmethyl)cyclohexane (15 g) in acetonitrile (150 mL) l-(l,2-benzisothiazol-3-yl)piperazine (10.95g) and sodium carbonate (7.8 g) were added, heated and stirred for 20 hrs at reflux temperature. Reaction was monitored by HPLC. After the completion of reaction, mass was cooled to 40-45 °C, filtered and washed with acetonitrile (20 mL). The acetonitrile was distilled off under vacuum at 45-50 °C. To the residue acetone (100 mL) was added, stirred for 1 hour, filtered, washed with acetone (10 mL), dried at 50-55°C for 6-8 hours to get the product (12.5 g).

Example-7

Synthesis of Lurasidone

To a suspension of iran5(R,R)-3<3,7(3-octahydroisoindolium-2-spiro- -[4-(l,2-benzo isothiazole-3-yl)]piperazinemethanesulfonate (10 g) in toluene (150 mL), bicycle[2.2.1] heptane-2-exo-3-exo-dicarboximide (5.9 g) and potassium carbonate (4.8 g) were added, heated to 110° C and stirred for 8-10 hours. Reaction was monitored by HPLC. After the completion of reaction, reaction mass was cooled to 20-30 °C, filtered and washed with toluene (10 mL). The toluene was distilled off at 55-60°C. To the residue IPA (100 mL) was added and stirred for 1-2 hours at room temperature. Lurasidone free base obtained was filtered and washed with IPA (10 mL). The solid was suck dried for 30 minutes to obtain lurasidone.

Example-8

Synthesis of Lurasidone hydrochloride

To lurasidone base (5g), acetone (75mL) and water (10 mL) were added. The mixture was heated to 55-60°C followed by the addition of IPA.HCl (10%) (lOmL) and stirred for 1-2 hours, reflux temperature. The clear solution obtained was stirred for 30 min and then 5ml IPA.HCl (10%) was added. The reaction mixture was stirred at reflux temperature for 30 min, cooled and stirred for 60 min. The solid obtained was filtered and washed with acetone (5ml) and dried under vacuum at 60°C for 8 hours.

Acetone: 542 ppm; IPA= 38ppm; Yield=93%

Example-9

Synthesis of Lurasidone hydrochloride

To lurasidone base (5g), acetone (75mL) and water (5 mL) were added. The mixture was heated to 55-60°C followed by the addition of IPA.HCl (10%) (5mL) and stirred for about 1-2 hours. The reaction mixture was stirred for 30 min. at 55-60°C, cooled and stirred for 60 min. The solid obtained was filtered and washed with acetone (5ml) and dried under vacuum at 70-80°C for 8 hours.

Jubilant Generics Limited

Pharmaceutical Company

Address: 18, 56, 57 and 58, KIADB Industrial Area, Nanjangud, Mysuru, Karnataka 571302

Chairman's Message

Chairman & Managing Director
Jubilant Bhartia Group Shyam, together with his brother Hari, is founder of Jubilant Bhartia Group (www.jubilantbhartia.com) headquartered in New Delhi, India. The Jubilant Bhartia Group, with 30,000 employees, has a strong presence in diverse sectors like Pharmaceuticals and Life Sciences, Oil and Gas (exploration and production), Agri products, Performance Polymers, Retail, Food and Consulting in Aerospace and Oilfield Services. Jubilant Bhartia Group has four flagships Companies- Jubilant Life Sciences Limited, Jubilant FoodWorks Limited and Jubilant Industries Limited, listed on Indian Stock Exchange and Jubilant Energy NV, listed at AIM market of London Exchange.Shyam, holds a bachelors’ degree in commerce from St. Xavier’s College, Calcutta University, and is a qualified cost and works accountant & a fellow member of the Institute of Cost and Works Accountants of India (ICWAI).Shyam has been associated with various institutions and has served as Member of Board of Governors, Indian Institute of Technology (IIT), Mumbai, and Indian Institute of Management (IIM), Ahmedabad. Shyam has also served as a Member of the Executive Committee of Federation of Indian Chamber of Commerce & Industry (FICCI) & Confederation of Indian Industry (CII) and was also a member of Task Force on Chemicals appointed by the Government of IndiaShyam’s immense contributions have been recognized by various awards. CHEMEXCIL has conferred Lifetime Achievement Award 2010-11 to him. He, along with his brother, was felicitated with the Entrepreneur of the Year Award at the prestigious AIMA Managing India Awards 2013, presented by the President of India. In 2010, the duo also shared the much-covetedErnst & Young Entrepreneur of the Year Award for Life Sciences & Consumer Products category.Shyam serves on the Board of several Public and Private and Foreign companies likes of Chambal Fertilizers and Chemicals Ltd, Putney Inc., CFCL Technologies Limited (Cayman Islands), Tower Promoters, BT Telecom India Pvt Ltd., American Orient Capital Partners India Pvt Ltd, IMACID, Morocco, Safe Food Corporation, etc. He was also a Director on the Board of Air India.Shyam is a regular participant at the World Economic Forum Annual Meeting in Davos and a member of the Chemical Governors Council of the World Economic Forum.Shyam is married to Shobhana, Former Member of Parliament & Chairperson, The Hindustan Times Media Ltd. They have two sons- Priyavrat and Shamit.

ISO Certification

ISO 9001:2008, 14001:2004 & OHSAS 18001:2007 certified

Code of Conduct

Code Of Conduct for Directors and Senior ManagementThis Code of Conduct highlights the standards of conduct expected from the Company’s Directors and Senior Management so as to align these with the Company’s Vision, Promise and Values.Jubilant Life Sciences Ltd. (Jubilant) has a well formulated Vision which drives the business and has the promise of Caring, Sharing, Growing to all the stakeholders–We will, with utmost care for the environment, continue to enhance value for our customers by providing innovative products and economically efficient solutions and for our shareholders through sales growth, cost effectiveness and wise investment of resources.

Director’s Desk

Co-Chairman & Managing Director
Jubilant Bhartia Group
Hari, together with his brother Shyam, is co-founder of Jubilant Bhartia Group (www.jubilantbhartia.com) headquartered in New Delhi, India.The Jubilant Bhartia Group, with 30,000 employees, has a strong presence in diverse sectors like Pharmaceuticals and Life Sciences, Oil and Gas (exploration and production), Agri products, Performance Polymers, Retail, Food and Consulting in Aerospace and Oilfield Services. Jubilant Bhartia Group has four flagships Companies- Jubilant Life Sciences Limited, Jubilant FoodWorksLimited and Jubilant Industries Limited, listed on Indian Stock Exchange and Jubilant Energy NV, listed at AIM market of London Exchange.A Chemical Engineering Graduate from the prestigious Indian Institute of Technology (IIT), Delhi, Hari was conferred the Distinguished Alumni award by his alma mater in 2000. He has been associated in various capacities with the IIT system and with the Ministry of Human Resource Development, Government of India.Hari is a past President of the Confederation of Indian Industry (CII) & a member of several educational, scientific and technological programmes of the Government of India. He is currently the Chairman of the Board of Governors of the Indian Institute of Management (IIM), Raipur and Member of the International Advisory Board of McGill University, Canada.Hari is the Co-Chairman of India-Canada CEO’s Forum appointed by the Prime Minister of India. He is also a member of CEO’s Forum for India-USA, India-France and India-Sri Lanka and Joint Task Force for India-Myanmar & India-UAE. He is a regular participant at the World Economic Forum Annual Meeting in Davos and is a member of the World Economic Forum’s International Business Council and the Health Governors.Hari’s immense contributions have been recognized by various awards. He, along with his brother, was felicitated with the Entrepreneur of the Year Award at the prestigious AIMA Managing India Awards 2013, presented by the President of India. In 2010, the duo also shared the much-coveted Ernst & Young Entrepreneur of the Year Award for Life Sciences & Consumer Products category.Hari serves on the board of several public and private companies like TV 18 Broadcast Ltd., Shriram Pistons & Rings Ltd., Export Credit Guarantee Corporation of India Ltd., BT Telecom India Pvt. Ltd & India Brand Equity Foundation.Hari is married to Kavita, a leading Fashion Designer and Retailer. They have a daughter, Aashti and a son, Arjun.

Executive Leadership Team

Shyam S Bhartia

Chairman
Hari S Bhartia

Co-Chairman & Managing Director
Shyamsundar Bang

Executive Director –Manufacturing & Supply Chain
R Sankaraiah

Executive Director – Finance
Pramod Yadav

Co-CEO
Life Science Ingredients
Rajesh Srivastava

Co-CEO
Life Science Ingredients
G. P. Singh

Fine Chemicals and CRAMS
CEO – Jubilant Pharma
Chandan Singh

President – Life Science Chemicals
Martyn Coombs

President – Jubilant DraxImage
Bryan Downey

President – Allergy Business
T. S. Parmar

President – India Branded Pharmaceuticals
Dr. Ashutosh Agarwal

Chief Scientific Officer –Chemicals and Life Science Ingredients
Ajay Khanna

Chief – Strategic & Public Affairs

read………http://www.jubl.com/uploads/downloads/93down_jll_sustainability_report_2014-15.pdf

///////Lurasidone hydrochloride, Jubilant Life Sciences Ltd, WO 2016059649, New patent

New Patent, Tedizolid phosphate, Suzhou MiracPharma Technology Co Ltd, Zheren Pharmaceutical Nanjing Co Ltd, WO 2016058467

PATENTS Comments Off

Apr 282016

Tedizolid phosphate

Suzhou MiracPharma Technology Co Ltd; Zheren Pharmaceutical Nanjing Co Ltd

WO-2016058467 click for patent

SUZHOU MIRACPHARMA TECHNOLOGY CO., LTD [CN/CN]; Room 1305, Building 1 Lianfeng Commercial Plaza, Industrial District Suzhou, Jiangsu 215000 (CN).
ZHEREN PHARMACEUTICAL NANJING CO., LTD [CN/CN]; Qiaolin Industry Park 32-71, Pukou District Nanjing, Jiangsu 211806 (CN)

Disclosed is a method for preparing tedizolid phosphate (I), and the preparation step thereof comprises producing the tedizolid phosphate (I) by means of a coupling reaction of a compound of formula II and a compound of formula III. The preparation method uses easily available raw materials and a simple process, is economical and environmentally friendly, and is suitable for industrial production.

Process for preparing tedizolid phosphate (TD-P), useful for treating bacterial infection. The present filing represents the first PCT and first filing to be seen from Suzhou Miracpharma and Zheren Pharmaceutical, respectively, that focuses on tedizolid; however this case was first seen as a Chinese national filing (assigned to Suzhou Miracpharma), published in February 2015. The drug was developed and launched by Dong-A ST and licensees Cubist Pharmaceuticals and Bayer, for treating acute bacterial skin and skin structure infections.

Tedizolid phosphate by Charpy Manchester (Cubist) pharmaceutical companies to develop a oxazolidinone antibiotics. Tedizolid phosphate in June 2014 to obtain FDA approval in the United States, the trade name Sivextro. The drug was first approved by the FDA in the second generation oxazolidinone antibiotics, and linezolid compared to the previous generation, Sivextro some bacteria in vitro inhibitory activity 2-8 times higher security to a certain extent also improved. Because compound Tedizolid not have standard Chinese translation, so the applicant where it is transliterated as “Thai to acetazolamide.”

Thailand phosphate to acetazolamide (Tedizolid phosphate) Chemical name: {(5R) -3- [3- fluoro-4- [6- (2-methyl–2H- tetrazol -5-yl) pyridine-3 yl] phenyl] -2-oxazolone -5-yl} methanol phosphate (I), having the formula:

Preparation of phosphate Thailand to acetazolamide has been reported, PCT Patent No. WO2005058886, No. WO2010042887 and “European Journal of Medicinal Chemistry” 2011 on 1027 – 1039 Section 46 were reported to temozolomide and phosphate Thai analog synthesis and related intermediates. Comparative summary of these methods, which are synthetic route from Intermediate A and Intermediate B (or intermediate B ‘) by an aryl coupling reaction to achieve.

Wherein 2- (2-methyl-tetrazol-5-yl) -5-bromopyridine (Intermediate A) is generated by a tetrazolium derivative azide reaction of 2-cyano-5-bromopyridine, and then the use of methyl iodide or dimethyl sulfate, etc. methylating reagent for tetrazole ring methylation reaction, to give 2- (2-methyl-tetrazol-5-yl) -5-bromopyridine (intermediate A ) and (1-methyl-tetrazol-5-yl) -5-bromo pyridine (by-product) in a mixture of 2, by column chromatography or recrystallization to give the intermediate separator A.

Intermediate B or B ‘by R-3- (3- fluoro-4-iodo-phenyl) -2-oxo-5-oxazolidinyl methanol formed organoboron reagent or an organotin reagent, the reagent is Stille or Suzuki coupling reactions, realize intermediate a coupling.

This shows that the existing preparation method has the steps for preparing long, difficult to obtain raw materials and high costs weaknesses; preparation and use of organotins on equipment and environmental requirements are high, there is environmental pollution risks. In addition, intermediate B or B ‘structure halogens fluorine and iodine exist, reducing the selective formation of organometallic reagents, so that an increase in side effects, product quality is difficult to be effectively controlled.

Example One:

Under a nitrogen atmosphere, in a three-necked reaction flask was added 2- (2-methyl-tetrazol-5-yl) pyridine-5-boronic acid (II) (2.15g, 10.5mmol) , R-3- (3- fluoro – 4-iodo – phenyl) -2-oxo-5-oxazolidinyl methanol phosphate (III) (4.17g, 10mmol) , tetrakis (triphenylphosphine) palladium (0.23g, 0.2mmol), 1M phosphoric acid 15mL of toluene solution of potassium 30mL, warmed to reflux, maintained the reaction at reflux for 10-12 hours, TLC the reaction was complete. Ethyl acetate was added 30mL, successively washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure, the resulting oil was treated with n-hexane and ethyl acetate (1:1, V / V) was recrystallized, and dried in vacuo to give a white The solid phosphoric acid to Thailand acetazolamide (I) 3.82g, yield% 84.9, ¹ the H NMR (of DMSO-d6): D 8.92 (S, IH), 8.20 (m, 2H), 7.74 (T, IH), 7.66 ( dd, 1H), 7.50 (dd , 1H), 4.95 (m, 1H), 4.46 (s, 3H), 4.21 (t, 1H), 4.05 (m, 2H), 3.91 (m, 1H), FAB-MS m / Z: 451 [the m the H +] ⁺ .

Example Two:

Under a nitrogen atmosphere, in a three-necked reaction flask was added 2- (2-methyl-tetrazol-5-yl) pyridine-5-boronic acid pinacol ester (II) (3.01g, 10.5mmol), R-3- (3 – fluoro-4-bromo – phenyl) -2-oxo-5-oxazolidinyl methanol phosphate (III) (3.69g, 10mmol), [1,1′- bis (diphenylphosphino) ferrocene Fe] dichloropalladium / dichloromethane complex (0.15g, 0.2mmol), potassium acetate (1.17g, 12mmol) and 1,4-dioxane 50mL, heated to 110 ℃, the reaction was stirred for 4-5 hours , TLC the reaction was complete. Ethyl acetate was added 50mL, successively washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure, the resulting oil was treated with n-hexane and ethyl acetate (1:1, V / V) was recrystallized, and dried in vacuo to give a white Thai solid phosphoric acid to acetazolamide (I) 4.02g, yield 89.3%.

Example Three:

Under a nitrogen atmosphere, in a three-necked reaction flask was added 2- (2-methyl-tetrazol-5-yl) -5-bromo – pyridine (IV) (2.4g, 10mmol), alcohol-based dual which diborane ( 1.27g, 5mmol), 1,1′- bis (diphenylphosphino) ferrocene palladium dichloride (0.82g, 1mmol), potassium acetate (1.17g, 12mmol) and 1,4-dioxane 30mL , heated to 110 deg.] C, the reaction was stirred for 4 hours. Cooled to room temperature, still under nitrogen, was added to the system for R-3- (3- fluoro-4-bromo – phenyl) -2-oxo-5-oxazolidinyl methanol phosphate (III) (3.69 g, 10mmol), 1,4- dioxane and 20mL 5M potassium phosphate 0.5mL, again heated to 100 ℃, the reaction was stirred for 4 hours, TLC the reaction was complete. Ethyl acetate was added 50mL, filtered and the filtrate was washed successively with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure, the resulting oil was treated with n-hexane and ethyl acetate (1:1, V / V) was recrystallized vacuo Thai dried to give a white solid phosphoric acid to acetazolamide (I) 3.34g, yield 74.2%.

IV (Preparation of the intermediate II) Example:

In a three-necked reaction flask 2- (2-methyl-tetrazol-5-yl) -5-bromo – pyridine (IV) (2.4g, 10mmol) was dissolved in 25mL anhydrous tetrahydrofuran, cooled to -55 deg.] C, was added dropwise isopropylmagnesium chloride (1M, 15ml), dropwise after completion of the reaction was stirred for 30 minutes. To the reaction system was added trimethylborate (1.25g, 12mmol), stirring was continued for 4-5 hours the reaction. At low temperature with saturated ammonium chloride solution to quench the reaction, and the reaction solution was poured into dilute hydrochloric acid and 30mL 1N reaction at room temperature for 1 hour. Extracted three times with ethyl acetate, the combined organic phase was washed with water and saturated brine, dried over anhydrous sodium sulfate. Concentrated under reduced pressure, the resulting solid is washed with petroleum ether, and then recrystallized from water to give a white solid of 2- (2-methyl-tetrazol-5-yl) pyridine-5-boronic acid (II) 1.6g, 78.0% yield, m the MS-FAB / Z: 206 [the m the H +] ⁺ .

Embodiment 5 (preparation of intermediate II):

In a three-necked reaction flask was added 2- (2-methyl-tetrazol-5-yl) -5-bromo – pyridine (IV) (2.4g, 10mmol) , alcohol-based dual which diborane (1.27g, 5mmol ), 1,1′-bis (diphenylphosphino) ferrocene palladium dichloride (0.82g, 1mmol), potassium acetate (1.17g, 12mmol) and 1,4-dioxane 50mL, heated to 110 ℃, the reaction was stirred for 8-10 hours to complete the reaction by TLC. Extracted three times with ethyl acetate, the combined organic phases were washed with brine, dried over anhydrous sodium sulfate. Concentrated, ethyl acetate and n-hexane (1:4) recrystallized to give an off-white solid 2- (2-methyl-tetrazol-5-yl) pyridine-5-boronic acid pinacol ester (II) 2.48g, yield 86.4 %, the MS-FAB m / Z: 288 [the m the H +] ⁺ .

Six (preparation of intermediate III) Example:

Under nitrogen, in a three-necked reaction flask R- glycidyl tosylate (TG) (2.28g, 10mmol) and N, N- dimethylformamide 25mL, stirred and dissolved, was added cesium carbonate (0.33 g, 1mmol) and 3-fluoro-4-bromo – phenyl isocyanate (V) (2.15g, 10mmol) , was heated to 100 ℃, after 1 hour, TLC detection completion of the reaction. Recovery of the solvent under reduced pressure, the residue was dissolved with dichloromethane and water, the organic phase was separated, the aqueous phase was extracted twice with methylene chloride, concentrated under reduced pressure to give an oil which was R-3- (3- fluoro-4-bromo – phenyl) -2-oxo-5-oxazolidinyl methanol p-toluenesulfonate (the VI), without further purification, 1N hydrochloric acid was added directly to the reaction at 50 ℃ 5 hours and extracted three times with dichloromethane The combined organic phase was successively washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The concentrate was dissolved in 30mL of triethyl phosphate was added at room temperature, phosphorus oxychloride (2.2mL, 24mmol), stirred for 2-3 hours. 30mL of ethyl acetate was added, stirred for half an hour, poured into 50g of ice-water, and stirring was continued for 2 hours at 0 deg.] C, and a solid white precipitate was filtered, the filter cake washed with acetone and dried to give an off-white solid R-3- (3-fluoro-4-bromo – phenyl) -2-oxo-5-oxazolidinyl methanol phosphate (III) 2.45g, yield 66.4%, FAB-MS m / z: 369 [m + H ] ⁺ .

Six (preparation of intermediate III) Example:

Under nitrogen, in a three-necked reaction flask R- glycidyl tosylate (TG) (2.28g, 10mmol) and tetrahydrofuran 50mL, stirred and dissolved, was added lithium iodide (0.14g, 1mmol) and 3- fluoro-4 – phenyl isocyanate (V) (2.63g, 10mmol) , was heated to reflux. after 2 hours, TLC detection completion of the reaction. Recovery of the solvent under reduced pressure, the residue was dissolved with dichloromethane and water, the organic phase was separated, the aqueous phase was extracted twice with methylene chloride, concentrated under reduced pressure to give an oil which was R-3- (3- fluoro-4 – phenyl) -2-oxo-5-oxazolidinyl methanol p-toluenesulfonate (the VI), without further purification, 1N hydrochloric acid was added directly to the reaction at 50 ℃ 5 hours and extracted three times with dichloromethane The combined organic phase was successively washed with water and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The concentrate was dissolved in 30mL of triethyl phosphate was added at room temperature, phosphorus oxychloride (2.2mL, 24mmol), stirred for 2-3 hours. 30mL of ethyl acetate was added, stirred for half an hour, poured into 50g of ice-water, and stirring was continued for 2 hours at 0 deg.] C, and a solid white precipitate was filtered, the filter cake washed with acetone and dried to give an off-white solid R-3- (3-fluoro-4-iodo – phenyl) -2-oxo-5-oxazolidinyl methanol phosphate (III) 2.65g, yield 63.7%, FAB-MS m / z: 417 [m + H ] ⁺ .

//////New Patent, Tedizolid phosphate, Suzhou MiracPharma Technology Co Ltd, Zheren Pharmaceutical Nanjing Co Ltd, WO 2016058467

NEW PATENT, WOCKHARDT LIMITED, WO 2016055918, ISAVUCONAZOLE

PATENTS Comments Off

Apr 222016

WO2016055918) NOVEL STABLE POLYMORPHS OF ISAVUCONAZOLE OR ITS SALT THEREOF

WOCKHARDT LIMITED [IN/IN]; D-4, MIDC Area, Chikalthana, Aurangabad 431006 (IN)

KHUNT, Rupesh Chhaganbhai; (IN).
RAFEEQ, Mohammad; (IN).
MERWADE, Arvind Yekanathsa; (IN).
DEO, Keshav; (IN)

The present invention relates to novel stable novel stable polymorphs of Isavuconazole or its salt thereof, having purity more than 90 % when measured by HPLC. In particular the present invention directs process for the preparation of solid amorphous and crystalline form of Isavuconazole base. In a further embodiment present invention directs to crystalline form Isavuconazole Hydrobromide salt and oxalate salt of 2-(2,5-difluoro- phenyl)-1-[1,2,4]triazol-1-yl-butane-2,3-diol.

Isavuconazole, Isavuconazonium, Voriconazole, and Ravuconazole are azole derivatives and known as antifungal drugs for treatment of systemic mycoses as reported in US 5,648,372, US 5,792,781, US 6,300,353 and US 6,812,238.

The US patent No. 6,300,353 discloses Isavuconazole and its process. It has chemical name [(2R,3R)-3-[4-(4-cyanophenyl)thiazol-2-yl)]-l -(lH-l,2,4-triazol-l-yl)-2-(2,5-difluorophenyl)43utan-2-ol; and has the structural formula I:

Formula I

The ‘353 described the process for the preparation Isavuconazole, involve the use of 2-(2,5-difluoro-phenyl)-l-[l ,2,4]triazol-l-yl-butane-2,3-diol (referred herein after “diol base”) in an oil form, which is difficult to isolate and purify. The use of 2-(2,5-difluoro-phenyl)-l-[l ,2,4]triazol-l-yl-butane-2,3-diol base, without purification, reflects the purity of Isavuconazole and Isavuconazonium sulfate. However, the reported process not feasible industrially.

Thus, an object of the present invention is to provide simple, cost effective and industrially feasible processes for preparation of Isavuconazole or its salt thereof in enhanced yield as well as purity. In a particular present invention directs to novel stable polymorphs of Isavuconazole or its salt thereof.

Examples

Example-1: Preparation of Amorphous Isavuconazole

In a round bottomed flask charged ethanol (250 ml), thioamide compound (25.0 gm) and 4-cyano phenacyl bromide (18.4 gm) under stirring. The reaction mixture were heated to 70 °C. After completion of reaction the solvent was removed under vacuum distillation and water (250 ml) and Ethyl acetate (350 ml) were added to reaction mass. The reaction mixture was stirred and its pH was adjusted between 7 to 7.5 by 10 % solution of sodium bicarbonate. The layer aqueous layer was discarded and organic layer was washed with saturated sodium chloride solution (100 ml) and concentrated under vacuum to get residue. The residue was suspended in methyl tert-butyl ether (250 ml) and the reaction mixture was heated to at 40°C to make crystals uniform and finally reaction mass is cooled to room temperature filtered and washed with the methyl tert-butyl ether. The product was isolated dried to get pale yellowish solid product.

Yield: 26.5 gm

HPLC purity: 92.7%

Example-2: Preparation of crystalline Isavuconazole Base

Charged methylene dichloride (250 ml) and 25.0 gm Isavuconazole Hydrobromide compound of formula-II into 1.0 L flask and stirred. Added aqueous solution of sodium bi carbonate in to the reaction mass to obtained clear solution. The layers were separated and organic layer was washed with dilute hydrochloric acid solution followed by saturated solution of sodium chloride. Finally, Organic layer was concentrated under vacuum to get titled product.

Yield: 18.5 gm

HPLC Purity: 97%

Example-3: Preparation of crystalline Isavuconazole Hydrobromide

Charged isopropanol alcohol (250 ml) followed by thioamide compound (25.0 gm) and 4-cyano phenacyl bromide (18.4 gm) into 1.0 L flask. The reaction mixture was stirred and heated to 50 C, after completion of reaction the precipitated material was filtered and washed with isopropanol alcohol (25 ml). The wet cake is dried under vacuum for 4-5 hrs at 40 C to obtain off-white solid product.

Yield: 26.5 gm

HPLC Purity: 97.3%

Exaniple-4: Synthesis of 2-(2,5-difluoro-phenyl)-l -[l,2,4]triazol-l-yl-butane-2,3-diol oxalate

Dissolved crude 50 gm 2-(2,5-difluoro-phenyl)-l-[l ,2,4]triazol-l -yl-butane-2,3-diol base compound in 150 ml of ethyl acetate. Oxalic acid dihydrate 25 gm was added into the reaction mixture and stirred. Heat the reaction mixture for 1 hour at 50-55 °C. The reaction mixture was cooled to 25°C to 35°C. Toluene 300 ml was added into the reaction mixture to precipitate the solid. The precipitate was washed with toluene and dried under vacuum to obtain the solid crystalline form of titled compound.

Yield: 58 g

HPLC Purity: 76%

Exaniple-5: Synthesis of 2-(2,5-difluoro-phenyl)-l -[l,2,4]triazol-l-yl-butane-2,3-diol oxalate salt

Exemplified procedure in example 1 with the replacement ethyl acetate solvent with tetrahydrofuran and antisolvent toluene with petroleum ether were used to get the title compound.

Exaniple-6: Synthesis of 2-(2,5-difluoro-phenyl)-l -[l,2,4]triazol-l-yl-butane-2,3-diol oxalate

Exemplified procedure in example 1 with the replacement ethyl acetate solvent with isopropyl acetate and antisolvent toluene with diisopropyl ether were used to get the title compound.

Exaniple-7: Synthesis of 2-(2,5-difluoro-phenyl)-l -[l,2,4]triazol-l-yl-butane-2,3-diol oxalate

Exemplified procedure in example 1 wherein diethyl ether is used in place of ethyl acetate and toluene or heptane was used as antisolvent to get the title compound.

Example-8: Synthesis of 2-(2,5-difluoro-phenyl)-l -[l,2,4]triazol-l-yl-butane-2,3-diol oxalate

Exemplified procedure in example 1 wherein diethyl ether is used in place of ethyl acetate and isolation of the product were done by means of partial removal of the solvent under vacuum.

Example-9: Synthesis of 2-(2,5-difluoro-phenyl)-l -[l,2,4]triazol-l-yl-butane-2,3-diol oxalate

Exemplified procedure in example 1 wherein ethyl acetate is replaced with isopropyl acetate and further, the reaction mass was stirred at lower temperatures to about 10°C to about 15°C for 3-5 hours and subsequently precipitated product was isolated and dried.

Example-10: Synthesis of 2-(2,5-difluoro-phenyl)-l-[l ,2,4]triazol-l-yl-butane-2,3-diol base

Stirring the suspension of 260 ml water and 65 gm 2-(2,5-difluoro-phenyl)-l-[l,2,4] triazol-l-yl-butane-2,3-diol oxalate salt were added. The reaction mixture pH was adjusted by addition of 10 % aqueous sodium carbonate solution. The pH was maintained to about pH 7 to about 8, 300 ml dichloro methane was added into the reaction mixture with stirring. The layers were separated and dichloromethane layer was collected. Aqueous layer was extracted with 150 ml dichloromethane. Dichloromethane layer was combined and washed with water. Dichloromethane was distilled out to get titled compound.

Yield: 35 gm

Purity: 87%