AMG 900, An aurora kinase (ARK) inhibitor potentially for the treatment of leukemia and solid tumours

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Jun 152016

AMG-900

N-(4-((3-(2-aminopyrimidin-4-yl)pyridin-2-yl)oxy)phenyl)-4-(4-methylthiophen-2-yl)phthalazin-1-amine.

N-(4-(3-(2-Aminopyrimidin-4-yl)pyridin-2-yloxy)phenyl)-4-(4-methylthiophen-2-yl)phthalazin-1-amine

Amgen Inc. INNOVATOR

Inventors	Victor J. Cee, Holly L. Deak, Bingfan Du,Stephanie D. Geuns-Meyer, Brian L. Hodous,Hanh Nho Nguyen, Philip R. Olivieri, Vinod F. Patel, Karina Romero, Laurie Schenkel,Less «
Applicant	Amgen Inc.

An aurora kinase (ARK) inhibitor potentially for the treatment of leukemia and solid tumours.

CAS No. 945595-80-2

In 2014, orphan drug designation was assigned in the U.S. for the treatment of ovarian cancer

Molecular Formula:	C₂₈H₂₁N₇OS
Molecular Weight:	503.57764 g/mo

	AMG 900; AMG-900; 945595-80-2; AMG900; UNII-9R2G075611; N-(4-((3-(2-aminopyrimidin-4-yl)pyridin-2-yl)oxy)phenyl)-4-(4-methylthiophen-2-yl)phthalazin-1-amine;

AMG 900 is a small-molecule inhibitor of Aurora kinases A, B and C with potential antineoplastic activity. Aurora kinase inhibitor AMG 900 selectively binds to and inhibits the activities of Aurora kinases A, B and C, which may result in inhibition of cellular division and proliferation in tumor cells that overexpress these kinases. Aurora kinases are serine-threonine kinases that play essential roles in mitotic checkpoint control during mitosis and are overexpressed by a wide variety of cancer cell types. Check for active clinical trials or closed clinical trials using this agent

AMG 900 is a potent and highly selective pan-Aurora kinases inhibitor for Aurora A/B/C with IC50 of 5 nM/4 nM /1 nM; >10-fold selective for Aurora kinases than p38α, Tyk2, JNK2, Met and Tie2.
IC50 Value: 5 nM(Aurora A); 4 nM(Aurora B); 1 nM(Aurora C)
Target: pan-Aurora
in vitro: AMG 900 is a novel class of ATP-competitive phthalazinamine small molecule inhibitors of aurora kinases. In HeLa cells, AMG 900 inhibits autophosphorylation of aurora-A and -B as well as phosphorylation of histone H3 on Ser, a proximal substrate of aurora-B. The predominant cellular response of tumor cells to AMG 900 treatment is aborted cell division without a prolonged mitotic arrest, which ultimately results in cell death. AMG 900 inhibits the proliferation of 26 tumor cell lines, including cell lines resistant to the antimitotic drug paclitaxel and to other aurora kinase inhibitors (AZD1152, MK-0457, and PHA-739358), at low nanomolar concentrations (about 2- 3 nM). Furthermore, AMG 900 is active in an AZD1152-resistant HCT116 variant cell line that harbors an aurora-B mutation (W221L) [1].
in vivo: Oral administration of AMG 900 blocks the phosphorylation of histone H3 in a dose-dependent manner and significantly inhibited the growth of HCT116 tumor xenografts. AMG 900 is broadly active in multiple xenograft models, including 3 multidrugresistant xenograft models, representing 5 tumor types [1]. AMG 900 exhibits a low-to-moderate clearance and a small volume of distribution. Its terminal elimination half-life ranged from 0.6 to 2.4 hours. AMG 900 is well-absorbed in fasted animals with an oral bioavailability of 31% to 107%. Food intake has an effect on rate (rats) or extent (dogs) of AMG 900 oral absorption. The clearance and volume of distribution at steady state in humans are predicted to be 27.3 mL/h/kg and 93.9 mL/kg, respectively. AMG 900 exhibits acceptable PK properties in preclinical species and is predicted to have low clearance in humans [2].

In mammalian cells, the aurora kinases (aurora-A, -B, and -C) play essential roles in regulating cell division. The expression of aurora-A and -B is elevated in a variety of human cancers and is associated with high proliferation rates and poor prognosis, making them attractive targets for anticancer therapy. AMG 900 is an orally bioavailable, potent, and highly selective pan-aurora kinase inhibitor that is active in taxane-resistant tumor cell lines. In tumor cells, AMG 900 inhibited autophosphorylation of aurora-A and -B as well as phosphorylation of histone H3 on Ser(10), a proximal substrate of aurora-B. The predominant cellular response of tumor cells to AMG 900 treatment was aborted cell division without a prolonged mitotic arrest, which ultimately resulted in cell death. AMG 900 inhibited the proliferation of 26 tumor cell lines, including cell lines resistant to the antimitotic drug paclitaxel and to other aurora kinase inhibitors (AZD1152, MK-0457, and PHA-739358), at low nanomolar concentrations. Furthermore, AMG 900 was active in an AZD1152-resistant HCT116 variant cell line that harbors an aurora-B mutation (W221L). Oral administration of AMG 900 blocked the phosphorylation of histone H3 in a dose-dependent manner and significantly inhibited the growth of HCT116 tumor xenografts. Importantly, AMG 900 was broadly active in multiple xenograft models, including 3 multidrug-resistant xenograft models, representing 5 tumor types. AMG 900 has entered clinical evaluation in adult patients with advanced cancers and has the potential to treat tumors refractory to anticancer drugs such as the taxanes.

MG 900 is an orally bioavailable, potent, and highly selective pan-aurora kinase inhibitor that is active in taxane-resistant tumor cell lines. In tumor cells, AMG 900 inhibited autophosphorylation of aurora-A and -B as well as phosphorylation of histone H3 on Ser10, a proximal substrate of aurora-B. The predominant cellular response of tumor cells to AMG 900 treatment was aborted cell division without a prolonged mitotic arrest, which ultimately resulted in cell death. AMG 900 inhibited the proliferation of 26 tumor cell lines, including cell lines resistant to the antimitotic drug paclitaxel and to other aurora kinase inhibitors (AZD1152, MK-0457, and PHA-739358), at low nanomolar concentrations. Furthermore, AMG 900 was active in an AZD1152-resistant HCT116 variant cell line that harbors an aurora-B mutation (W221L). Oral administration of AMG 900 blocked the phosphorylation of histone H3 in a dose-dependent manner and significantly inhibited the growth of HCT116 tumor xenografts. Importantly, AMG 900 was broadly active in multiple xenograft models, including 3 multidrug-resistant xenograft models, representing 5 tumor types. AMG 900 has entered clinical evaluation in adult patients with advanced cancers and has the potential to treat tumors refractory to anticancer drugs such as the taxanes. (Source: Cancer Res; 70(23); 9846Â–54.)

Clinical Information of AMG 900

Product Name	Sponsor Only	Condition	Start Date	End Date	Phase	Last Change Date
AMG 900	Amgen Inc	Leukemia	31-JUL-11	31-JUL-14	Phase 1	14-SEP-13
AMG 900	Amgen Inc	Advanced solid tumor	30-APR-09	30-JUN-13	Phase 1	10-SEP-13

AMG 900.png

PATENT

WO 2007087276

http://www.google.co.in/patents/WO2007087276A1?cl=en

PATENT

WO 2015084649

https://google.com/patents/WO2015084649A1?cl=en

The compound, N-(4-((3-(2-amino-4-pyrimidinyl)-2-pyridinyl)oxy)phenyl)- 4-(4-methyl-2-thienyl)-l-phthalazinamine, also chemically named as 4-((3-(2-amino- pyrimidin-4-yl)-pyridin-2-yl)oxy)phenyl-(4-(4-methyl-thiophen-2-yl)-phthalazin-l- yl)amine, and is referred to herein as “AMG 900” has a chemical structure of

AMG 900 is an ATP competitive small molecule Aurora kinase inhibitor that is highly potent and selective for Aurora kinases A, B and C. AMG 900 is disclosed in US patent publication no. 20070185111, which published on August 9, 2007 and issued as U.S. Patent No. 7,560,551. AMG 900 is further disclosed in US patent publication no.

20090163501, now US patent no 8,022,221. Various uses and applications of AMG 900 are described in patent publications US20120028917 and WO2013149026. AMG 900 is being clinically evaluated primarily for its safety, tolerability and pharmacokinetic (PK) profile in human phase I trials for (1) advanced solid tumors (US Clinical Trial Id No. NCT00858377), and (2) for acute leukemias (US Clinical Trial Id No. NCT1380756).

Different solid state forms of a given compound are typically investigated to determine whether or not a particular form possesses and/or exhibits desirable properties allowing that compound to be clinically and/or commercially developed. Such beneficial and advantageous properties, by way of example, include without limitation, crystallinity, improved thermodynamic stability, non-hygroscopicity, high purity, minimal to total absence of moisture and/or residual solvents, chemical stability, high yielding synthetic process and/or manufacturability and reproducibility, desirable biopharmaceutical properties including improved dissolution characteristics and increased bioavailability, absence or reduced toxicities due to reduced or limited exposure, rate of exposure or release, or related to counter ions, good bulk and formulation properties including good flow, bulk density, desirable particle size and the like, or a combination of the aforementioned characteristic attributes.

Generally when a compound, also referred to herein as drug substance (DS), has been identified as a developmental candidate, the DS is screened to identify potentially beneficial polymorphic, crystalline or solid state forms of the compound and/or a pharmaceutically acceptable salt thereof. X-ray diffraction, Raman, solid state NMR and a melting point temperature and/or a melting point temperature range have been typically used to monitor or screen and identify the different polymorphic form of the DS.

Different polymorphic forms of a given DS can have an impact on that compound’s solubility, stability and bioavailability. Also, it is important to monitor possible changes in polymorphic forms of the DS during stability studies.

AMG 900 was previously isolated and identified as a free base compound. This compound exhibited rather lack-luster pharmacokinetic (PK) and/or pharmacodynamic (PD) properties, including poor aqueous solubility, poor bioavailability, poor absorption, poor target exposure and overall, a not-so-attractive in-vivo efficacy profile. Thus, there is a need to address and solve the technical problem of identifying alternative forms of AMG 900 to achieve substantially the same effect or an improved effect, including improved PK and PD profiles, as that of AMG 900 known in the art.

Example 1

Synthesis of N-(4-((3-(2-amino-4-pyrimidinyl^N)-2-pyridinyl^N)oxy^N)phenyl^N)-4-(4-methyl-2-thienvD-l-phthalazinamine (AMG 900)

Step 1 : 4-(2-chloropyridin-3-yl)pyrimidin-2 -amine

In an argon purged 500 mL round bottom flask placed in an isopropanol bath, was added sodium metal (3.40g, 148mmol) slowly to methanol (180mL). The mixture was stirred at room temperature (RT) for about 30 minutes. To this was added guanidine hydrochloride (12.0 mL, 182 mmol) and the mixture was stirred at RT for 30 minutes, followed by addition of (E)-l-(2-chloropyridin-3-yl)-3-(dimethylamino)prop-2-en-l-one (12.0 g, 57.0 mmol), attached air condenser, moved reaction to an oil bath, where it was heated to about 50 °C for 24 hr. Approximately half of the methanol was evaporated under reduced pressure and the solids were filtered under vacuum, then washed with saturated sodium bicarbonate (NaHCO and H^O, air dried to yield 4-(2-chloropyridin-3-yl)pyrimidin-2-amine as off white solid. MS m/z = 207 [M+l]⁺. Calc’d for C₉H₇C1N₄: 206.63.

Step 2: 4-(2-(4-aminophenoxy)pyridin-3-yl)pyrimidin-2-amine

To a resealable tube was added 4-aminophenol (1.3 g, 12 mmol), cesium carbonate (7.8 g, 24 mmol), and DMSO (16 ml, 0.75 M). The mixture was heated to 100 °C for 5 minutes, and then 4-(2-chloropyridin-3-yl)pyrimidin-2 -amine (2.5 g, 12 mmol) was added, and the reaction mixture was heated to 130 °C overnight. Upon completion, as judged by LCMS, the reaction mixture was allowed to cool to RT and diluted with water. The resulting precipitate was filtered, and the solid washed with water and diethyl ether. The solid was then taken up in 9: 1 CH₂Cl₂:MeOH and passed through a pad of silica gel with 9:1 CH₂Cl₂:MeOH as eluent. The solvent was concentrated in vacuo to provide the desired product, 4-(2-(4-aminophenoxy)pyridin-3-yl)pyrimidin-2-amine. MS m/z = 280

[M+l]⁺. Calc’d for Ci₅H₁₃N₅0: 279.30.

Step 3: l-Chloro-4-(4-methylthiophen-2-yl)phthalazine

1 ,4-Dichlorophthalazine (1.40 g, 7.03 mmol), 4-methyltmophen-2-ylboronic acid (999 mg, 7.03 mmol), and PdCl₂(DPPF) (721 mg, 985 μιηοΐ) were added into a sealed tube. The tube was purged with Argon. Then sodium carbonate (2.0 M in water) (7.74 ml, 15.5 mmol) and 1,4-dioxane (35.2 ml, 7.03 mmol) were added. The tube was sealed, stirred at RT for 5 min, and placed in a preheated oil bath at 110 °C. After 1 hr, LC-MS showed product and byproduct (double coupling), and starting material

dichlorophthalazme. The reaction was cooled to RT, filtered through a pad of celite with an aid of ethyl acetate (EtOAc), concentrated, and loaded onto column. The product was purified by column chromatography using Hex to remove the top spot, then 80:20 hexanes:EtOAc to collect the product. The product, 1 -chloro-4-(4-methylthiophen-2-yl)phthalazine was obtained as yellow solid. LC-MS showed that the product was contaminated with a small amount of dichlorophthalazme and biscoupling byproduct. MS m/z = 261 [M+l]⁺. Calcd for Ci₃H₉ClN₂S: 260.12.

Step 4: N-(4-((3-(2-amino-4-pyrimidinyl)-2-pyridinyl)oxy)phenyl)-4-(4-methyl-2-thienyl)- 1 -phthalazinamine

To 4-(2-(4-aminophenoxy)pyridin-3-yl)pyrimidin-2 -amine and l-chloro-4-(4-methyl-2-thienyl)phthalazine was added tBuOH. The resulting mixture was heated at 100 °C in a sealed tube for 16 hours. The rection was diluted with diethyl ether and saturated sodium carbonate and vigorously shaken. The resulting solids were filtered and washed with water, diethyl ether and air dried to yield N-(4-((3-(2-amino-4-pyrimidinyl)-2-pyridinyl)oxy)phenyl)-4-(4-methyl-2-thienyl)-l -phthalazinamine as an off-white solid. MS m/z = 504 [M+H]⁺. Calc’d for C₂₈ H₂₁ N₇ O S: 503.58.

Example 2

Alternative Synthesis of N-(4-((3-(2-amino-4-pyrimidinyl^N)-2-pyridinyl^N)oxy^N)phenyl^N)-4-(4-methyl-2-thienvD-l-phthalazinamine (AMG 900)

Step 1 : 4-(2-chloropyridin-3-yl)pyrimidin-2 -amine

Step 2: 4-(2-(4-aminophenoxy)pyridin-3-yl)pyrimidin-2-amine

To a reaction vessel at ambient temperature was added 4-aminophenol (571 g, 5.25 mol, 1.05 equiv) followed by 4-(2-chloropyridin-3-yl)pyrimidin-2-amine (1064g, 97 wt%, 5.00 mol, 1.0 equiv) and DMSO (7110 ml, 7820 g, 7x the volume of 4-(2-chloropyridin-3-yl)pyrimidin-2 -amine). The reaction mixture was agitated and sparged with nitrogen gas for at least 10 minutes. Then a 50 weight % aqueous KOH solution (593 g, 5.25 mol, 1.05 equiv.) was added to the mixture while keeping the reaction

mixture temperature below about 40°C. The mixture was sparged with nitrogen gas for more than 5 minutes, the sparging tube was removed, and the reaction mixture was heated to 110 +/- 10 °C for at least 1.5 hrs. Upon completion, as judged by HPLC, the reaction mixture was allowed to cool to RT and diluted with 6N HC1 (42 mL, 0.25 mol, 0.05 equiv). The desired product, 4-(2-(4-aminophenoxy)pyridin-3-yl)pyrimidin-2 -amine was not isolated. Rather, it was formed in-situ and combined with the product of step 3 below, in step 4 to form the desired product.

Step 3: l-Chloro-4-(4-methylthiophen-2-yl)phthalazine

A separate reaction vessel was fitted with a reflux condenser and an addition funnel, and 4-(4-methylthiophen-2-yl)phthalazin-l(2H)-one (1,537 mg, 6.34 mol, 1.0 equivalent) was added to the reaction vessel. Acetonitrile (7540 mL, 5859 g, 5 V), was added and the reaction vessel was agitated to allow the starting material to dissolve. The vessel was then charged with phosphorus oxychloride (709 ml, 1166 g, 7.44 mol, 1.2 equivalents) and the reaction was heated to about 75 +/- 5 °C for a least 4 hrs. The reaction was cooled to about about 25 +/- 5 °C and held there for more than 24 hrs. N,N-diisopropylethylamine (3046 g, 4100 mL, 3.8 equivalents) was added to the reaction vessel and the temperature was maintained at <30°C. Pyridine (97g, 1.24 mol, 0.2 equiv) was added in a single portion followed by water (4100 g, 2.7V) over more than 30 minutes. The reaction mixture was stirred at ambient temperature ofr about 24 hrs. the mixture was filtered through a <25uM polypropylene filter and the rsulting mother liquor was diluted with 1 : 1 ACN:water (9000 mL total) and stirred for a minimum of 2 minutes. Filter off product solids as they precipitate. Collect mother liquor and washes to obtain additional product. Dry the filter cake, and additional product crops, under a constant stream of nitrogen gas for at least 14 hrs. Unlike the previous method, the present method avoids contamination of impurities, such as dichlorophthalazine and biscoupling byproduct, as seen via LC-MS. Yield: 1537 g (97.2 weight %). MS m/z = 261 [M+l]⁺. Calcd for Ci₃H₉ClN₂S: 260.12.

Step 4: N-(4-((3-(2-amino-4-pyrimidinyl)-2-pyridinyl)oxy)phenyl)-4-(4-methyl-2-thienyl)- 1 -phthalazinamine

To the reaction mixture was added l-chloro-4(4-methylthiophen-2-yl)phthalazine

(1450g, 97.2 wt%, 5.40 mol, 1.08 equiv) rinding the addition port with DMSO (520 ml, 572 g, 0.5x the volume of 4-(2-chloropyridin-3-yl)pyrimidin-2-amine). The reaction mixture was again agitated and sparged with nitrogen gas for at least 10 minutes. The sparging tube was removed, and the reaction mixture was heated to 80 +/- 20 °C for at least 2 hrs. Upon completion, as judged by HPLC, the reaction mixture was allowed to cool to RT and N,N-diisopropylethylamine (776 g, 1045 mL, 6.0 mol, 1.2 equiv) was added and the mixture was kept at about 80 +/- 10°C. Filter the mixture at about 80oC into a separate reactor vessel rinsing with DMSO (1030 mL, 1133 g, 1 V). Then adjust the raction mixture temperature to about 70+/-5 °C and add 2-propanol (13200 mL, 10360 g, 12.75 V) over more than 15 minutes at about 70°C. As the reaction mistreu cools, the product begins to precipitate out of solution. Add more 2-propanol (8780 mL, 6900 g, 8.5V) to the solution slowly over more then 60 minutes at about 70°C. The reactor vessel was cooled to about 20°C over more than 60 minutes and let sit for over 2 hrs. The product was filtered through an Aurora filter with a >25uM polypropylene filter cloth. Additional crops were obtained from the mother liquors by diluting with additional 2-propanol. The filter cakes were dried under a constant stream of nitrogen gas for at least 14 hrs to provide the desired product, N-(4-((3-(2-amino-4-pyrimidinyl)-2-pyridinyl)oxy)phenyl)-4-(4-methyl-2-thienyl)-l-phthalazinamine as an off-white solid. Yield: 2831 g (88.8%); purity 99.7%. MS m/z = 504 [M+H]⁺. Calc’d for C₂₈ H₂₁ N₇ O S: 503.58.

The starting material 1 used/shown in Example 2 was prepared as follows:

and starting material 3, thienyl substituted phthalazinone, shown in Example 2 was prepared as follows:

Starting material 3

Synthesis of 4-(5-methylthiophen-2-yl)phthalazin-l(2//)-one

Step 1 : 2-(Dimethylamino)isoindoline-1.3-dione

A solution of isobenzofuran-l,3-dione (5.00 g, 34 mmol) and N,N-dimethylhydrazine (2.9 ml, 37 mmol) in toluene (75 ml, 34 mmol) was added p-TsOH H₂0 (0.32 g, 1.7 mmol). The Dean-Stark apparatus and a condenser were attached. The mixture was refluxed. After 4 hr, LCMS showed mainly product. The reaction was cooled to rt. Toluene was removed under reduced pressure the crude was dissolved in DCM, washed with sat NaHC0₃, water, and brine. The organic was dried over MgS0₄, filtered, and concentrated. Light yellow solid was obtained. ^!H NMR showed mainly product, 2-(dimethylamino)isoindoline-l,3-dione. MS Calcd for C10H10N2O2: [M]⁺ = 190. Found: [M+H]⁺ = 191.

Step 2 : 2-(Dimethylamino)-3 -hydroxy-3 -(5 -methylthiophen-2 -vDisoindolin- 1 -one

A solution of 2-bromo-5-methylthiophene (0.60 mL, 5.3 mmol) in THF (11 mL) was purged with nitrogen and cooled to -78 °C. «-Butyllithium (2.2 mL, 5.5 mmol; 2.5 M in THF) was added and the mixture was stirred under nitrogen for 30 min. This solution was cannulated into a flask containing a solution of 2-(dimethylamino)isoindoline-l,3-dione (1.5 g, 7.9 mmol) in THF (16 mL) at -78 °C under nitrogen. The reaction was allowed to warm to -30 °C over an hour, at which point LCMS showed complete conversion of 2-bromo-5-methylthiophene to product. The reaction was quenched by careful addition of saturated aqueous NH₄C1. The reaction mixture was diluted with dichloromethane and water, and the layers were separated. The aqueous portion was extracted with additional dichloromethane, and the combined organic layers were dried with MgS0₄, filtered, concentrated, and purified by silica gel chromatography eluting with 0-2% MeOH in dichloromethane to provide intermediate A, as a light yellow solid, 2-(dimethylamino)-3-hydroxy-3-(5-methylthiophen-2-yl)isoindolin-l-one (1.2 g, 80% yield). ^!H NMR (400 MHz, DMSO-4) δ 7.68-7.65 (m, 1H). 7.63-7.59 (m, 1H), 7.57-7.51 (m, 1H), 7.37 (d, 1H, J=8), 7.09 (s, 1H), 6.69-6.66 (m, 1H), 6.65-6.62 (m, 1H), 2.81 (s, 6H), 2.40 (s, 3H). ¹³C NMR (400 MHz, DMSO-de) δ 165.0, 147.3, 141.6, 139.3, 132.7, 129.49, 129.46, 125.0, 124.7, 123.0, 122.1, 88.4, 44.7, 14.9. FT-IR (thin film, cm ) 3347, 3215, 1673. MS Calcd for Ci₂H₇ClN₂S: [M]⁺ = 288. Found: [M+H]⁺= 289.

HRMS Calcd for Ci₅H₁₆N₂0₂S: [M+H]⁺= 288.1005, [M+Na]⁺ = 311.0825. Found:

[M+H]⁺ = 289.1022, [M+Na]⁺= 311.0838. mp = 138-140 °C.

Step 3: 4-(5-Methylthiophen-2-yl)phthalazin-l(2//)-one

2-(Dimethylamino)-3 -hydroxy-3 -(5 -methylthiophen-2-yl)isoindolin- 1 -one (1.1 g, 0.40 mmol), EtOH (4.0 mL), and hydrazine (0.19 mL, 59 mmol) were added into a RBF fitted with a reflux condenser. A nitrogen balloon was attached on top of the condenser. After refluxing overnight, the reaction was cooled to room temperature. An off-white solid precipitated. After cooling to 0 °C, water was added. The solid was filtered off with an aid of water and dried under vacuum to afford a white solid, 4-(5-methylthiophen-2-yl)phthalazin-l(2//)-one (0.82 g, 85% yield).

^!H NMR (400 MHz, CDC1₃) δ 10.57 (s, 1H), 8.50-8.39 (m, 1H), 8.14-8.04 (m, 1H), 7.83- 7.69 (m, 2H), 7.20-7.17 (m, 1H), 6.82-6.71 (m, 1H), 2.47 (s, 3H). ¹³C NMR (400 MHz,

CDC1₃) 8 159.9, 142.5, 141.1, 134.3, 133.7, 131.7, 129.4, 128.8, 128.3, 127.1, 126.6,

125.8, 15.4. FT-IR (thin film, cm^“1) 2891, 1660, 1334. MS Calcd for Ci₃H₁₀N₂OS: [M]⁺

= 242. Found: [M+H]⁺= 243. HRMS Calcd for Ci₃H₁₀N₂OS: [M+H]⁺= 243.0587. Found:

[M+H]⁺ = 243.0581. mp = 191-194 °C.

Alternatively, starting material 3 was prepared as follows:

The above scheme depicts the process by which intermediate-scale synthesis of thiophene-phthalazinone 5 (shown above) was prepared. Treatment of 50 grams of 3-methylthiophene with z^‘-PrMgCl at 66 °C in the presence of catalytic TMP-H resulted in 98% conversion to the reactive species lb with a >40:1 regioisomeric ratio. After cooling to 20 °C, this mixture was added dropwise to a -20 °C slurry of phthalic anhydride in THF to provide keto acid 3 in 94% assay yield. While this intermediate could be crystallized from toluene/heptane, the crude reaction mixture was taken directly in a through -process conversion to the phthalazinone 5. To that end, removal of THF, MTBE, and residual 3-methylthiophene was accomplished through a distillative solvent switch into ethanol. The resulting solution of 3 was exposed to aqueous hydrazine at 80 °C. After 18 hours, the reaction was cooled and the precipitated product was filtered directly at 20 °C. This process provided 82.7 grams of 98.6 wt % thiophene-phthalazinone 5 in a weight-adjusted 85% yield over the two steps.

LCMS Method:

Samples were run on a Agilent model- 1100 LC-MSD system with an Agilent Technologies XDB-C₈ (3.5 μ) reverse phase column (4.6 x 75 mm) at 30 °C. The flow rate was constant and ranged from about 0.75 mL/min to about 1.0 mL/min.

The mobile phase used a mixture of solvent A (H₂O/0.1% HO Ac) and solvent B

(AcCN/O.1 HOAc) with a 9 min time period for a gradient from 10%> to 90%> solvent B. The gradient was followed by a 0.5 min period to return to 10% solvent B and a 2.5 min 10% solvent B re-equilibration (flush) of the column.

Other methods may also be used to synthesize AMG 900. Many synthetic chemistry transformations, as well as protecting group methodologies, useful in synthesizing AMG 900, are known in the art. Useful organic chemical transformation literature includes, for example, R. Larock, Comprehensive Organic Transformations, VCH Publishers (1989); T.W. Greene and P.G.M. Wuts, Protective Groups in Organic Synthesis, 3^rd edition, John Wiley and Sons (1999); L. Fieser and M. Fieser, Fieser and Fieser’s Reagents for Organic Synthesis, John Wiley and Sons (1994); A. Katritzky and

A. Pozharski, Handbook of Heterocyclic Chemistry, 2^nd edition (2001); M. Bodanszky, A. Bodanszky, The Practice of Peptide Synthesis, Springer- Verlag, Berlin Heidelberg (1984); J. Seyden-Penne, Reductions by the Alumino- and Borohydrides in Organic Synthesis, 2^nd edition, Wiley- VCH, (1997); and L. Paquette, editor, Encyclopedia of Reagents for Organic Synthesis, John Wiley and Sons (1995).

AMG 900 was tested for its ability to reduce or inhibit tumor progression in various cell lines (in-vitro) and multiple solid tumor types (in-vivo), some of which have previously been exposed to and developed resistance to standard-of-care antimitotic agents, including taxanes and vinca alkaloids, as well as to other chemotherapeutic agents. The following Examples and resulting data will illustrate the ability of AMG 900 to treat cancer, including cancer resistant to the presently standard-of-care therapies, including antimitotic agents, such as paclitaxel, and other drugs used in conjunction with chemotherapy, such as doxorubicin. Unless otherwise indicated, the free base form of AMG 900 was used in the Examples described hereinbelow.

The following Examples describe the efforts of identifying and characterizing various crystalline solid state forms of various salts of AMG 900. Some attempts at forming a solid state crystalline form of a given salt failed, as shown in table 1 hereinbelow. To this end, synthesizing and/or forming &isolating a crystalline solid state form of AMG 900 was not, in any way, straightforward or routine. Rather, the ability to prepare and identify a crystalline solid state form of AMG 900 depended upon the particular salt of AMG 900 and/or the crystallization conditions employed.

PAPER

Journal of Medicinal Chemistry (2015), 58(13), 5189-5207

Discovery of N-(4-(3-(2-Aminopyrimidin-4-yl)pyridin-2-yloxy)phenyl)-4-(4-methylthiophen-2-yl)phthalazin-1-amine (AMG 900), A Highly Selective, Orally Bioavailable Inhibitor of Aurora Kinases with Activity against Multidrug-Resistant Cancer Cell Lines

^†Departments of Medicinal Chemistry, ^‡Pharmaceutical Research and Development, ^§Pharmacokinetics and Drug Metabolism, ^∥Molecular Structure, and ^⊥Oncology Research, Amgen Inc., 360 Binney Street, Cambridge, Massachusetts 02142, United States, and Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States

J. Med. Chem., 2015, 58 (13), pp 5189–5207

DOI: 10.1021/acs.jmedchem.5b00183

*Phone: 617-444-5041. E-mail: MeyerS@amgen.com.

http://pubs.acs.org/doi/abs/10.1021/acs.jmedchem.5b00183

ACS Editors’ Choice – This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.

Abstract

Efforts to improve upon the physical properties and metabolic stability of Aurora kinase inhibitor14a revealed that potency against multidrug-resistant cell lines was compromised by increased polarity. Despite its high in vitro metabolic intrinsic clearance, 23r (AMG 900) showed acceptable pharmacokinetic properties and robust pharmacodynamic activity. Projecting from in vitro data to in vivo target coverage was not practical due to disjunctions between enzyme and cell data, complex and apparently contradictory indicators of binding kinetics, and unmeasurable free fraction in plasma. In contrast, it was straightforward to relate pharmacokinetics to pharmacodynamics and efficacy by following the time above a threshold concentration. On the basis of its oral route of administration, a selectivity profile that favors Aurora-driven pharmacology and its activity against multidrug-resistant cell lines, 23r was identified as a potential best-in-class Aurora kinase inhibitor. In phase 1 dose expansion studies with G-CSF support, 23r has shown promising single agent activity.

N-(4-(3-(2-Aminopyrimidin-4-yl)pyridin-2-yloxy)phenyl)-4-(4-methylthiophen-2-yl)phthalazin-1-amine (23r)

Applying similar SNAr conditions as for 23b, reaction of 22r and 20a in 2-butanol provided the title compound (2.08 g, 49%) as an off-white solid; mp (DSC) 216 °C.

¹H NMR (400 MHz, DMSO-d₆) δ ppm 9.36 (s, 1 H) 8.64–8.69 (m, 1 H) 8.41–8.44 (m, 1 H) 8.36–8.40 (m, 1 H) 8.35 (d, J = 5.2 Hz, 1 H) 8.23 (dd, J = 4.8, 2.0 Hz, 1 H) 8.00–8.10 (m, 2 H) 7.91–7.97 (m, 2 H) 7.52 (d, J = 1.0 Hz, 1 H) 7.26–7.33 (m, 3 H) 7.16–7.22 (m, 2 H) 6.74 (br s, 2 H) 2.34 (br s, 3 H).

¹³C NMR (150 MHz, DMSO-d₆) δ 163.81, 160.72, 160.67, 158.68, 151.64, 148.50, 148.36, 147.14, 139.86, 139.24, 137.72, 137.10, 132.61, 131.74, 130.24, 125.27, 124.89, 122.92, 122.83, 122.44, 121.56, 121.52, 119.11, 118.23, 109.93, 15.6

HRMS m/z [M + H]⁺ Calcd for C₂₈H₂₁N₇OS: 504.1601. Found: 504.1607.

Table 1. Aurora Kinase Inhibitors with Known Structures That Have Entered Clinical Trials

http://pubs.acs.org/doi/full/10.1021/acs.jmedchem.5b00183

ID, compd name	AK^a	AK cell assay^b	(nM)	most potently inhibited non-AKs (nM)^c [total kinases in panel]	admin route
1 (MK-0457/VX-680/tozasertib)(7)	A/B	MDA-MB-231 p-HH3(12)	43	FLT3 (6), PLK4 (9), ABL (13), MLCK (15), RET (28); [317](16)	IV
2 (PHA-739358/danusertib)(8)	A/B	MDA-MB-231 p-HH3(12)	49	ABL (25), RET (31), TrkA (31), FGFR1 (47); [35](17)	IV
3a(AZD1152/barasertib)^d^,(9)	B	MDA-MB-231 p-HH3(12)	16	FLT3 (8), cKIT (17), PDGFRA (38), PDGFRB (41), RET (80); [317](16)	IV
4 (AT9283)(18)	A/B	HCT-116 DNA ploidy	∼30	JAK2 (1), JAK3 (1) Abl (T315I) (4), 9 others ≤10 nM; [230]	IV
5 (SNS-314)(19)	A/B	HCT-116 DNA ploidy(20)	9	TrkB (5), TrkA (12), FLT4 (14), Fms (15), DDR2 (82), Axl (84); [219]	IV
6 (GSK1070916)(21)	B	HCT-116 p-HH3(22)	20	FLT1 (42), TIE2 (59), SIK (70), FLT4 (74), FGFR (78); [328](22)	IV
7 (ENMD-2076)(23)	A	HCT-116 p-AurA	130	FLT3 (2), RET (10), FLT4 (16), SRC (20), TrkA (24), Fms (25); [100]	PO
8 (CYC116)(24)	A/B	A549 p-HH3	480	VEGFR2 (44), FLT3 (44), CDK2 (390); [23]	PO
9 (ABT-348)(25)	A/B	HCT-116 p-HH3	21	VEGFR1 (1), FLT3 (1), VEGFR2 (2), CSF-1R (3), PDGFR-α (11); [128]	PO
10 (AS703569/R763)(26)	A/B	A549 p-HH3	14	cell-based assays: VEGFR2 (11), FLT3 (27), AMPK (201); [10]	PO
11 (PF-03814735)(27)	A/B	MDA-MB-231 p-HH3	∼50	FLT1 (10), FAK (22), TrkA (30), 17 others ≥90% inh@100 nM; [220]	PO
12 (MK-5108)(28)	A	HeLa S3 ↑p-HH3+ cells	<1000	TrkA (2), ABL (8), FLT4 (12), TrkB (13), VEGFR2 (30); [233]	PO
13a (MLN8054)(29)	A	HCT-116 p-AurA	34	DRAK2 (8), BLK (68), DRAK1 (190), FGR (220); [317](16)	PO
13b (MLN8237/alisertib)(30)	A	HeLa p-AurA	7	%inh@1 μM: EphA2 (111), FGR (97), CAMK2A (95), EphA4 (94); [220]	PO

AK = Aurora kinase family member(s) inhibited (AurA and/or AurB; AurC potency not listed).

Cell line; substrate or phenotype detected.

Kinase activities of greatest potency listed in published literature.

Listed enzyme and cellular potency data is for 3b, the parent of prodrug 3a.

References on AMG 900

[1]. Payton M, et al. Preclinical evaluation of AMG 900, a novel potent and highly selective pan-aurora kinase inhibitor with activity in taxane-resistant tumor cell lines. Cancer Res, 2010, 70(23), 9846-9854.

[2]. Huang L, et al. In vitro and in vivo pharmacokinetic characterizations of AMG 900, an orally bioavailable small molecule inhibitor of aurora kinases. Xenobiotica. 2011 May;41(5):400-8.

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///////////945595-80-2, AMG 900, aurora kinase (ARK) inhibitor, treatment of leukemia and solid tumours, AMGEN, 2014, orphan drug designation, U.S. for the treatment of ovarian cancer

CC1=CSC(=C1)C2=NN=C(C3=CC=CC=C32)NC4=CC=C(C=C4)OC5=C(C=CC=N5)C6=NC(=NC=C6)N

Pexidartinib

orphan status, Phase 3 drug, Uncategorized Comments Off

Jun 102016

Pexidartinib

PLX-3397

5-((5-chloro-1H-pyrrolo[2,3-b]pyridin-3-yl)methyl)-N-((6-(trifluoromethyl)pyridin-3-yl)methyl)pyridin-2-amine

N-[5-[(5-Chloro-1H-pyrrolo[2,3-b]pyridin-3-yl)methyl]-2-pyridinyl]-6-(trifluoromethyl)-3-pyridinemethanamine

A Multi-targeted tyrosine kinase inhibitor potentially for the treatment of tenosynovial giant cell tumor (TGCT).


CAS No.:	1029044-16-3
Mol. Formula:	C20H15ClF3N5
Mol. Weight:	417.81

Pexidartinib; 1029044-16-3; PLX-3397; 5-((5-chloro-1H-pyrrolo[2,3-b]pyridin-3-yl)methyl)-N-((6-(trifluoromethyl)pyridin-3-yl)methyl)pyridin-2-amine; 5-[(5-chloro-1H-pyrrolo[2,3-b]pyridin-3-yl)methyl]-N-[[6-(trifluoromethyl)pyridin-3-yl]methyl]pyridin-2-amine; 5-[(5-Chloro-1h-Pyrrolo[2,3-B]pyridin-3-Yl)methyl]-N-{[6-(Trifluoromethyl)pyridin-3-Yl]methyl}pyridin-2-Amine;
Originator Plexxikon
Developer Barbara Ann Karmanos Cancer Institute; Columbia University; Merck & Co; National Cancer Institute (USA); Plexxikon; University of California at San Francisco
Class 2 ring heterocyclic compounds; Antineoplastics; Fluorine compounds; Pyridines; Pyrroles; Small molecules
Mechanism of Action Fms-like tyrosine kinase 3 inhibitors; Immunomodulators; Macrophage colony stimulating factor receptor antagonists; Proto oncogene protein c-akt inhibitors; Proto oncogene protein c-kit inhibitors

Orphan Drug Status Yes – Giant cell tumour of tendon sheath; Pigmented villonodular synovitis

Phase III Pigmented villonodular synovitis
Phase II Glioblastoma; Malignant melanoma; Prostate cancer
Phase I/II Breast cancer; Leukaemia; Peripheral nervous system diseases; Sarcoma; Solid tumours
Phase I Gastrointestinal stromal tumours
No development reported Neurological disorders; Rheumatoid arthritis
Discontinued Acute myeloid leukaemia; Hodgkin’s disease

Most Recent Events

25 May 2016 Plexxikon and AstraZeneca plan the MEDIPLEX phase I trial for Solid tumours (Combination therapy, Metastatic disease) in France (NCT02777710)
05 Apr 2016 Daiichi Sankyo plans a phase I trial for Solid tumours (Late-stage disease, Second-line therapy or greater) in Taiwan (PO) (NCT02734433)
11 Mar 2016 Plexxikon re-initiates enrolment in a phase Ib trial in Solid tumours and Gastrointestinal stromal tumours in USA (NCT02401815)

Multi-targeted receptor tyrosine kinase inhibitor of CSF1R, c-Kit, and FLT3 (IC50 values 13 nM, 27 nM, and 11 nM, respectively) Administration of PLX3397 reduced CIBP, induced substantial intratumoral fibrosis, and was also highly efficacious in reducing tumor cell growth, formation of new tumor colonies in bone, and pathological tumor-induced bone remodeling. PLX3397 is superior to imatinib in the treatment of malignant peripheral nerve sheath tumor (MPNST), and the combination of PLX3397 with a TORC1 inhibitor could provide a new therapeutic approach for the treatment of this disease.

Plexxikon is conducting phase III clinical studies with PLX-3397 for the treatment of pigmented villonodular synovitis. Phase II clinical studies are ongoing for the oral treatment of melanoma and glioblastoma multiforme. Additional early clinical trials are underway for the treatment of metastatic breast cancer, for the treatment of prostate cancer (adenocarcinoma), and for the treatment of malignant peripheral nerve sheath tumor. No recent development has been reported from preclinical studies for the treatment of systemic lupus erythematosus and for the treatment of multiple sclerosis. Prior to patient enrollment, a phase I clinical trial by Plexxikon for the treatment of rheumatoid arthritis was withdrawn. Daiichi Sankyo (parent of Plexxikon) decided to discontinue phase II trials of the product for the treatment of castration-resistant prostate cancer and for the treatment of Hodgkin’s lymphoma after reviewing its clinical study results and also have discontinued phase II studies for the treatment of acute myeloid leukemia due to strategic reasons.

In 2014, orphan drug designation was assigned to the compound in the US for the treatment of pigmented villonodular synovitis andf giant cell tumor of the tendon sheath. In 2015, the compound was granted orphan designation in the E.U. for the treatment of tenosynovial giant cell tumor, localised and diffuse type. In the same year, the product was granted breakthrough therapy designation for the treatment of tenosynovial giant cell tumor (TGCT) where surgical removal of the tumor would be associated with potentially worsening functional limitation or severe morbidity.

C-fms and c-kit arc both type III transmembrane receptor protein tyrosine kinases (RPTKs) that regulate key signal transduction cascades that control cellular growth and proliferation. Both receptors have similar structural features comprising five extracellular immunoglobulin (IG) domains, a single transmembrane domain, and a split cytoplasmic kinase domain separated by a kinase insert segment.

c-Fms
C-fms is a member of the family of genes originally isolated from the Susan McDonough strain ot teline sarcoma viruses, The cellular proto-oncogene FMS (c-fms, cellular feline McDonough sarcoma) codes for the receptor for the macrophage colony-stimuktmg tactor (M- CSF) C-fms is crucial for the growth and differentiation of the monocyte-macrophage lineage, and upon binding of Vf-CSF to the extracellular domain of c-fms, the receptor dimeπzes and trans- autophosphorylates cytoplasmic tyrosine residues

M-CSF, first described by Robinson and co-workers (Blood 1969, 33 396-9), is a cytokine that controls the production, differentiation, and function of macrophages M-CSF stimulates differentiation of progenitor cells to mature monocytes, and prolongs the survival of monocytes Furthermore, M-CSF enhances cytotoxicity, superoxide production, phagocytosis, chemota\is, and secondary cytokine production of additional factors in monocytes and macrophages Examples of such additional factors include granulocyte colony stimulating lactor (G-CSF) interleukin-6 (IL-6), and mterleukm-8 (IL-8) M-CSF stimulates hematopoiesis, promotes differentiation and proliferation of osteoclast progenitor cells, and has profound effects on lipid metabolism Furthermore, M-CSF is important in pregnancy Physiologically, large amounts of M-CSF are produced in the placenta, and M-CSF is believed to play an essential role in trophoblast differentiation (Motoyoshi, lnt J Hematol 1998, 67 109-22) l hc elevated semm levels of M-CSF m early pregnancy may participate in the immunologic mechanisms responsible for the maintenance of the pregnancy (Flanagan & Lader, Curr Opm Hematol 1998, 5 181-5)

Related to c-fms and c-kit are two p_latelet -derived growth factor receptors, alpha (i e , pdgfra) and beta (pdgfrb) (PDGF) 1 he gene coding for pdgfra is located on chromosome 4ql 1 -q!2 in the same region of chromosome 4 as the oncogene coding for c-kit The genes coding for pdgfra and c-fms appear to have evolved from a common ancestral gene by gene duplication, inasmuch as these two genes are tandemly linked on chromosome 5 They are oriented head to tail with the 5-pnme exon of the c-fms gene located only 500 bp from the last 3-pπme exon of the gene coding for pdgfra Most gastrointestinal stromal tumors (GIST) have activating mutations in c-kit and most patients with GISTs respond well to Gleevec, which inhibits c-kit Hemπch et al (Science 2003, 299 “OS-IO) have shown that approximately 35% of GISTs lacking c-krt mutations, have intragenic activation mutations m tht gene encoding pdgfra, and that tumors expressing c-kit or pdgfrd are indistinguishable with respect to activation of downstream signaling intermediates and cytogenetic changes associated with tumor progression Thus, c kit and pdgfra mutations appear to be alternative and mutually exclusive oncogenic mechanisms m GISTs [0007} Similarly, the observation that production of M-CSF, the major macrophage growth factor, is increased in tissues during inflammation points out a role for c-frns in diseases, such as for example inflammatory diseases. More particularly, because elevated levels of M-CSF are found in the disease state, modulation of the activity of c-fms can ameliorate disease associated with increased levels of M-CSF.

c-Kit
The Stem Cell Factor (SCF) receptor c-kit plays an important role in the development of melanocytes and mast, germ and hematopoietic cells. Stem Cell Factor (SCF) is a protein encoded by the Sl locus, and has also been called “kit ligand” (KL) and mast cell growth factor (MGF), based on the biological properties used to identify it (reviewed in Tsujimura, Pathol Int 1996, 46:933-938; Loveland, et al., J. Endocrinol 1997, 153:337-344; Vliagoftis, et al,, Clin Immunol 1997, 100:435-440; Broudy, Blood 1997, 90: 1345-1364; Pignon, Hermatol Cell Ther 1997, 39: 1 14-1 16; and Lyman, et al., Blood 1998, 91 : 1 101 -1 134.). Herein the abbreviation SCF refers to the physiological ligand for c-kit.

SCF is synthesized as a transmembrane protein with a molecular weight of 220 or 248 Dalton, depending on alternative splicing of the mRNA to encode exon 6. The larger protein can be proteolytically cleaved to form, a soluble, glycosylated protein which noncovalently dimerizcs. Both the soluble and membrane-bound forms of SCF can bind to and activate c-kit. For example, in the skin, SCF is predominantly expressed by fibroblasts, keratinocytes, and endothelial cells, which modulate the activity of melanocytes and mast cells expressing c-kit. In bone, marrow stromal cells express SCF and regulate hematopoiesis of c-kit expressing stem cells. In the gastrointestinal tract, intestinal epithelial cells express SCF and affect the interstitial cells of Cajal and intraepithelial lymphocytes. In the testis, Sertoli cells and granulosa cells express SCF which regulates spermatogenesis by interaction with c-kit on germ cells.

PATENT

WO 2008063888

PATENT

WO 2008064265

PATENT

WO 2008064255

PATENT

WO 2012158957

Fragments in the clinic: PLX3397

Practical Fragments covers a wide variety of journals. J. Med. Chem., Bioorg. Med. Chem. Lett., Drug Disc. Today, and ACS Med. Chem. Lett. are all well-represented, but we also range further afield, from biggies such asNature and Science to more niche titles such as ChemMedChem, Acta. Cryst. D., and Anal. Chim. Acta. The increasingly clinical relevance of fragment-based approaches is highlighted by a recent paper by William Tap and a large group of collaborators appearing in the New England Journal of Medicine. This reports on the results of the Daiichi Sankyo (née Plexxikon) drug PLX3397 in a phase I trial for tenosynovial giant-cell tumor, a rare but aggressive cancer of the tendon sheath.

The story actually starts with a 2013 paper by Chao Zhang and his Plexxikon colleagues in Proc. Nat. Acad. Sci. USA. The researchers were interested in inhibiting the enzymes CSF1R (or FMS) and KIT; both kinases are implicated in cancer as well as inflammatory diseases. The team started with 7-azaindole, the same fragment they used to discover vemurafenib. Structural studies of an early derivative, PLX070, revealed a hydrogen bond between the ligand oxygen and a conserved backbone amide. Further building led to PLX647, with good activity against both CSF1R and KIT. Selectivity profiling against a panel of 400 kinases revealed only two others with IC₅₀values < 0.3 µM. The molecule was active in cell-based assays, had good pharmacokinetics in mice and rats, and was active in rodent models of inflammatory disease.

The new paper focuses on the results of a clinical trial with PLX3397, a derivative of PLX647. Despite its close structural similarity to PLX647, it binds to CSF1R in a slightly different manner. Both inhibitors bind to the inactive form of the kinase, but PLX3397 also recruits the so-called juxtamembrane domain of the kinase to stabilize this autoinhibited conformation. Pharmacokinetic and pharmacodynamics studies in animals were also positive.

http://practicalfragments.blogspot.in/2015/10/fragments-in-clinic-plx3397.html

Tenosynovial giant-cell tumor seems to be dependent on CSF1R, so the researchers performed a phase 1 dose-escalation study with an extension in which patients treated with the chosen phase 2 dose were treated longer. Of the 23 patients in this extension, 12 had a partial response and 7 had stable disease. A quick search ofclinicaltrials.gov reveals that PLX3397 is currently in multiple trials for several indications, including a phase 3 trial for giant cell tumor of the tendon sheath.

Several lessons can be drawn from these studies. First, as the authors note, one fragment can give rise to multiple different clinical candidates. Indeed, in addition to vemurafenib, 7-azaindole was also the starting point forAZD5363. This is a good counterargument to those who believe that novelty is essential in fragments.

A second, related point is that selectivity is also not necessary for a fragment. The fact that 7-azaindole comes up so frequently as a kinase-binding fragment has not prevented researchers from growing it into remarkably selective inhibitors. An obvious corollary is that even subtle changes to a molecule can have dramatic effects: the added pyridyl nitrogen in PLX3397 is essential for stabilizing a unique conformation of the enzyme.

Patent ID	Date	Patent Title
US2015265586	2015-09-24	COMPOUNDS MODULATING C-FMS AND/OR C-KIT ACTIVITY AND USES THEREFOR
US2014243365	2014-08-28	COMPOUNDS MODULATING C-FMS AND/OR C-KIT ACTIVITY AND USES THEREFOR
US8722702	2014-05-13	Compounds modulating c-fms and/or c-kit activity and uses therefor
US2014045840	2014-02-13	COMPOUNDS AND METHODS FOR KINASE MODULATION, AND INDICATIONS THEREFOR
US2013274259	2013-10-17	KINASE MODULATION AND INDICATIONS THEREFOR
US8404700	2013-03-26	Compounds modulating c-fms and/or c-kit activity and uses therefor
US2011230482	2011-09-22	COMPOUNDS MODULATING C-FMS AND/OR C-KIT ACTIVITY
US7893075	2011-02-22	Compounds modulating c-fms and/or c-kit activity and uses therefor

//////1029044-16-3, Pexidartinib , PLX-3397, PHASE3

FC(F)(F)c1ccc(cn1)CNc2ccc(cn2)Cc4cnc3ncc(Cl)cc34

Start of the Euro 2016

INCB24360 (epacadostat)

phase 2, Uncategorized Comments Off

Apr 182016

Epacadostat

(Z)-N-(3-bromo-4-fluorophenyl)-N’-hydroxy-4-[2-(sulfamoylamino)ethylamino]-1,2,5-oxadiazole-3-carboxamidine

1,2,5-Oxadiazole-3-carboximidamide, 4-[[2-[(aminosulfonyl)amino]ethyl]amino]-N-(3-bromo-4-fluorophenyl)-N’-hydroxy-

1204669-58-8

INCB024360

N-(3-Brom-4-fluorphenyl)-N’-hydroxy-4-{[2-(sulfamoylamino)ethyl]amino}-1,2,5-oxadiazol-3-carboximidamid

UNII 71596A9R13

(Z)-N-(3-bromo-4-fluorophenyl)-N’-hydroxy-4-(2-(sulfamoylamino)ethylamino)-1,2,5-oxadiazole-3-carboximidamide

1,2,5-Oxadiazole-3-carboximidamide, 4-[[2-[(aminosulfonyl)amino]ethyl]amino]-N’-(3-bromo-4-fluorophenyl)-N-hydroxy-

Molecular Formula, C₁₁H₁₃BrFN₇O₄S

Average mass438.233 Da

cas 1204669-58-8 (or 1204669-37-3)

Synonym:	IDO1 inhibitor INCB024360 indoleamine-2,3-dioxygenase inhibitor INCB024360
Code name:	INCB 024360 INCB024360
Chemical structure:	1,2,5-Oxadiazole-3-carboximidamide, 4-((2-((Aminosulfonyl)amino)ethyl)amino)-N-(3-bromo-4-fluorophenyl)-N’-hydroxy-, (C(Z))-

Company	Incyte Corp.
Description	Indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor
Molecular Target	Indoleamine 2,3-dioxygenase 1 (IDO1)
Mechanism of Action	Indoleamine 2,3-dioxygenase (INDO) inhibitor
Therapeutic Modality	Small molecule

OriginatorIncyte Corporation
DeveloperFred Hutchinson Cancer Research Center; Incyte Corporation; Merck AG
ClassAmides; Antineoplastics; Imides; Oxadiazoles; Small molecules
- Phase IIFallopian tube cancer; Malignant melanoma; Non-small cell lung cancer; Ovarian cancer; Peritoneal cancer; Solid tumours
Most Recent Events
- 15 Jan 2016Phase-II clinical trials in Solid tumours (Combination therapy, Late-stage disease, Second-line therapy or greater) in USA (PO)
- 11 Jan 2016Phase-II clinical trials in Non-small cell lung cancer (Combination therapy, Late-stage disease, Second-line therapy or greater) in USA (PO)
- 11 Jan 2016The US FDA and Health Canada approve IND application and Clinical Trial Application, respectively, for a phase Ib trial in Ovarian cancer (Combination therapy, Recurrent, Second-line therapy or greater)

In 2016, orphan drug designation was assigned to the compound in the US. for the treatment of stage IIB-IV melanoma

EpacadostatAn orally available hydroxyamidine and inhibitor of indoleamine 2,3-dioxygenase (IDO1), with potential immunomodulating and antineoplastic activities. epacadostat targets and binds to IDO1, an enzyme responsible for the oxidation of tryptophan into kynurenine. By inhibiting IDO1 and decreasing kynurenine in tumor cells, epacadostat increases and restores the proliferation and activation of various immune cells, including dendritic cells (DCs), NK cells, and T-lymphocytes, as well as interferon (IFN) production, and a reduction in tumor-associated regulatory T cells (Tregs). Activation of the immune system, which is suppressed in many cancers, may inhibit the growth of IDO1-expressing tumor cells. IDO1 is overexpressed by a variety of tumor cell types and DCsINCB24360 (epacadostat), An Agent For Cancer Immunotherapy

Incyte and Merck Expand Clinical Collaboration to Include Phase 3 Study Investigating the Combination of Epacadostat with Keytruda® (pembrolizumab) as First-line Treatment for Advanced Melanoma

Pivotal study to evaluate Incyte’s IDO1 inhibitor in combination with Merck’s anti-PD-1 therapy in patients with advanced or metastatic melanoma

WILMINGTON, Del. and KENILWORTH, N.J. — October 13, 2015 — Incyte Corporation (Nasdaq: INCY) and Merck (NYSE:MRK), known as MSD outside the United States and Canada, today announced the expansion of the companies’ ongoing clinical collaboration to include a Phase 3 study evaluating the combination of epacadostat, Incyte’s investigational selective IDO1 inhibitor, with Keytruda® (pembrolizumab), Merck’s anti-PD-1 therapy, as first-line treatment for patients with advanced or metastatic melanoma. The Phase 3 study, which is expected to begin in the first half of 2016, will be co-funded by Incyte and Merck.

“We are very pleased to expand our collaboration with Merck and to move the clinical development program for epacadostat in combination with Keytruda into Phase 3,” said Hervé Hoppenot, President and Chief Executive Officer of Incyte. “We believe the combination of these two immunotherapies shows promise and, if successfully developed, may help to improve clinical outcomes for patients with metastatic melanoma.”

“The initiation of this large Phase 3 study with Incyte in the first-line advanced melanoma treatment setting is an important addition to our robust immunotherapy clinical development program for Keytruda,” said Dr. Roger Dansey, senior vice president and therapeutic area head, oncology late-stage development, Merck Research Laboratories. “We continue to explore the benefit that Keytruda brings to patients suffering from advanced melanoma when used alone, and we are pleased to be able to add this important combination study with epacadostat to our Keytruda development program.”

Under the terms of the agreement Incyte and Merck have also agreed, for a period of two years, not to initiate new pivotal studies of an IDO1 inhibitor in combination with a PD-1/PD-L1 antagonist as first-line therapy in advanced or metastatic melanoma with any third party. During this time, the companies will each offer the other the opportunity to collaborate on any new pivotal study involving an IDO1 inhibitor in combination with a PD-1/PD-L1 antagonist for types of melanoma and lines of therapy outside of the current collaboration agreement.

The agreement is between Incyte and certain subsidiaries and Merck through its subsidiaries.

Epacadostat and Keytruda are part of a class of cancer treatments known as immunotherapies that are designed to enhance the body’s own defenses in fighting cancer; the two therapies target distinct regulatory components of the immune system. IDO1 is an immunosuppressive enzyme that has been shown to induce regulatory T cell generation and activation, and allow tumors to escape immune surveillance. Keytruda is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2. Preclinical evidence suggests that the combination of these two agents may lead to an enhanced anti-tumor immune response compared with either agent alone.

Safety and efficacy data from the ongoing Phase 1/2 study evaluating the combination of epacadostat with Keytruda in patients with advanced malignancies is scheduled to be highlighted as a late-breaking oral presentation (Abstract #142) at the upcoming Society for Immunotherapy of Cancer 30th Anniversary Annual Meeting & Associated Programs, November 4–8, 2015 at the Gaylord National Resort & Convention Center in National Harbor, MD.

Metastatic Melanoma

Melanoma, the most serious form of skin cancer, strikes adults of all ages and accounts for approximately five percent of all new cases of cancer in the United States each year. The number of new cases of melanoma continues to rise by almost three percent each year which translates to 76,000 new cases yearly in the U.S. alone.[i] The 5-year survival rate for late-stage or metastatic disease is 15 percent.[ii]

About Epacadostat (INCB024360)

Indoleamine 2,3-dioxygenase 1 (IDO1) is an immunosuppressive enzyme that has been shown to induce regulatory T cell generation and activation, and allow tumors to escape immune surveillance. Epacadostat is an orally bioavailable small molecule inhibitor of IDO1 that has nanomolar potency in both biochemical and cellular assays and has demonstrated potent activity in enhancing T lymphocyte, dendritic cell and natural killer cell responses in vitro, with a high degree of selectivity. Epacadostat has shown proof-of-concept clinical data in patients with unresectable or metastatic melanoma in combination with the CTLA-4 inhibitor ipilimumab, and is currently in four proof-of-concept clinical trials with PD-1 and PD-L1 immune checkpoint inhibitors in a variety of cancer histologies.

PATENT

WO 2014066834

https://www.google.com/patents/WO2014066834A1?cl=en

EXAMPLE 1

4-({2-[(Aminosulfonyl)amino]ethyl}amino)- V-(3-bromo-4-fluorophenyl)- V -hydroxy- l,2,5-oxadiazole-3-carboximidamide

Step 1: 4-Amino-N’-hydroxy-l,2,5-oxadiazole-3-carboximidamide

[00184] Malononitrile (320.5 g, 5 mol) was added to water (7 L) preheated to 45 °C and stirred for 5 min. The resulting solution was cooled in an ice bath and sodium nitrite (380 g, 5.5 mol) was added. When the temperature reached 10 °C, 6 N hydrochloric acid (55 mL) was added. A mild exothermic reaction ensued with the temperature reaching 16 °C. After 15 min the cold bath was removed and the reaction mixture was stirred for 1.5 hrs at 16-18 °C. The reaction mixture was cooled to 13 °C and 50% aqueous hydroxylamine (990 g, 15 mol) was added all at once. The temperature rose to 26 °C. When the exothermic reaction subsided the cold bath was removed and stirring was continued for 1 hr at 26-27 °C, then it was slowly brought to reflux. Reflux was maintained for 2 hrs and then the reaction mixture was allowed to cool overnight. The reaction mixture was stirred in an ice bath and 6 N hydrochloric acid (800 mL) was added in portions over 40 min to pH 7.0. Stirring was continued in the ice bath at 5 °C. The precipitate was collected by filtration, washed well with water and dried in a vacuum oven (50 °C) to give the desired product (644 g, 90%). LCMS for C3H6N5O2

(M+H)+: m/z = 144.0. ¹³C MR (75 MHz, CD3OD): δ 156.0, 145.9, 141.3. Step 2: 4-Amino-N-hydroxy-l,2,5-oxadiazole-3-carboximidoyl chloride [00185] 4-Amino-N^,-hydroxy-l ,2,5-oxadiazole-3-carboximidamide (422 g, 2.95 mol) was added to a mixture of water (5.9 L), acetic acid (3 L) and 6 Ν hydrochloric acid (1.475 L, 3 eq.) and this suspension was stirred at 42 – 45 °C until complete solution was achieved. Sodium chloride (518 g, 3 eq.) was added and this solution was stirred in an ice/water/methanol bath. A solution of sodium nitrite (199.5 g, 0.98 eq.) in water (700 mL) was added over 3.5 hrs while maintaining the temperature below 0 °C. After complete addition stirring was continued in the ice bath for 1.5 hrs and then the reaction mixture was allowed to warm to 15 °C. The precipitate was collected by filtration, washed well with water, taken in ethyl acetate (3.4 L), treated with anhydrous sodium sulfate (500 g) and stirred for 1 hr. This suspension was filtered through sodium sulfate (200 g) and the filtrate was concentrated on a rotary evaporator. The residue was dissolved in methyl i-butyl ether (5.5 L), treated with charcoal (40 g), stirred for 40 min and filtered through Celite. The solvent was removed in a rotary evaporator and the resulting product was dried in a vacuum oven (45 °C) to give the desired product (256 g, 53.4%). LCMS for C3H4CIN4O2 (M+H)+: m/z = 162.9. ¹³C NMR (100 MHz, CD3OD): 5 155.8, 143.4, 129.7.

Step 3: 4-Amino-N’-hydroxy-N-(2-methoxyethyl)-l,2,5-oxadiazole-3-carboximidamide [00186] 4-Amino-N-hydroxy-l ,2,5-oxadiazole-3-carboximidoyl chloride (200.0 g, 1.23 mol) was mixed with ethyl acetate (1.2 L). At 0-5 °C 2-methoxyethylamine [Aldrich, product # 143693] (119.0 mL, 1.35 mol) was added in one portion while stirring. The reaction temperature rose to 41 °C. The reaction was cooled to 0 – 5 °C. Triethylamine (258 mL, 1.84 mol) was added. After stirring 5 min, LCMS indicated reaction completion. The reaction solution was washed with water (500 mL) and brine (500 mL), dried over sodium sulfate, and concentrated to give the desired product (294 g, 1 19%) as a crude dark oil.

LCMS for C₆Hi_{2 5}0₃ (M+H)⁺: m/z = 202.3. 1H NMR (400 MHz, DMSO- ): δ 10.65 (s, 1 H), 6.27 (s, 2 H), 6.10 (t, J = 6.5 Hz, 1 H), 3.50 (m, 2 H), 3.35 (d, J = 5.8 Hz, 2 H), 3.08 (s, 3 H).

Step 4: N’-Hydroxy-4-[(2-methoxyethyl)amino]-l,2,5-oxadiazole-3-carboximidamide

[00187] 4-Amino-N-hydroxy-N-(2-methoxyethyl)-l,2,5-oxadiazole-3- carboximidamide (248.0 g, 1.23 mol) was mixed with water (1 L). Potassium hydroxide (210 g, 3.7 mol) was added. The reaction was refluxed at 100 °C overnight (15 hours). TLC with 50% ethyl acetate (containing 1% ammonium hydroxide) in hexane indicated reaction completed (product Rf = 0.6, starting material Rf = 0.5). LCMS also indicated reaction completion. The reaction was cooled to room temperature and extracted with ethyl acetate (3 x 1 L). The combined ethyl acetate solution was dried over sodium sulfate and concentrated to give the desired product (201 g, 81%) as a crude off-white solid. LCMS for C6H12N5O3 (M+H)⁺: m/z = 202.3 ^LH NMR (400 MHz, OMSO-d₆): δ 10.54 (s, 1 H), 6.22 (s, 2 H), 6.15 (t, J = 5.8 Hz, 1 H), 3.45 (t, J= 5.3 Hz, 2 H), 3.35 (m, 2 H), 3.22 (s, 3 H). Step 5: N-Hydroxy-4-[(2-methoxyethyl)amino]-l,2,5-oxadiazole-3-carboximidoyl chloride

[00188] At room temperature N’-hydroxy-4-[(2-methoxyethyl)amino]- 1 ,2,5- oxadiazole-3-carboximidamide (50.0 g, 0.226 mol) was dissolved in 6.0 M hydrochloric acid aqueous solution (250 mL, 1.5 mol). Sodium chloride (39.5 g, 0.676 mol) was added followed by water (250 mL) and ethyl acetate (250 mL). At 3-5 °C a previously prepared aqueous solution (100 mL) of sodium nitrite (15.0 g, 0.217 mol) was added slowly over 1 hr. The reaction was stirred at 3 – 8 °C for 2 hours and then room temperature over the weekend. LCMS indicated reaction completed. The reaction solution was extracted with ethyl acetate (2 x 200 mL). The combined ethyl acetate solution was dried over sodium sulfate and concentrated to give the desired product (49.9 g, 126%) as a crude white solid. LCMS for

C₆HioClN₄03 (M+H)⁺: m/z = 221.0. ^!H NMR (400 MHz, DMSO-d₆): δ 13.43 (s, 1 H), 5.85 (t, J= 5.6 Hz, 1 H), 3.50 (t, J= 5.6 Hz, 2 H), 3.37(dd, J= 10.8, 5.6 Hz, 2 H), 3.25 (s, 3 H).

Step 6 : N-(3-Bromo-4-fluorophenyl)-N’-hydroxy-4- [(2-methoxyethyl)amino] – 1 ,2,5- oxadiazole-3-carboximidamide [00189] N-Hydroxy-4-[(2-methoxyethyl)amino]- 1 ,2,5-oxadiazole-3-carboximidoyl chloride (46.0 g, 0.208 mol) was mixed with water (300 mL). The mixture was heated to 60 °C. 3-Bromo-4-fluoroaniline [Oakwood products, product # 013091] (43.6 g, 0.229 mol) was added and stirred for 10 min. A warm sodium bicarbonate (26.3 g, 0.313 mol) solution (300 mL water) was added over 15 min. The reaction was stirred at 60 °C for 20 min. LCMS indicated reaction completion. The reaction solution was cooled to room temperature and extracted with ethyl acetate (2 x 300 mL). The combined ethyl acetate solution was dried over sodium sulfate and concentrated to give the desired product (76.7 g, 98%) as a crude brown solid. LCMS for Ci₂Hi₄BrF₅0₃ (M+H)⁺: m/z = 374.0, 376.0. 1H NMR (400 MHz, DMSO- t_f): δ 11.55 (s, 1 H), 8.85 (s, 1 H), 7.16 (t, J= 8.8 Hz, 1 H), 7.08 (dd, J= 6.1, 2.7 Hz, 1 H), 6.75 (m, 1 H), 6.14 (t, J= 5.8 Hz, 1 H), 3.48 (t, J = 5.2 Hz, 2 H), 3.35 (dd, J= 10.8, 5.6 Hz, 2 H), 3.22 (s, 3 H).

Step 7: 4-(3-Bromo-4-fluorophenyl)-3-{4- [(2-methoxyethyl)amino]-l,2,5-oxadiazol-3- yl}-l,2,4-oxadiazol-5(4H)-one

[00190] A mixture of N-(3-bromo-4-fluorophenyl)-N’-hydroxy-4-[(2- methoxyethyl)amino]-l,2,5-oxadiazole-3-carboximidamide (76.5 g, 0.204 mol), 1,1 ‘- carbonyldiimidazole (49.7 g, 0.307 mol), and ethyl acetate (720 mL) was heated to 60 °C and stirred for 20 min. LCMS indicated reaction completed. The reaction was cooled to room temperature, washed with 1 N HC1 (2 x 750 mL), dried over sodium sulfate, and concentrated to give the desired product (80.4 g, 98%) as a crude brown solid. LCMS for

(M+H)⁺: m/z = 400.0, 402.0. 1H NMR (400 MHz, DMSO-c½): δ 7.94 (t, J = 8.2 Hz, 1 H), 7.72 (dd, J = 9.1, 2.3 Hz, 1 H), 7.42 (m, 1 H), 6.42 (t, J= 5.7 Hz, 1 H), 3.46 (t, J = 5.4 Hz, 2 H), 3.36 (t, J= 5.8 Hz, 2 H), 3.26 (s, 3 H).

Step 8: 4-(3-Bromo-4-fluorophenyl)-3-{4-[(2-hydroxyethyl)amino]-l,2,5-oxadiazol-3- yl}-l,2,4-oxadiazol-5(4H)-one

[00191] 4-(3-Bromo-4-fluoroplienyl)-3-{4-[(2-metlioxyethyl)amino]-l,2,5-oxadiazol- 3-yl}-l,2,4-oxadiazol-5(4H)-one (78.4 g, 0.196 mol) was dissolved in dichloromethane (600 mL). At -67 °C boron tribromide (37 mL, 0.392 mol) was added over 15 min. The reaction was warmed up to -10 °C in 30 min. LCMS indicated reaction completed. The reaction was stirred at room temperature for 1 hour. At 0 – 5 °C the reaction was slowly quenched with saturated sodium bicarbonate solution (1.5 L) over 30 min. The reaction temperature rose to 25 °C. The reaction was extracted with ethyl acetate (2 x 500 mL, first extraction organic layer is on the bottom and second extraction organic lager is on the top). The combined organic layers were dried over sodium sulfate and concentrated to give the desired product (75 g, 99%) as a crude brown solid. LCMS for Ci₂HioBrFN₅0₄ (M+H)⁺: m/z = 386.0, 388.0.

1H NMR (400 MHz, DMSO-^): δ 8.08 (dd, J = 6.2, 2.5 Hz, 1 H), 7.70 (m, 1 H), 7.68 (t, J = 8.7 Hz, 1 H), 6.33 (t, J = 5.6 Hz, 1 H), 4.85 (t, J= 5.0 Hz, 1 H), 3.56 (dd, J= 10.6, 5.6 Hz, 2 H), 3.29 (dd, J= 11.5, 5.9 Hz, 2 H).

Step 9 : 2-({4- [4-(3-Bromo-4-fluorophenyl)-5-oxo-4,5-dihydro- 1 ,2,4-oxadiazol-3-yl] – l,2,5-oxadiazol-3-yl}amino)ethyl methanesulfonate

[00192] To a solution of 4-(3-bromo-4-fluorophenyl)-3-{4-[(2-hydroxyethyl)amino]- l,2,5-oxadiazol-3-yl}-l,2,4-oxadiazol-5(4H)-one (1.5 kg, 3.9 mol, containing also some of the corresponding bromo-compound) in ethyl acetate (12 L) was added methanesulfonyl chloride (185 mL, 2.4 mol) dropwise over 1 h at room temperature. Triethylamine (325 mL, 2.3 mol) was added dropwise over 45 min, during which time the reaction temperature increased to 35 °C. After 2 h, the reaction mixture was washed with water (5 L), brine (1 L), dried over sodium sulfate, combined with 3 more reactions of the same size, and the solvents removed in vacuo to afford the desired product (7600 g, quantitative yield) as a tan solid. LCMS for C HnBrFNsOeS a (M+Na)⁺: m/z = 485.9, 487.9. ^!H NMR (400 MHz, DMSO- d₆): δ 8.08 (dd, J = 6.2, 2.5 Hz, 1 H), 7.72 (m, 1 H), 7.58 (t, J = 8.7 Hz, 1 H), 6.75 (t, J = 5.9 Hz, 1 H), 4.36 (t, J = 5.3 Hz, 2 H), 3.58 (dd, J = 11.2, 5.6 Hz, 2 H), 3.18 (s, 3 H).

Step 10: 3-{4-[(2-Azidoethyl)amino]-l,2,5-oxadiazol-3-yl}-4-(3-bromo-4-fluorophenyl)- l,2,4-oxadiazol-5(4H)-one

To a solution of 2-({4-[4-(3-bromo-4-f uorophenyl)-5-oxo-4,5-dihydro-l ,2,4- oxadiazol-3-yl]-l ,2,5-oxadiazol-3-yl}amino)ethyl methanesulfonate (2.13 kg, 4.6 mol, containing also some of the corresponding bromo-compound) in dimethylformamide (4 L) stirring in a 22 L flask was added sodium azide (380 g, 5.84 mol). The reaction was heated at 50 °C for 6 h, poured into ice/water (8 L), and extracted with 1 : 1 ethyl acetate:heptane (20 L). The organic layer was washed with water (5 L) and brine (5 L), and the solvents removed in vacuo to afford the desired product (1464 g, 77%) as a tan solid. LCMS for CnHgBrFNsOs a

(M+Na)⁺: m/z = 433.0, 435.0. ^!H NMR (400 MHz, DMSO-J₆): δ 8.08 (dd, J = 6.2, 2.5 Hz, 1 H), 7.72 (m, 1 H), 7.58 (t, J= 8.7 Hz, 1 H), 6.75 (t, J = 5.7 Hz, 1 H), 3.54 (t, J = 5.3 Hz, 2 H), 3.45 (dd, J= 1 1.1 , 5.2 Hz, 2 H).

Step 11: 3-{4-[(2-Aminoethyl)amino]-l,2,5-oxadiazol-3-yl}-4-(3-bromo-4-fluorophenyl)-

1.2.4- oxadiazol-5(4H)-one hydrochloride

[00194] Sodium iodide (1080 g, 7.2 mol) was added to 3-{4-[(2-azidoethyl)amino]-

1.2.5- oxadiazol-3-yl}-4-(3-bromo-4-fluorophenyl)-l ,2,4-oxadiazol-5(4H)-one (500 g, 1.22 mol) in methanol (6 L). The mixture was allowed to stir for 30 min during which time a mild exotherm was observed. Chlorotrimethylsilane (930 mL, 7.33 mol) was added as a solution in methanol (1 L) dropwise at a rate so that the temperature did not exceed 35 °C, and the reaction was allowed to stir for 3.5 h at ambient temperature. The reaction was neutralized with 33 wt% solution of sodium thiosulfate pentahydrate in water (-1.5 L), diluted with water (4 L), and the pH adjusted to 9 carefully with solid potassium carbonate (250 g – added in small portions: watch foaming). Di-ieri-butyl dicarbonate (318 g, 1.45 mol) was added and the reaction was allowed to stir at room temperature. Additional potassium carbonate (200 g) was added in 50 g portions over 4 h to ensure that the pH was still at or above 9. After stirring at room temperature overnight, the solid was filtered, triturated with water (2 L), and then MTBE (1.5 L). A total of 11 runs were performed (5.5 kg, 13.38 mol). The combined solids were triturated with 1 : 1 THF:dichloromethane (24 L, 4 runs in a 20 L rotary evaporator flask, 50 °C, 1 h), filtered, and washed with dichloromethane (3 L each run) to afford an off- white solid. The crude material was dissolved at 55 °C tetrahydrofuran (5 mL/g), treated with decolorizing carbon (2 wt%) and silica gel (2 wt%), and filtered hot through celite to afford the product as an off-white solid (5122 g). The combined MTBE, THF, and dichloromethane filtrates were concentrated in vacuo and chromatographed (2 kg silica gel, heptane with a 0-100% ethyl acetate gradient, 30 L) to afford more product (262 g). The combined solids were dried to a constant weight in a convection oven (5385 g, 83%).

In a 22 L flask was charged hydrogen chloride (4 N solution in 1 ,4-dioxane, 4 L, 16 mol). tert-Butyl [2-({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-l ,2,4- oxadiazol-3-yl]-l ,2,5-oxadiazol-3-yl}amino)ethyl]carbamate (2315 g, 4.77 mol) was added as a solid in portions over 10 min. The slurry was stirred at room temperature and gradually became a thick paste that could not be stirred. After sitting overnight at room temperature, the paste was slurried in ethyl acetate (10 L), filtered, re-slurried in ethyl acetate (5 L), filtered, and dried to a constant weight to afford the desired product as a white solid (combined with other runs, 5 kg starting material charged, 41 13 g, 95%). LCMS for

Ci₂H_nBrFN₆0₃ (M+H)⁺: m/z = 384.9, 386.9. 1H NMR (400 MHz, DMSO-^): δ 8.12 (m, 4 H), 7.76 (m, 1 H), 7.58 (t, J = 8.7 Hz, 1 H), 6.78 (t, J = 6.1 Hz, 1 H), 3.51 (dd, J = 1 1.8, 6.1 Hz, 2 H), 3.02 (m, 2 H).

Step 12: tert-Butyl ({[2-({4-[4-(3-bromo-4-nuorophenyl)-5-oxo-4,5-dihydro-l,2,4- oxadiazol-3-yl]-l,2,5-oxadiazol-3-yl}amino)ethyl]amino}sulfonyl)carbamate

A 5 L round bottom flask was charged with chlorosulfonyl isocyanate [Aldrich, product # 142662] (149 mL, 1.72 mol) and dichloromethane (1.5 L) and cooled using an ice bath to 2 °C. teri-Butanol (162 mL, 1.73 mol) in dichloromethane (200 mL) was added dropwise at a rate so that the temperature did not exceed 10 °C. The resulting solution was stirred at room temperature for 30-60 min to provide tert-bvAy\ [chlorosulfonyl]carbamate.

A 22 L flask was charged with 3- {4-[(2-aminoethyl)amino]- 1 ,2,5-oxadiazol-3- yl}-4-(3-bromo-4-fluorophenyl)-l,2,4-oxadiazol-5(4H)-one hydrochloride (661 g, 1.57 mol) and 8.5 L dichloromethane. After cooling to -15 °C with an ice/salt bath, the solution oi tert- Vmtvl i Vi 1 r>rosulfonyl]carbamate (prepared as above) was added at a rate so that the temperature did not exceed -10 °C (addition time 7 min). After stirring for 10 min, triethylamine (1085 mL, 7.78 mol) was added at a rate so that the temperature did not exceed -5 °C (addition time 10 min). The cold bath was removed, the reaction was allowed to warm to 10 °C, split into two portions, and neutralized with 10% cone HC1 (4.5 L each portion). Each portion was transferred to a 50 L separatory funnel and diluted with ethyl acetate to completely dissolve the white solid (-25 L). The layers were separated, and the organic layer was washed with water (5 L), brine (5 L), and the solvents removed in vacuo to afford an off- white solid. The solid was triturated with MTBE (2 x 1.5 L) and dried to a constant weight to afford a white solid. A total of 4113 g starting material was processed in this manner (5409 g, 98%). 1H NMR (400 MHz, DMSO-^): δ 10.90 (s, 1 H), 8.08 (dd, J = 6.2, 2.5 Hz, 1 H), 7.72 (m, 1 H), 7.59 (t, J = 8.6 Hz, 1 H), 6.58 (t, J = 5.7 Hz, 1 H), 3.38 (dd, J= 12.7, 6.2 Hz, 2 H), 3.10 (dd, J= 12.1 , 5.9 Hz, 2 H), 1.41 (s, 9 H).

Step 13: N-[2-({4-[4-(3-Bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-l,2,4-oxadiazol-3-yl]- l,2,5-oxadiazol-3-yl}amino)ethyl]sulfamide

[00198] To a 22 L flask containing 98:2 trifluoroacetic acid:water (8.9 L) was added tert-bvXyl ({[2-({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-l,2,4-oxadiazol-3-yl]- l,2,5-oxadiazol-3-yl}amino)ethyl]amino}sulfonyl)carbamate (1931 g, 3.42 mol) in portions over 10 minutes. The resulting mixture was stirred at room temperature for 1.5 h, the solvents removed in vacuo, and chased with dichloromethane (2 L). The resulting solid was treated a second time with fresh 98:2 trifluoroacetic acid:water (8.9 L), heated for 1 h at 40- 50 °C, the solvents removed in vacuo, and chased with dichloromethane (3 x 2 L). The resulting white solid was dried in a vacuum drying oven at 50 °C overnight. A total of 5409 g was processed in this manner (4990 g, quant, yield). LCMS for C₁₂H₁₂BrFN₇0₅S (M+H)⁺: m/z = 463.9, 465.9. 1H NMR (400 MHz, DMSO- ): δ 8.08 (dd, J = 6.2, 2.5 Hz, 1 H), 7.72 (m, 1 H), 7.59 (t, J= 8.7 Hz, 1 H), 6.67 (t, J = 5.9 Hz, 1H), 6.52 (t, J= 6.0 Hz, 1 H), 3.38 (dd, J = 12.7, 6.3 Hz, 2 H), 3.11 (dd, J = 12.3, 6.3 Hz). Step 14: 4-({2-[(Aminosulfonyl)amino]ethyl}amino)-N-(3-bromo-4-fluorophenyl)-N’- hydroxy-l,2,5-oxadiazole-3-carboximidamide

[00199] To a crude mixture of N-[2-({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5- dihydro-l,2,4-oxadiazol-3-yl]-l,2,5-oxadiazol-3-yl}amino)ethyl]sulfamide (2.4 mol) containing residual amounts of trifluoroacetic acid stirring in a 22 L flask was added THF (5 L). The resulting solution was cooled to 0 °C using an ice bath and 2 N NaOH (4 L) was added at a rate so that the temperature did not exceed 10 °C. After stirring at ambient temperature for 3 h (LCMS indicated no starting material remained), the pH was adjusted to 3-4 with concentrated HC1 (-500 mL). The THF was removed in vacuo, and the resulting mixture was extracted with ethyl acetate (15 L). The organic layer was washed with water (5 L), brine (5 L), and the solvents removed in vacuo to afford a solid. The solid was triturated with MTBE (2 x 2 L), combined with three other reactions of the same size, and dried overnight in a convection oven to afford a white solid (3535 g). The solid was recrystallized (3 x 22 L flasks, 2:1 watenethanol, 14.1 L each flask) and dried in a 50 °C convection oven to a constant weight to furnish the title compound as an off-white solid (3290 g, 78%). LCMS for CnHnBrF yC S (M+H)⁺: m/z = 437.9, 439.9. i NMR (400 MHz, DMSO-J^): δ 11.51 (s, 1 H), 8.90 (s, 1 H), 7.17 (t, J= 8.8 Hz, 1 H), 7.11 (dd, J= 6.1, 2.7 Hz, 1 H), 6.76 (m, 1 H), 6.71 (t, J = 6.0 Hz, 1 H), 6.59 (s, 2 H), 6.23 (t, J= 6.1 Hz, 1 H), 3.35 (dd, J= 10.9, 7.0 Hz, 2 H), 3.10 (dd, J= 12.1, 6.2 Hz, 2 H).

PATENT

WO 2010005958

https://www.google.com/patents/WO2010005958A2?cl=en

EXAMPLES Example 1

4-({2-[(Aminosulfonyl)amino]ethyl}amino)-7V-(3-bromo-4-fluorophenyl)-iV’-hydroxy- l,2,5-oxadiazole-3-carboximidamide

Step A: 4-Amino-N’-hydroxy-l,2,5-oxadiazole-3-carboximidamide

Malononitrile [Aldrich, product # M1407] (320.5 g, 5 mol) was added to water (7 L) preheated to 45 ⁰C and stirred for 5 min. The resulting solution was cooled in an ice bath and sodium nitrite (380 g, 5.5 mol) was added. When the temperature reached 10 ⁰C, 6 N hydrochloric acid (55 mL) was added. A mild exothermic reaction ensued with the temperature reaching 16 ⁰C. After 15 min the cold bath was removed and the reaction mixture was stirred for 1.5 hrs at 16-18 ⁰C. The reaction mixture was cooled to 13 ⁰C and 50% aqueous hydroxylamine (990 g, 15 mol) was added all at once. The temperature rose to 26 ⁰C. When the exothermic reaction subsided the cold bath was removed and stirring was continued for 1 hr at 26-27⁰C, then it was slowly brought to reflux. Reflux was maintained for 2 hrs and then the reaction mixture was allowed to cool overnight. The reaction mixture was stirred in an ice bath and 6 N hydrochloric acid (800 mL) was added in portions over 40 min to pH 7.0. Stirring was continued in the ice bath at 5 ⁰C. The precipitate was collected by filtration, washed well with water and dried in a vacuum oven (50 ⁰C) to give the desired product (644 g, 90%). LCMS for C₃H₆N₅O₂ (M+H)+: m/z = 144.0. ¹³C NMR (75 MHz, CD₃OD): δ 156.0, 145.9, 141.3. Step B: 4-Amino-N-hydroxy-l,2,5-oxadiazole-3-carboximidoyl chloride

4-Amino-N’-hydroxy-l,2,5-oxadiazole-3-carboximidamide (422 g, 2.95 mol) was added to a mixture of water (5.9 L), acetic acid (3 L) and 6 Ν hydrochloric acid (1.475 L, 3 eq.) and this suspension was stirred at 42 – 45 ⁰C until complete solution was achieved. Sodium chloride (518 g, 3 eq.) was added and this solution was stirred in an ice/water/methanol bath. A solution of sodium nitrite (199.5 g, 0.98 eq.) in water (700 mL) was added over 3.5 hrs while maintaining the temperature below 0 ⁰C. After complete addition stirring was continued in the ice bath for 1.5 hrs and then the reaction mixture was allowed to warm to 15 ⁰C. The precipitate was collected by filtration, washed well with water, taken in ethyl acetate (3.4 L), treated with anhydrous sodium sulfate (500 g) and stirred for 1 hr. This suspension was filtered through sodium sulfate (200 g) and the filtrate was concentrated on a rotary evaporator. The residue was dissolved in methyl f-butyl ether (5.5 L), treated with charcoal (40 g), stirred for 40 min and filtered through Celite. The solvent was removed in a rotary evaporator and the resulting product was dried in a vacuum oven (45 ⁰C) to give the desired product (256 g, 53.4%). LCMS for C₃H₄ClN₄O₂(M+H)+: m/z = 162.9. 13c NMR (100 MHz, CD₃OD): δ 155.8, 143.4, 129.7.

Step C: 4-Amino-N’-hydroxy-N-(2-methoxyethyl)- 1 ,2,5-oxadiazole-3-carboximidamide

4-Amino-N-hydroxy-l,2,5-oxadiazole-3-carboximidoyl chloride (200.0 g, 1.23 mol) was mixed with ethyl acetate (1.2 L). At 0-5⁰C 2-methoxyethylamine [Aldrich, product # 143693] (119.0 mL, 1.35 mol) was added in one portion while stirring. The reaction temperature rose to 41 ⁰C. The reaction was cooled to 0 – 5 °C. Triethylamine (258 mL, 1.84 mol) was added. After stirring 5 min, LCMS indicated reaction completion. The reaction solution was washed with water (500 mL) and brine (500 mL), dried over sodium sulfate, and concentrated to give the desired product (294 g, 119%) as a crude dark oil. LCMS for C₆Hi₂N₅O₃ (M+H)⁺: m/z = 202.3. ¹H NMR (400 MHz, DMSO-J₆): δ 10.65 (s, 1 H), 6.27 (s, 2 H), 6.10 (t, J= 6.5 Hz, 1 H), 3.50 (m, 2 H), 3.35 (d, J= 5.8 Hz, 2 H), 3.08 (s, 3 H).

Step D: N’-Hydroxy-4-[(2-methoxyethyl)amino]-l ,2,5-oxadiazole-3-carboximidamide

4-Amino-N’-hydroxy-N-(2-methoxyethyl)-l,2,5-oxadiazole-3-carboximidaniide (248.0 g, 1.23 mol) was mixed with water (1 L). Potassium hydroxide (210 g, 3.7 mol) was added. The reaction was refluxed at 100 ⁰C overnight (15 hours). TLC with 50% ethyl acetate (containing 1% ammonium hydroxide) in hexane indicated reaction completed (product Rf= 0.6, starting material Rf = 0.5). LCMS also indicated reaction completion. The reaction was cooled to room temperature and extracted with ethyl acetate (3 x 1 L). The combined ethyl acetate solution was dried over sodium sulfate and concentrated to give the desired product (201 g, 81%) as a crude off-white solid. LCMS for C₆H₁₂N₅O₃ (M+H)⁺: m/z = 202.3 ¹H NMR (400 MHz, DMSO-Gk): δ 10.54 (s, 1 H), 6.22 (s, 2 H), 6.15 (t, J= 5.8 Hz, 1 H), 3.45 (t, J= 5.3 Hz, 2 H), 3.35 (m, 2 H), 3.22 (s, 3 H).

Step E: N-Hydroxy-4-[(2-methoxyethyl)amino]-l,2,5-oxadiazole-3-carboximidoyl chloride

Ν. ,Ν O

At room temperature N’-hydroxy-4-[(2-methoxyethyl)amino]-l,2,5-oxadiazole-3- carboximidamide (50.0 g, 0.226 mol) was dissolved in 6.0 M hydrochloric acid aqueous solution (250 mL, 1.5 mol). Sodium chloride (39.5 g, 0.676 mol) was added followed by water (250 mL) and ethyl acetate (250 mL). At 3-5 ⁰C a previously prepared aqueous solution (100 mL) of sodium nitrite (15.0 g, 0.217 mol) was added slowly over 1 hr. The reaction was stirred at 3 – 8 ⁰C for 2 hours and then room temperature over the weekend. LCMS indicated reaction completed. The reaction solution was extracted with ethyl acetate (2 x 200 mL). The combined ethyl acetate solution was dried over sodium sulfate and concentrated to give the desired product (49.9 g, 126%) as a crude white solid. LCMS for C₆Hi₀ClN₄O₃ (M+H)⁺: m/z = 221.0. ¹H NMR (400 MHz, DMSO-J₆): δ 13.43 (s, 1 H), 5.85 (t, J= 5.6 Hz, 1 H), 3.50 (t, J= 5.6 Hz, 2 H), 3.37(dd, J= 10.8, 5.6 Hz, 2 H), 3.25 (s, 3 H).

Step F: N-(3-Bromo-4-fluorophenyl)-N’-hydroxy-4-[(2-methoxyethyl)amino]- 1 ,2,5- oxadiazole-3 -carboximidamide

N-Hydroxy-4-[(2-methoxyethyl)amino]-l,2,5-oxadiazole-3-carboximidoyl chloride (46.0 g, 0.208 mol) was mixed with water (300 mL). The mixture was heated to 60 °C. 3-Bromo-4- fluoroaniline [Oakwood products, product # 013091] (43.6 g, 0.229 mol) was added and stirred for 10 nrn^‘n. A warm sodium bicarbonate (26.3 g, 0.313 mol) solution (300 mL water) was added over 15 min. The reaction was stirred at 60 ⁰C for 20 min. LCMS indicated reaction completion. The reaction solution was cooled to room temperature and extracted with ethyl acetate (2 x 300 mL). The combined ethyl acetate solution was dried over sodium sulfate and concentrated to give the desired product (76.7 g, 98%) as a crude brown solid. LCMS for Ci₂Hi₄BrFN₅O₃ (M+H)⁺: m/z = 374.0, 376.0. ¹H NMR (400 MHz, DMSO-J₆): δ 11.55 (s, 1 H), 8.85 (s, 1 H), 7.16 (t, J= 8.8 Hz, 1 H), 7.08 (dd, J= 6.1, 2.7 Hz, 1 H), 6.75 (m, 1 H), 6.14 (t, J= 5.8 Hz, 1 H), 3.48 (t, J= 5.2 Hz, 2 H), 3.35 (dd, J= 10.8, 5.6 Hz, 2 H), 3.22 (s, 3 H).

Step G: 4-(3-Bromo-4-fluorophenyl)-3-{4-[(2-methoxyethyl)amino]-l,2,5-oxadiazol-3-yl}- 1 ,2,4-oxadiazol-5(4H)-one

A mixture of N-(3-bromo-4-fluorophenyl)-N’-hydroxy-4-[(2-methoxyethyl)amino]-l,2,5- oxadiazole-3-carboximidamide (76.5 g, 0.204 mol), l,r-carbonyldiimidazole (49.7 g, 0.307 mol), and ethyl acetate (720 mL) was heated to 60 ⁰C and stirred for 20 min. LCMS indicated reaction completed. The reaction was cooled to room temperature, washed with 1 Ν HCl (2 x 750 mL), dried over sodium sulfate, and concentrated to give the desired product (80.4 g, 98%) as a crude brown solid. LCMS for C₁₃H₁₂BrFN₅O₄ (M+H)⁺: m/z = 400.0, 402.0. ¹H NMR (400 MHz, OMSO-d₆): δ 7.94 (t, J= 8.2 Hz, 1 H), 7.72 (dd, J= 9.1, 2.3 Hz, 1 H), 7.42 (m, 1 H), 6.42 (t, J= 5.7 Hz, 1 H), 3.46 (t, J= 5.4 Hz, 2 H), 3.36 (t, J= 5.8 Hz, 2 H), 3.26 (s, 3 H).

Step H: 4-(3-Bromo-4-fluorophenyl)-3-{4-[(2-liydroxyethyl)amino]-l,2,5-oxadiazol-3-yl}- 1 ,2,4-oxadiazol-5(4H)-one

4-(3-Bromo-4-fluorophenyl)-3-{4-[(2-methoxyetliyl)amino]-l,2,5-oxadiazol-3-yl}-l,2,4- oxadiazol-5(4H)-one (78.4 g, 0.196 mol) was dissolved in dichloromethane (600 mL). At -67 ⁰C boron tribromide (37 mL, 0.392 mol) was added over 15 min. The reaction was warmed up to -10 ⁰C in 30 min. LCMS indicated reaction completed. The reaction was stirred at room temperature for 1 hour. At 0 – 5 ⁰C the reaction was slowly quenched with saturated sodium bicarbonate solution (1.5 L) over 30 min. The reaction temperature rose to 25 ⁰C. The reaction was extracted with ethyl acetate (2 x 500 mL, first extraction organic layer is on the bottom and second extraction organic lager is on the top). The combined organic layers were dried over sodium sulfate and concentrated to give the desired product (75 g, 99%) as a crude brown solid. LCMS for C₁₂H₁₀BrFN₅O₄ (M+H)⁺: m/z = 386.0, 388.0. ¹H NMR (400 MHz, DMSO-^₆): δ 8.08 (dd, J= 6.2, 2.5 Hz, 1 H), 7.70 (m, 1 H), 7.68 (t, J= 8.7 Hz, 1 H), 6.33 (t, J= 5.6 Hz, 1 H), 4.85 (t, J= 5.0 Hz, 1 H), 3.56 (dd, J= 10.6, 5.6 Hz, 2 H), 3.29 (dd, J= 11.5, 5.9 Hz, 2 H).

Step I: 2-({4-[4-(3-Bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-l,2,4-oxadiazol-3-yl]-l,2,5- oxadiazol-3-yl}amino)ethyl methanesulfonate

To a solution of 4-(3-bromo-4-fluorophenyl)-3-{4-[(2-hydroxyethyl)amino]-l,2,5-oxadiazol- 3-yl}-l,2,4-oxadiazol-5(4H)-one (1.5 kg, 3.9 mol, containing also some of the corresponding bromo-compound) in ethyl acetate (12 L) was added methanesulfonyl chloride (185 mL, 2.4 mol) dropwise over 1 h at room temperature. Triethylamine (325 mL, 2.3 mol) was added dropwise over 45 min, during which time the reaction temperature increased to 35 ⁰C. After 2 h, the reaction mixture was washed with water (5 L), brine (I L), dried over sodium sulfate, combined with 3 more reactions of the same size, and the solvents removed in vacuo to afford the desired product (7600 g, quantitative yield) as a tan solid. LCMS for

Ci₃HnBrFN₅O₆SNa (M+Na)⁺: m/z = 485.9, 487.9. ¹H NMR (400 MHz, DMSCW₆): δ 8.08 (dd, J= 6.2, 2.5 Hz, 1 H), 7.72 (m, 1 H), 7.58 (t, J= 8.7 Hz, 1 H), 6.75 (t, J- 5.9 Hz, 1 H), 4.36 (t, J= 5.3 Hz, 2 H), 3.58 (dd, J= 11.2, 5.6 Hz, 2 H), 3.18 (s, 3 H).

Step J: 3-{4-[(2-Azidoethyl)amino]-l,2,5-oxadiazol-3-yl}-4-(3-bromo-4-fluorophenyl)- 1 ,2,4-oxadiazol-5(4H)-one

To a solution of 2-({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-l,2,4-oxadiazol-3-yl]- l,2,5-oxadiazol-3-yl}amino)ethyl methanesulfonate (2.13 kg, 4.6 mol, containing also some of the corresponding bromo-compound) in dimethylformamide (4 L) stirring in a 22 L flask was added sodium azide (380 g, 5.84 mol). The reaction was heated at 50⁰C for 6 h, poured into ice/water (8 L), and extracted with 1 : 1 ethyl acetate:heptane (20 L). The organic layer was washed with water (5 L) and brine (5 L), and the solvents removed in vacuo to afford the desired product (1464 g, 77%) as a tan solid. LCMS for C₁₂H₈BrFN₈O₃Na (M+Na)⁺: m/z =

433.0, 435.0. ¹H NMR (400 MHz, DMSO-*/*): δ 8.08 (dd, J= 6.2, 2.5 Hz, 1 H), 7.72 (m, 1 H), 7.58 (t, J= 8.7 Hz, 1 H), 6.75 (t, J= 5.7 Hz, 1 H), 3.54 (t, J= 5.3 Hz, 2 H), 3.45 (dd, J= 11.1, 5.2 Hz, 2 H).

Step K: 3-{4-[(2-Aminoethyl)amino]-l,2,5-oxadiazol-3-yl}-4-(3-bromo-4-fluorophenyl)- 1 ,2,4-oxadiazol-5(4H)-one hydrochloride

Sodium iodide (1080 g, 7.2 mol) was added to 3-{4-[(2-azidoethyl)amino]-l,2,5-oxadiazol-3- yl}-4-(3-bromo-4-fluorophenyl)-l,2,4-oxadiazol-5(4H)-one (500 g, 1.22 mol) in methanol (6 L). The mixture was allowed to stir for 30 min during which time a mild exotherm was observed. Chlorotrimethylsilane (930 mL, 7.33 mol) was added as a solution in methanol (1 L) dropwise at a rate so that the temperature did not exceed 35 ⁰C, and the reaction was allowed to stir for 3.5 h at ambient temperature. The reaction was neutralized with 33 wt% solution of sodium thiosulfate pentahydrate in water (~1.5 L), diluted with water (4 L), and the pΗ adjusted to 9 carefully with solid potassium carbonate (250 g – added in small portions: watch foaming). Di-fe/t-butyl dicarbonate (318 g, 1.45 mol) was added and the reaction was allowed to stir at room temperature. Additional potassium carbonate (200 g) was added in 50 g portions over 4 h to ensure that the pΗ was still at or above 9. After stirring at room temperature overnight, the solid was filtered, triturated with water (2 L), and then MTBE (1.5 L). A total of 11 runs were performed (5.5 kg, 13.38 mol). The combined solids were triturated with 1 : 1 TΗF:dichloromethane (24 L, 4 runs in a 20 L rotary evaporator flask, 50 ⁰C, 1 h), filtered, and washed with dichloromethane (3 L each run) to afford an off- white solid. The crude material was dissolved at 55 ⁰C tetrahydrofuran (5 mL/g), treated with decolorizing carbon (2 wt%) and silica gel (2 wt%), and filtered hot through celite to afford the product as an off-white solid (5122 g). The combined MTBE, THF, and dichloromethane filtrates were concentrated in vacuo and chromatographed (2 kg silica gel, heptane with a 0-100% ethyl acetate gradient, 30 L) to afford more product (262 g). The combined solids were dried to a constant weight in a convection oven (5385 g, 83%).

In a 22 L flask was charged hydrogen chloride (4 N solution in 1,4-dioxane, 4 L, 16 mol). fert-Butyl [2-({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-l,2,4-oxadiazol-3-yl]- l,2,5-oxadiazol-3-yl}amino)ethyl]carbamate (2315 g, 4.77 mol) was added as a solid in portions over 10 min. The slurry was stirred at room temperature and gradually became a thick paste that could not be stirred. After sitting overnight at room temperature, the paste was slurried in ethyl acetate (10 L), filtered, re-slurried in ethyl acetate (5 L), filtered, and dried to a constant weight to afford the desired product as a white solid (combined with other runs, 5 kg starting material charged, 4113 g, 95%). LCMS for C₁₂H_nBrFN₆O₃ (M+H)⁺: m/z

= 384.9, 386.9. ¹H NMR (400 MHz, DMSO-J₆): δ 8.12 (m, 4 H), 7.76 (m, 1 H), 7.58 (t, J= 8.7 Hz, 1 H), 6.78 (t, J= 6.1 Hz, 1 H), 3.51 (dd, J= 11.8, 6.1 Hz, 2 H), 3.02 (m, 2 H).

Step L: tert-Butyl ({[2-({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-diliydro-l,2,4-oxadiazol- 3-yl]-l,2,5-oxadiazol-3-yl}amino)ethyl]amino}sulfonyl)carbamate

A 5 L round bottom flask was charged with chlorosulfonyl isocyanate [Aldrich, product #

142662] (149 mL, 1.72 mol) and dichloromethane (1.5 L) and cooled using an ice bath to 2 ⁰C. tert-Butanol (162 mL, 1.73 mol) in dichloromethane (200 mL) was added dropwise at a rate so that the temperature did not exceed 10 ⁰C. The resulting solution was stirred at room temperature for 30-60 min to provide tert-butyl [chlorosulfonyljcarbamate.

A 22 L flask was charged with 3-{4-[(2-aminoethyl)amino]-l,2,5-oxadiazol-3-yl}-4-(3- bromo-4-fluorophenyl)-l,2,4-oxadiazol-5(4H)-one hydrochloride (661 g, 1.57 mol) and 8.5 L dichloromethane. After cooling to -15 ⁰C with an ice/salt bath, the solution of tert-butyl [chlorosulfonyl]carbamate (prepared as above) was added at a rate so that the temperature did not exceed -10 ⁰C (addition time 7 min). After stirring for 10 min, triethylamine (1085 mL, 7.78 mol) was added at a rate so that the temperature did not exceed -5 ⁰C (addition time 10 min). The cold bath was removed, the reaction was allowed to warm to 10 ⁰C, split into two portions, and neutralized with 10% cone HCl (4.5 L each portion). Each portion was transferred to a 50 L separatory funnel and diluted with ethyl acetate to completely dissolve the white solid (~25 L). The layers were separated, and the organic layer was washed with water (5 L), brine (5 L), and the solvents removed in vacuo to afford an off-white solid. The solid was triturated with MTBE (2 x 1.5 L) and dried to a constant weight to afford a white solid. A total of 4113 g starting material was processed in this manner (5409 g, 98%). *Η NMR (400 MHz, OMSO-d₆): δ 10.90 (s, 1 H), 8.08 (dd, J= 6.2, 2.5 Hz, 1 H), 7.72 (m, 1 H), 7.59 (t, J= 8.6 Hz, 1 H), 6.58 (t, J= 5.7 Hz, 1 H), 3.38 (dd, J= 12.7, 6.2 Hz, 2 H), 3.10 (dd, J = 12.1, 5.9 Hz, 2 H), 1.41 (s, 9 H). Step M: N-[2-({4-[4-(3-Bromo-4-fluorophenyl)-5-oxo-4,5-dmydro-l ,2,4-oxadiazol-3-yl]- l,2,5-oxadiazol-3-yl}amino)ethyl]sulfamide

To a 22 L flask containing 98:2 trifluoroacetic acid:water (8.9 L) was added tert-butyl ({[2- ({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-diliydro-l,2,4-oxadiazol-3-yl]-l,2,5-oxadiazol-3- yl}amino)ethyl]amino}sulfonyl)carbamate (1931 g, 3.42 mol) in portions over 10 minutes. The resulting mixture was stirred at room temperature for 1.5 h, the solvents removed in vacuo, and chased with dichloromethane (2 L). The resulting solid was treated a second time with fresh 98:2 trifluoroacetic acid:water (8.9 L), heated for 1 h at 40-50 ⁰C, the solvents removed in vacuo, and chased with dichloromethane (3 x 2 L). The resulting white solid was dried in a vacuum drying oven at 50 ⁰C overnight. A total of 5409 g was processed in this manner (4990 g, quant, yield). LCMS for C]₂H₁₂BrFN₇O₅S (M+H)⁺: m/z = 463.9, 465.9.

¹H NMR (400 MHz, OM$>O-d₆): δ 8.08 (dd, J= 6.2, 2.5 Hz, 1 H), 7.72 (m, 1 H), 7.59 (t, J= 8.7 Hz, 1 H), 6.67 (t, J= 5.9 Hz, IH), 6.52 (t, J= 6.0 Hz, 1 H), 3.38 (dd, J= 12.7, 6.3 Hz, 2 H), 3.11 (dd, J= 12.3, 6.3 Hz).

Step N: 4-( {2-[(Aminosulfonyl)amino]ethyl} amino)-N-(3-bromo-4-fluorophenyl)-N- hydroxy-l,2,5-oxadiazole-3-carboximidamide

To a crude mixture of N-[2-({4-[4-(3-bromo-4-fluorophenyl)-5-oxo-4,5-dihydro-l,2,4- oxadiazol-3-yl]-l,2,5-oxadiazol-3-yl}amino)ethyl]sulfamide (2.4 mol) containing residual amounts of trifluoroacetic acid stirring in a 22 L flask was added THF (5 L). The resulting solution was cooled to 0 °C using an ice bath and 2 Ν NaOH (4 L) was added at a rate so that the temperature did not exceed 10 ⁰C. After stirring at ambient temperature for 3 h (LCMS indicated no starting material remained), the pH was adjusted to 3-4 with concentrated HCl (-500 mL). The THF was removed in vacuo, and the resulting mixture was extracted with ethyl acetate (15 L). The organic layer was washed with water (5 L), brine (5 L), and the solvents removed in vacuo to afford a solid. The solid was triturated with MTBE (2 x 2 L), combined with three other reactions of the same size, and dried overnight in a convection oven to afford a white solid (3535 g). The solid was recrystallized (3 x 22 L flasks, 2: 1 water: ethanol, 14.1 L each flask) and dried in a 50 ⁰C convection oven to a constant weight to furnish the title compound as an off-white solid (3290 g, 78%). LCMS for C_nH₁₄BrFN₇O₄S (M+H)⁺: m/z = 437.9, 439.9. ¹H NMR (400 MHz, DMSO-J₆): δ 11.51 (s, 1 H), 8.90 (s, 1 H), 7.17 (t, J= 8.8 Hz, 1 H), 7.11 (dd, J= 6.1, 2.7 Hz, 1 H), 6.76 (m, 1 H), 6.71 (t, J= 6.0 Hz, 1 H), 6.59 (s, 2 H), 6.23 (t, J= 6.1 Hz, 1 H), 3.35 (dd, J= 10.9, 7.0 Hz, 2 H), 3.10 (dd, J= 12.1, 6.2 Hz, 2 H).

The final product was an anhydrous crystalline solid. The water content was determined to be less than 0.1% by Karl Fischer titration.

CLIP

INCB24360

Company:Incyte Corp.
Target: IDO1
Disease: Cancer

Incyte’s Andrew P. Combs presented the company’s clinical candidate for cancer immunotherapy. The basic tenet of this burgeoning field is that the human body’s immune system is a tremendous resource for fighting disease; scientists just need to figure out how to unleash it. One target that’s proven to be particularly attractive for this purpose in recent years is indoleamine-2,3-dioxygenase-1, or IDO1 (C&EN, April 6, page 10).

IDO1 plays a role in signaling the immune system to stand down from attacking foreign bodies it might otherwise go after, such as fetuses. Tumors also produce IDO1 to evade the immune system, so molecules that can inhibit this enzyme could bring the full force of the body’s defenses to bear on these deadly invaders.

Incyte’s search for an IDO1 inhibitor began with a high-throughput screen, which led to a proof-of-concept compound. But the compound had poor oral bioavailability. What’s more, the molecule and its analogs underwent glucuronidation during its metabolism: Enzymes tacked on a glucuronic acid group to the structure’s amidoxime, which was key to its activity.

The chemists reasoned they could block this metabolism by sterically hindering that position. Making such molecules proved to be more difficult than they expected. But then they unearthed a Latvian paper from 1993 that gave them the synthetic method they needed to make the series of compounds that would lead to their clinical candidate INCB24360 (epacadostat).

With its furazan core, as well as its amidoxime, bromide, and sulfuric diamide functional groups, INCB24360 is something of an odd duck, Combs acknowledged. “Some of you in the audience may be looking at this and saying, ‘That molecule does not look like something I would bring forward or maybe even make,’ ” he said, noting that the structure breaks many medicinal chemistry rules. “We’re a data-centric company, and we followed the data, not the rules,” Combs told C&EN.

The compound has completed Phase I clinical trials and is now being used in collaborative studies with several other pharmaceutical companies that combine INCB24360 with other cancer immunotherapy agents.

TEAMWORK

Incyte’s team (from left): Andrew Combs, Dilip Modi, Joe Glenn, Brent Douty, Padmaja Polam, Brian Wayland, Rick Sparks, Wenyu Zhu, and Eddy Yue.

Credit: Incyte

WO2007113648A2 *	Mar 26, 2007	Oct 11, 2007	Pfizer Products Inc.	Ctla4 antibody combination therapy
US20070185165 *	Dec 19, 2006	Aug 9, 2007	Combs Andrew P	N-hydroxyamidinoheterocycles as modulators of indoleamine 2,3-dioxygenase
US20100055111 *	Feb 14, 2008	Mar 4, 2010	Med. College Of Georgia Research Institute, Inc.	Indoleamine 2,3-dioxygenase, pd-1/pd-l pathways, and ctla4 pathways in the activation of regulatory t cells
US20120058079 *	Nov 11, 2011	Mar 8, 2012	Incyte Corporation, A Delaware Corporation	1,2,5-Oxadiazoles as Inhibitors of Indoleamine 2,3-Dioxygenase

REFERENCES

1: Vacchelli E, Aranda F, Eggermont A, Sautès-Fridman C, Tartour E, Kennedy EP, Platten M, Zitvogel L, Kroemer G, Galluzzi L. Trial watch: IDO inhibitors in cancer therapy. Oncoimmunology. 2014 Dec 15;3(10):e957994. eCollection 2014 Nov. Review. PubMed PMID: 25941578; PubMed Central PMCID: PMC4292223.

2: Liu X, Shin N, Koblish HK, Yang G, Wang Q, Wang K, Leffet L, Hansbury MJ, Thomas B, Rupar M, Waeltz P, Bowman KJ, Polam P, Sparks RB, Yue EW, Li Y, Wynn R, Fridman JS, Burn TC, Combs AP, Newton RC, Scherle PA. Selective inhibition of IDO1 effectively regulates mediators of antitumor immunity. Blood. 2010 Apr 29;115(17):3520-30. doi: 10.1182/blood-2009-09-246124. Epub 2010 Mar 2. PubMed PMID: 20197554.

3: Koblish HK, Hansbury MJ, Bowman KJ, Yang G, Neilan CL, Haley PJ, Burn TC, Waeltz P, Sparks RB, Yue EW, Combs AP, Scherle PA, Vaddi K, Fridman JS. Hydroxyamidine inhibitors of indoleamine-2,3-dioxygenase potently suppress systemic tryptophan catabolism and the growth of IDO-expressing tumors. Mol Cancer Ther. 2010 Feb;9(2):489-98. doi: 10.1158/1535-7163.MCT-09-0628. Epub 2010 Feb 2. PubMed PMID: 20124451.

//////////1204669-58-8 , INCB024360, INCB24360, epacadostat, PHASE 2, CANCER, orphan drug designation

Fc1ccc(cc1Br)N/C(=N\O)c2nonc2NCCNS(N)(=O)=O

ASLAN Pharmaceuticals Gains Orphan Designation for Rare Cancer Drug ASLAN001 (varlitinib)

phase 2, Uncategorized Comments Off

Aug 242015

(R)-N4-[3-Chloro-4-(thiazol-2-ylmethoxy)-phenyl]-N6-(4-methyl-4,5-dihydro-oxazol-2-yl)-quinazoline-4,6-diamine

ASLAN001 , Varlitinib

C22H19ClN6O2S

Molecular Weight: 466.94

Elemental Analysis: C, 56.59; H, 4.10; Cl, 7.59; N, 18.00; O, 6.85; S, 6.87

CAS: 845272-21-1 (Varlitinib); 1146629-86-8 (Varlitinib tosylate).

ASLAN001; ASLAN-001; ASLAN 001; AR 00334543; ARRY-334543; ARRY334543; ARRY-543; ARRY543; ARRY 543.

(R)-N4-(3-chloro-4-(thiazol-2-ylmethoxy)phenyl)-N6-(4-methyl-4,5-dihydrooxazol-2-yl)quinazoline-4,6-diamine.

(R)-4-[[3-Chloro-4-[(thiazol-2-yl)methoxy]phenyl]amino]-6-[(4-methyl-4,5-dihydrooxazol-2-yl)amino]quinazoline

4,6-Quinazolinediamine, N4-[3-chloro-4-(2-thiazolylmethoxy)phenyl]-N6-[(4R)-4,5-dihydro-4-methyl-2-oxazolyl]-

ASLAN Pharmaceuticals, a Singapore-based drugmaker, announced The Food and Drug Administration (FDA) gave an orphan drug designation on August 13 to its pan-HER inhibitor ASLAN001 (varlitinib), a drug candidate created to treat a destructive form of bile duct cancer called cholangiocarcinoma that has no known cure. ………http://www.dddmag.com/news/2015/08/aslan-pharmaceuticals-gains-orphan-designation-rare-cancer-drug

Current developer: Array Biopharma Inc,

Varlitinib, also known as ARRY-543 and ASLAN001, is an orally bioavailable inhibitor of the epidermal growth factor receptor family with potential antineoplastic activity.

Varlitinib (ASLAN-001) is an oncolytic drug in phase II clinical trials at ASLAN Pharmaceuticals for the treatment of gastric cancer and for the treatment of metastatic breast cancer in combination with capecitabine. Clinical development is also ongoing for the treatment of solid tumors in combination with cisplatin/FU and cisplatin/capecitabine. The product had been in phase I/II clinical trials at Array BioPharma for the treatment of patients with advanced pancreatic cancer. Phase II clinical trials had also been ongoing for the treatment of solid tumors. No recent development has been reported for this research

Varlitinib selectively and reversibly binds to both EGFR (ErbB-1) and Her-2/neu (ErbB-2) and prevents their phosphorylation and activation, which may result in inhibition of the associated signal transduction pathways, inhibition of cellular proliferation and cell death. EGFR and Her-2 play important roles in cell proliferation and differentiation and are upregulated in various human tumor cell types. Due to the dual inhibition of both EGFR and Her-2, this agent may be therapeutically more effective than agents that inhibit EGFR or Her-2 alone.

The drug is a dual inhibitor of the ErB-2 and EGFR receptor kinases, both of which have been shown to stimulate aberrant growth, prolong survival and promote differentiation of many tumor types. The compound behaves as a reversible ATP-competitive inhibitor with nanomolar potency both in vitro and in cell-based proliferation assays.

In 2011, the compound was licensed to Aslan Pharmaceuticals by Array BioPharma worldwide for the treatment of solid tumors, initially targeting patients with gastric cancer through a development program conducted in Asia.

In 2015, orphan drug designation was assigned to the compound in the U.S. for the treatment of cholangiocarcinoma.

SEE NMR ………….http://www.medkoo.com/Product-Data/Varlitinib/Varlitinib-QC-KB20121128web.pdf

……………..

https://www.google.co.in/patents/US20050043334

Example 52

(R)-N4-[3-Chloro-4-(thiazol-2-ylmethoxy)-phenyl]-N6-(4-methyl-4,5-dihydro-oxazol-2-yl)-quinazoline-4,6-diamine

Prepared using (R)-2-aminopropan-1-o1. MS APCI (+) m/z 467, 469 (M+1, Cl pattern) detected; ¹H NMR (400 mHz, DMSO-D6) δ 9.53 (s, 1H), 8.47 (s, 1H), 8.09 (s, 1H), 7.86 (d, 1H), 7.81 (d, 1H), 7.77 (d, 1H), 7.69 (m, 3H), 7.32 (d, 1H), 7.02 (s, 1H), 5.54 (s, 2H), 4.47 (m, 1H), 3.99 (m, 1H), 3.90 (m, 1H), 1.18 (d, 3H).

Example 53

(S)-N4-[3-Chloro-4-(thiazol-2-ylmethoxy)-phenyl]-N6-(4-methyl-4,5-dihydro-oxazol-2-yl)-quinazoline-4,6-diamine

Prepared using (S)-2-amino-propan-1-o1. MS APCI (+) m/z 467, 469 (M+1, Cl pattern) detected; ¹H NMR (400 mHz, DMSO-D6) δ 9.53 (s, 1H), 8.47 (s, 1H), 8.09 (s, 1H), 7.86 (d, 1H), 7.81 (d, 1H), 7.77 (d, 1H), 7.69 (m, 3H), 7.32 (d, 1H), 7.02 (s, 1H), 5.54 (s, 2H), 4.47 (m, 1H), 3.99 (m, 1H), 3.90 (m, 1H), 1.18 (d, 3H).

………………

PATENT

http://www.google.co.in/patents/WO2005016346A1?cl=en

Example 52

R VN4-r3-Chloro-4-(^‘thiazol-2-v-metho-xy)-phenyll-N6-(4-methyl-4,5-dihvdro-oxazol- 2-yl)-quinazoUne-4,6-diamine

[00194] Prepared using (R)-2-aminopropan- 1 -ol. MS APCI (+) m/z 467, 469

(M+l, CI pattern) detected; 1H NMR (400 mHz, DMSO-D6) δ 9.53 (s, IH), 8.47 (s, IH), 8.09 (s, IH), 7.86 (d, IH), 7.81 (d, IH), 7.77 (d, IH), 7.69 (m, 3H), 7.32 (d, IH), 7.02 (s, IH), 5.54 (s, 2H), 4.47 (m, IH), 3.99 (m, IH), 3.90 (m, IH), 1.18 (d, 3H). Example 53

(S)-N4-|^“3-Chloro-4- thiazol-2-ylmethoxy)-phenyll-N6-(^‘4-methyl-4,5-dihvdro-oxazol- 2-yl)-quinazoline-4,6-diamine [00195] Prepared using (S)-2-amino-propan- 1 -ol. MS APCI (+) m z 467, 469

………

CAUTION a very similar molecule but not same

NOTE……..METHYL NEXT TO OXYGEN ATOM

Design, Synthesis and Bioactivities Evaluation of Novel Quinazoline Analogs Containing Oxazole Units

Xuehui Hou¹,
Jingyu Zhang²,
Xuan Zhao²,
Liming Chang²,
Ping Hu^1,* and
Hongmin Liu^3,*

DOI: 10.1002/cjoc.201400271,…………http://onlinelibrary.wiley.com/doi/10.1002/cjoc.201400271/abstract;jsessionid=04211D7526D97240F44E4355C6C57F50.f01t01

http://onlinelibrary.wiley.com/store/10.1002/cjoc.201400271/asset/supinfo/cjoc_201400271_sm_suppl.pdf?v=1&s=8dd0bf6d7ee4d3d6bf8503fef49bafc69220c931

CAUTION …THIS IS NOT SAME

A novel type of quinazoline derivatives, which were designed by the combination of quinazoline as the backbone and oxazole scaffold as the substituent, have been synthesized and their biological activities were evaluated for anti-proliferative activities and EGFR inhibitory potency. Compound 12b demonstrated the most potent inhibitory activity (IC₅₀=0.95 µmol/L for EGFR), which could be optimized as a potential EGFR inhibitor in the further study. The structures of the synthesized quinazoline analogs and all intermediates were comfirmed by ¹H and ¹³C NMR, 2D NMR spectra, IR spectra and MS spectra.

12c: Employing the same method as above, compound 12c was prepared and the amino alcohol was (S)-2-amino-propan-1-ol. Yellow solid, yield 52 %. m.p. 243-244 °C; [α] 20D =﹢22.5 ° (c 1.0, CH3CN); 1 H NMR (DMSO-D6): δ 9.54 (s, 1 H), 8.46 (s, 1 H), 8.06 (s, 2 H), 7.85 (d, 2 H, J=3.3 Hz), 7.79 (d, 2 H, J=3.3 Hz), 7.75 (d, 1 H, J=8.9 Hz), 7.64 (d, 1 H, J=8.3 Hz), 7.30 (d, 1 H, J=9.0 Hz), 5.54 (s, 2 H), 4.76 (m, 1 H), 3.72 (s, 1 H), 3.19 (s, 1 H), 1.34 (d, 3 H, J=6.15 Hz). 13C NMR (DMSO-D6) δ: 165.8, 156.9, 152.0, 148.8, 145.3, 142.6, 134.3, 128.7, 128.0, 123.5, 121.7, 121.3, 121.0, 115.6, 114.6, 72.5, 67.7, 63.0, 29.8, 29.0, 20.0, 13.9. IR (KBr) ν: 3439, 3278, 3101, 2925, 1660, 1631, 1601, 1557, 1500, 1428, 1404, 1384, 1329, 1291, 1257, 1225, 1052 cm-1. Anal. calcd for C22H19N6O2SCl: C 55.59, H 4.10, N 18.00, O 6.85; found C 55.55, H 4.13, N 18.02, O 6.78; MS (ESI) m/z: 467.2 (M+H).

12d: Employing the same method as above, compound 12d was prepared and the amino alcohol was (R)-2-amino-propan-1-ol. Yellow solid, yield 60%. m.p. 242-243 °C; [α] 20D = ﹣22.3 ° (c 1.0, CH3CN); 1 H NMR (DMSO-D6): δ 9.52 (s, 1 H), 8.80 (s, 1 H), 8.52 (dd, 1 H, J=2.7 Hz, J=8.9 Hz), 8.45 (s, 1 H), 8.30 (s, 1 H), 8.07 (s, 1 H), 7.85 (d, 1 H, J=3.2 Hz), 7.79 (d, 1 H, J=3.2 Hz), 7.75 (s, 1 H), 7.63 (d, 1 H, J=8.2 Hz), 7.31 (d, 1 H, J=9.0 Hz), 5.53 (s, 2 H), 4.76 (m, 1 H), 3.81 (s, 1 H), 3.19 (s, 1 H), 1.34 (d, 3 H, J=6.2 Hz). 13C NMR (DMSO-D6) δ: 165.8, 156.9, 152.0, 148.8, 145.3, 142.6, 134.3, 128.7, 128.0, 123.5, 121.7, 121.3, 121.0, 115.6, 114.6, 72.5, 67.7, 63.0, 29.8, 29.0, 20.0, 13.9. IR (KBr) ν: 3439, 3278, 3101, 2925, 1660, 1631, 1601, 1557, 1500, 1428, 1404, 1384, 1329, 1291, 1257, 1225, 1052 cm-1. Anal. calcd for C22H19N6O2SCl: C 55.59, H 4.10, N 18.00, O 6.85; found C 55.55, H 4.13, N 18.02, O 6.78; MS (ESI) m/z: 467.20 (M+H).

The above paper allows you to synthesize the key amino int 11 ………N4-(3-chloro-4-(thiazol-2-ylmethoxy)phenyl)quinazoline-4,6-diamine (11)

this can be applied to varlitinib till int 11

6-Nitro-4-hydroxyquinazoline (3)

2-amino-5-nitrobenzoic acid (5.46 g, 30 mmol) was added to a 250 mL flask equipped with a reflux condenser. Then 50 mL formamide was added. The mixture was heated with vigorous stirring at 160 °C for 3 h. After cooling the solution was poured in ice-water to give 3 in almost pure form (Yellow solid 4.70 g, yield 82.0%). m.p. 317-318 °C; 1 H NMR (DMSO-d6): δ 12.74 (1 H, s, OH, exchangeable), 8.78 (1 H, d, J=2.4 Hz), 8.53 (1 H, dd, J=2.6 Hz, 9.0 Hz), 8.30 (s, 1 H), 7.84 (1 H, d, J=9.0 Hz); 13C NMR (DMSO-d6) δ: 160.1, 152.9, 148.9, 145.0, 129.1, 128.3, 122.7, 121.9. IR (KBr) ν: 3172, 3046, 2879, 1674, 1615, 1577, 1514, 1491, 1469, 1343, 1289, 1242, 1167, 1112, 928, 920, 901, 803, 753, 630, 574, 531 cm-1. Anal. calcd for C8H5N3O3: C 50.27, H 2.64, N 21.98; found C 50.30, H 2.65, N 21.96; MS (ESI) m/z: 189.97 (M-H).

13C NMR OF 3 IN DMSOD6

4-chloro-6-Nitroquinazoline (4)

In a 100 mL flask equipped with a reflux condenser, 6-nitroquinazolin-4-one (2.86 g, 15 mmol) and thionyl chloride (SOCl2) 25 mL were added. The mixture was heated under reflux with vigorous stirring for 2 h. After the solution was clear, the reaction mixture was heated for another 2 h. Then, 150 mL of ice MeOH was dropped into it carefully, the mixture was extracted with CH2Cl2. The organic layer was S3 dried under MgSO4, filtered and the solvent removed to give 4-chloro-6-nitroquinazoline (4). Yellow solid 2.45 g, yield 78%. m.p. 134-135 °C; 1 H NMR (DMSO-d6): δ 8.80 (1 H, d, J=3.0 Hz), 8.54(1 H, dd, J=2.7 Hz, 9.0 Hz), 8.35(s, 1 H), 7.87 (1 H, d, J= 9.0 Hz); 13C NMR (DMSO-d6) δ: 160.0, 152.5, 149.1, 145.1, 128.7, 128.4, 122.7, 122.0. IR (KBr) ν: 3431, 3082, 3038, 2664, 2613, 2567, 1724, 1685, 1676, 1646, 1617, 1578, 1526, 1468, 1359, 1346, 1269 cm-1. Anal. calcd for C8H4N3O2Cl: C 45.84, H 1.92, N 20.05, O 15.27; found C 45.81, H 1.97, N 20.02, O 15.21; MS (ESI) m/z: 207.96 (M-H).

nmr1 4 nmr dmsod6

13C NMR OF4 IN DMSOD6

Thiazol-2-yl-methano1 (6)

Sodium borohydride (16.0 g, 140 mmol) was added to a stirred solution of thiazole-2-carbaldehyde (24.2 g, 214 mmol) in MeOH (400 mL) at 0 °C . The reaction mixture was warmed to room temperature. After 1 hour, the reaction mixture was quenched by the addition of water and the organics were removed by concentration. The resulting aqueous mixture was extracted with EtOAc. The combined organic extracts were dried under Na2SO4 and concentrated to give thiazol-2-yl-methano1 (23.39 g, 95%). bp:75-76 °C (0.2 mmHg) [lit.[19] bp:70-80 °C (0.2 mmHg)]; m. p. 63-64 °C. 1 H NMR (CDCl3) δ 4.91 (s, 2 H), 5.1(br, l H), 7.28(d, 1 H, J=3.2 Hz), 7.68 (d, 1 H, J=2.9 Hz). IR (KBr) ν: 3135, 3099, 3082, 2814, 1509, 1446, 1351, 1189, 1149, 1073, 1050, 977, 775, 745, 613, 603 cm-1. Anal. calcd for C4H5NOS: C 41.72, H 4.38, N 12.16; found C 41.74, H 4.33, N 12.18; MS (ESI) m/z: 116.11 (M+H).

nmr1 6 in dmsod6 1H NMR

2-((2-Chloro-4-nitrophenoxy)methyl)thiazole (8)

2-(2-chloro-4-nitro-phenoxymethy1)-thiazole was prepared by adding thiazol-2-yl-methanol (5.48 g, 47.65 mmol) to a slurry of sodium hydride (2.42 g of a 60% dispersion in oil, 60.5 mmol) in THF (50 ml) at 0 °C After several minutes, 2-chloro-1-fluoro- 4-nitro-benzene (7.58 g, 43.60 mmol) was added and the reaction mixture warmed to room temperature. The reaction mixture was stirred at room temperature for 3 h, and 60 °C for 16 h. After cooling to room temperature, the reaction mixture was poured into 300 mL water. The resulting precipitate was collected by filtration, washed with water, and dried in vacuo to give 2-(2- chloro-4-nitrophenoxymethy1)-thiazole (11.06 g, 86%) which was used in next step without further purification. m.p. 170-171 °C; 1 H NMR (DMSO-d6): δ 8.35 (1 H, d, J=2.8 Hz), 8.25 (1 H, dd, J=2.8 Hz, 9.15 Hz), 7.87 (1 H, d, J=3.3 Hz), 7.83(1 H, d, J=3.3 Hz), 7.54 (1 H, d, J=9.2 Hz), 5.73(s, 1 H); 13C NMR (DMSO-d6) δ: 164.2, 158.5, 143.2, 141.7, 125.9, 124.9, 122.4, 122.2, 114.6, 68.4; IR (KBr) ν: 3112, 3009, 1587, 1509, 1500, 1354, 1319, 1284, 1255, 1154, 1125, 1054, 1006, 894, 780, 746, 728 cm-1. Anal. calcd for C10H7N2O3SCl: C 44.37, H 2.61, N 10.35, O 17.73; found C 44.31, H 2.67, N 10.29; MS (ESI) m/z: 268.89 (M-H).

1H NMR 8 DMSOD6

13C NMR OF 8 IN DMSOD6

3-Chloro-4-(thiazol-2-ylmethoxy)aniline (9)

In a flask equipped with a reflux condenser, the compound 8 15.00 g (55.6 mmol), reduced zinc powder 14.44 g (222.0 mmo1, 4 eq), saturated ammonia chloride (5 mL) and methanol (100 mL) were mixed. The mixture was stirred at a temperature of 40 °C for 1.5 h. Then the zinc powder was filtered off, the filtrate was concentrated to obtain yellow solid 13.21 g, yield 99%. m.p. 60-61 °C; 1 H NMR (DMSO-d6): δ 7.80 (1 H, d, J=3.3 Hz), 7.75 (1 H, d, J=3.3 Hz), 6.96 (1 H, d, J=8.8 Hz), 6.64(1 H, d, J=2.7 Hz), 6.46 (1 H, dd, J=2.7 Hz, J=8.7 Hz), 5.30 (s, 2 H), 5.04 (s, 2 H, NH2, exchangeable); 13C NMR (DMSO-d6) δ: 166.8, 145.1, 144.1, 142.80, 123.1, 121.5, 117.7, 115.2, 113.6, 69.1. IR (KBr) ν: 3322, 3192, 3112, 1607, 1499, 1457, 1436, 1291, 1274, 1221, 1191, 1144, 1057, 1027, 857, 797, 767, 733, 584 cm-1. Anal. calcd for C10H9N2OSCl: C 49.90, H 3.77, N 11.64, O 6.65; found C 49.95, H 3.76, N 11.66, O 6.60; MS (ESI) m/z: 239.01 (M-H).

1H NMR DMSOD6 OF 9

13C NMR OF 9 IN DMSOD6

N-(3-chloro-4-(thiazol-2-ylmethoxy)phenyl)-6-nitro- quinazolin-4-amine（10）

In a flask equipped with a reflux condenser, 6-nitro-4-chloro- quinazoline 8.0 g (38.3 mmol) and 3-Chloro-4-(thiazol-2-ylmethoxy)aniline 8.9 g (37.0 mmol) were dissolved into 150 mL of THF, and the solution was refluxed for 3 h.Then a lot of yellow solid was deposited. Then it was filtered affording to yellow solid 12.8 g, yield 81%. m.p. 183-184 °C (decompose); 1 H NMR (DMSO-d6): δ 11.97(s, 1 H, exchangeable), 9.84 (s, 1 H), 9.00 (s, 1 H), 8.76 (1 H, d, J=9.1 Hz), 8.12-8.14 (m, 1 H), 7.94 (1 H, d, J=2.3 Hz), 7.87 (1 H, d, J=3.2 Hz), 7.81 (1 H, d, J=3.2 Hz), 7.44 (1 H, d, J=9.0 Hz), 7.69 (1 H, dd, J=2.5 Hz, J=8.9 Hz), 5.61 (s, 2 H); 13C NMR (DMSO-d6) δ: 166.8, 145.1, 144.1, 142.8, 123.1, 121.5, 117.7, 115.2, 113.7, 69.1. IR (KBr) ν: 3442, 3100, 1636, 1618, 1570, 1552, 1523, 1492, 1442, 1400, 1377, 1344, 1301, 1267, 1069, 805 cm-1. Anal. calcd for C18H12N5O3SCl: C 52.24, H 2.92, N 16.92, O 11.60; found C 52.26, H 2.93, N 16.96, O 11.58; MS (ESI) m/z: 412.84 (M-H).

1H NMR DMSOD6 OF 10

13C NMR OF 10 IN DMSOD6

N4-(3-chloro-4-(thiazol-2-ylmethoxy)phenyl)quinazoline-4,6-diamine (11)

In a flask equipped with a reflux condenser, the compound 10 5.00 g (12.1 mmol), reduced zinc powder 3.2 g (48.5 mmo1, 4 eq), saturated ammonia chloride (3 mL) and methanol (60 mL) were mixed. The mixture was stirred at room temperature for 30 min. Then the zinc powder was filtered off, the filtrate was concentrated to obtain yellow solid 4.58 g, yield 98%. m.p. 197-198 °C (decompose); 1 H S4 NMR (DMSO-d6): δ 9.33(s, 1 H, exchangeable), 8.31 (s, 1 H), 8.05 (d, 1 H, J=2.6 Hz), 7.85 (d, 1 H, J=3.3 Hz), 7.79 (1 H, d, J=3.3 Hz), 7.73 (1 H, dd, J=2.5 Hz, J=9.0 Hz), 7.51 (1 H, d, J=8.9 Hz), 7.30 (1 H, d, J=2.4 Hz), 7.29 (1 H, d, J=4.7 Hz), 7.23 (1 H, dd, J=2.3 Hz, J=8.9 Hz), 5.57 (s, 2 H, exchangeable), 5.52 (s, 2 H); 13C NMR (DMSO-d6) δ: 165.9, 155.8, 149.7, 148.5, 147.3, 142.6, 142.5, 134.6, 128.7, 123.6, 123.2, 121.4, 121.3, 121.1, 116.5, 114. 7, 100.9, 67.8. IR (KBr) ν: 3443, 3358, 3211, 3100, 1631, 1596, 1577, 1560, 1530, 1494, 1431, 1383, 1217, 910 cm-1. Anal. calcd for C18H14N5OSCl: C 56.32, H 3.68, N 18.24, O 4.17; found C 56.34, H 3.70, N 18.22, O 4.14; MS (ESI) m/z: 382.66 (M-H).

11 1HNMR DMSOD6

13C NMR OF 11 IN DMSOD6

Construction finally as per patent ……….US20050043334

Treatment of N4-[3-chloro-4-(thiazol-2-ylmethoxy)phenyl]quinazoline-4,6-diamine (11) with 1,1′-thiocarbonyldiimidazole , followed by condensation with 2(R)-amino-1-propanol in THF/CH2Cl2 affords thiourea derivative , which finally undergoes cyclization in the presence of TsCl and NaOH in THF/H2O to furnish varlitinib .