LUPIN LIMITED, WO 2016181313, NEW PATENT, SOFOSBUVIR

WO2016181313,  A PROCESS FOR THE PREPARATION OF SOFOSBUVIR INTERMEDIATES & ITS POLYMORPH

LUPIN LIMITED [IN/IN]; Kalpataru Inspire 3rd Floor, Off Western Express Highway Santacruz (East) Mumbai 400 055 (IN)

SINGH, Girij, Pal; (IN).
SRIVASTAVA, Dhananjai; (IN).
MEHARE, Kishor, Gulabrao; (IN).
MALIK, Vineet; (IN).
DEOKAR, Sharad, Chandrabhan; (IN).
DANGE, Abhijeet, Avinash; (IN)

SUCCESS QUOTIENT: Lupin chairman DB Gupta (sitting) with managing director Kamal K Sharma (centre), directors Vinita Gupta (right) and Nilesh Gupta.

The present invention provides a novel process for preparation N-[(2,3,4,5,6- Pentafluorophenoxy)phenoxyphosphinyl]-L-alanine 1-methylethyl ester (formula 2) and resolving the formula 2 in the presence base to form N-[(S)-(2,3,4,5,6- Pentafluorophenoxy)phenoxyphosphinyl]-L-alanine 1-methylethyl ester (formula 2').

Sofosbuvir is chemically named as (S)-isopropyl 2-((S)-(((2R,3R,4R,5R)-5-(2,4- dioxo3,4-dihydropyrimidin-l(2H)-yl)-4-fluoro-3-hydroxy-4-methyltetrahydrofuran- 2yl)methoxy)-(phenoxy)phosphorylamino)propanoate and is represented by the following chemical structure:

Formula 1

PCT publications WO2011123645 and WO2010135569 describes process for preparation of compound of formula 2' by reacting isopropyl (chloro(phenoxy)phosphoryl)-L-alaninate and pentaflurophenol in the presence of base.

Formula 2'

Example-1:

Preparation of sodium 2,3,4,5,6-pentaflurophenolate using sodium hydride

10.2g of sodium hydride was dissolved in 100 ml anhydrous THF. This solution was slowly added to a solution of pentafluorophenol (50g) in THF (100ml), Reaction mass was stirred for 60-120 min at 25-30°C. Reaction mass was distilled under reduced pressure, obtained solid was dried under vacuum at 45-50°C (yield=55g, confirmed by IR)

Example-2:

Preparation of sodium 2,3,4,5,6-pentaflurophenolate using sodium methoxide

2,3,4,5, 6-pentafluorophenol (lOg) was dissolved in methanol (100ml), solution was cooled to 5-10°C. To this was added a solution of sodium methoxide in methanol. The reaction mass was stirred for 60-120 min at 25-30°C. Reaction mass was distilled under reduced pressure, obtained residue was striped with toluene. Obtained solid was dried under vacuum at 45-50°C (yield=l lg)

Example 3:

Preparation of sodium 2,3,4,5,6-pentaflurophenolate using sodium hydroxide

2,3,4,5, 6-pentafluorophenol (lOOg) dissolved in methanol (—ml), solution was cooled to 5-10°C. To this was added a solution of sodium hydroxide (— g) in methanol. The reaction mass was stirred for 60-120 min at 25-30°C. Reaction mass was distilled under reduced pressure, obtained residue was striped with dichloromethane. Obtained solid was dried under vacuum at 45-50°C (yield=— g)

Example 4:

Preparation of (2S)-isopropyl-2-((chloro(phenoxy)posphoryl)amino)propanoate:

phenyl phosphodichloridate (30.6g) was dissolved in dichloromethane , to this was added a solution of 1-alanine isopropyl ester free base (19.16g) in dichloromethane at-60°C under nitrogen. Solution of triethylamine (20.7ml) was added to above reaction mass. Reaction mass was stirredat -60°C for 30 min and then temperature was raised to 25 °C. Reaction mass was stirred at 20-25 °C for 60 min & filtered and washed with dichloromethane. Clear filtrate was distilled under reduced pressure obtained residue was stirred with diisopropyl ether & filtered. Clear filtrate was distilled under reduced pressure to get (2S)-isopropyl-2-((chloro(phenoxy)posphoryl)amino)propanoate compound.

Example 5:

Preparation of isopropyl ((perfluorophenoxy)(phenoxy)phosphoryl)-L-alaninate (formula 2):

(Formula 2)

Obtained (2S)-isopropyl-2-((chloro(phenoxy)phosphoryl)amino)propanoate (1.2 mol eq.) was dissolved in dichloromethane and cooled to 0-5°C under nitrogen atmosphere. To this was added solution of sodium 2,3,4,5,6-pentaflurophemolate (1 mol eq.) in tetrahydrofuran . Temperature of reaction mass was raised to 25°C and reaction mass was stirred for 3 hrs. After completion of reaction, reaction mass was distilled under reduced pressure & obtained residue was dissolved I ethyl acetate. Ethyl acetate layer was washed with water, dried over sodium sulfate & distilled off under reduced pressure. Diisopropyl ether was added to obtained residue and stirred for 60 min at 25 °C, obtained mass was filtered & washed with diisopropyl ether. Solid product was dried under vacuum at 40-45 °C .(yield=20g, enantiomer purity=93.45%)

Example 6:

Preparation of (S)-isopropyl 2-(((S)- (perfluorophenoxy)phenoxy)phosphoyl)amino)propanoate (Formula 2'):

Formula 2'

(2S)-isopropyl-2-((chloro(phenoxy)phosphoryl)amino)propanoate (1.2 mol eq.) was dissolved in tetrahydrofuran (3.5 volumes). The reaction mass was cooled to -10°C. Solution of sodium salt of pentafluorophenol (1 mol eq.) in tetrahydrofuran (3.5 volumes) was added dropwise to the reaction mass at -10°C. After completion of the reaction solvent was distilled off. Ethyl acetate and water were added to the reaction mass. Reaction mass was stirred, ethyl acetate layer was separated and washed with sodium bicarbonate solution and brine. Ethyl acetate layer was concentrated under reduced pressure. Reaction mass was stripped with n-hepatane to get crude product. Crude product was dissolved in Methyl tert-butyl ether and n-heptane (1 : 1 ratio). The pH of reaction mass was adjusted to pH 8 by using triethylamine. Reaction mass was stirred overnight. Solid mass was filtered and washed with a mixture of methyl tertiary-butyl ether: n-heptane (1 : 1). The obtained product was dissolved in ethyl-acetate and washed with water and 20% brine solution. Ethyl acetate layer was separated; solvent was distilled off under reduced pressure. Reaction mass was stripped with diisopropyl ether. Di-isopropyl ether was added to the reaction mass. Reaction mass was stirred at 45-50°C. Reaction mass was cooled to 5-10°C and stirred. The titled compound was isolated by filtration and washed with di-isopropyl ether. The titled compound was dried under reduced pressure at 40°C. Yield 66.81%.

Vinita Gupta, CEO, Lupin Pharmaceuticals Inc

Desh Bhandu Gupta- Founder and chairman of Lupin Limited

////////////LUPIN LIMITED, WO 2016181313,  NEW PATENT, SOFOSBUVIR

LUPIN, SOFOSBUVIR, NEW PATENT, WO 2016016865

(WO2016016865) A PROCESS FOR THE PREPARATION OF NUCLEOSIDE PHOSPHORAMIDATE

LUPIN LIMITED [IN/IN]; 159 CST Road, Kalina, Santacruz (East), State of Maharashtra, Mumbai 400 098 (IN)

ROY, Bhairab, Nath; (IN).
SINGH, Girij, Pal; (IN).
SHRIVASTAVA, Dhananjai; (IN).
MEHARE, Kishor, Gulabrao; (IN).
MALIK, Vineet; (IN).
DEOKAR, Sharad, Chandrabhan; (IN).
DANGE, Abhijeet, Avinash; (IN)

The present invention pertains to process for preparing nucleoside phosphoramidates and their intermediates. Phosphoramidates are inhibitors of RNA-dependent RNA viral replication and are useful as inhibitors of HCV NS5B polymerase, as inhibitors of HCV replication and for treatment of hepatitis C infection in mammals. One of the recently approved phosphoramidate by USFDA is Sofosbuvir [1190307-88-0]. Sofosbuvir is a component of the first all-oral, interferon-free regimen approved for treating chronic hepatitis C. The present invention provides novel intermediate, its process for preparation and use for the preparation of Sofosbuvir. The present invention also gives one pot process for preparation of Sofosbuvir.

Hepatitis C virus (HCV) infection is a major health problem that leads to chronic liver disease, such as cirrhosis and hepatocellular carcinoma, in a substantial number of infected individuals. There are limited treatment options for individuals infected with hepatitis C virus. The current approved therapeutic option is the use of immunotherapy with recombinant interferon- [alpha] alone or in combination with the nucleoside analog ribavirin.

US 7964580 ('580) is directed towards novel nucleoside phosphoramidate prodrug for the treatment of hepatitis C virus infection.

US'580 patent claims Sofosbuvir and rocess for preparation of Sofosbuvir of Formula 1.

Formula 1

Process for preparation of Sofosbuvir as per US '580 patent involve reaction of compound of Formula 4" with a nucleoside 5'

Compound 4" nucleoside 5'

Wherein X' is a leaving group, such as CI, Br, I, tosylate, mesylate, trifluoroacetate, trifluroslfonate, pentafluorophenoxide, p-nitro-phenoxide.

Objects of the invention

The object of the present invention is to provide a novel intermediate of Formula 2

Formula 2

wherein X' is a leaving group selected from 1-hydroxybenzotriazole, 5-(Difluoromethoxy)-lH-benzimidazole-2-thiol, 2-Mercapto-5-methoxybenzimidazole, cyanuric acid, 2-oxazolidinone, 2-Hydroxy Pyridine. The above leaving group can be optionally substituted with n-alkyl, branched alkyl, substituted alkyl; cycloalkyl; halogen; nitro; or aryl, which includes, but not limited to, phenyl or naphthyl, where phenyl or naphthyl are further optionally substituted with at least one of Ci-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, Ci-C₆ alkoxy, F, CI, Br, I, nitro, cyano, Ci-C₆ haloalkyl, -N(R^r)2, Ci-C₆ acylamino, -NHS0₂Ci-C₆ alkyl, -S0₂N(R^r)₂, COR^1", and -S0₂Ci-C₆ alkyl; (R^r is independently hydrogen or alkyl, which includes, but is not limited to, Ci-C₂o alkyl, Ci-Cio alkyl, or Ci-C₆ alkyl, R¹" is -OR¹ or -N(R^r)₂).

Another object of the present invention is to provide a process to prepare the intermediate of Formula 2.

Another object of the present invention is use of the intermediate of Formula 2 in the preparation of Sofosbuvir of Formula 1.

Formula 1

Example 1:

Process for the preparation of S-oxazolidinone derivative of Formula 2

Step-1 Preparation of phosphorochloridate solution:

Dichloromethane (DCM 400ml) was charged in round bottom flask flushed with nitrogen. Phenyl phosphodichloridate (18.30ml) was added in one portion in the flask. The flask was cooled to -60°-70°C with a dry ice-acetone bath. Solution of L-alanine isopropyl ester hydrochloride (20.6gm)) in DCM (50ml) was added to the reaction flask. To this was added a solution of triethylamine (11.20ml) in MDC (100 ml) was added over a course of 60 minutes, while maintaining internal temperature below -70 °C throughout the addition. After completion of reaction, temperature of reaction mass was raised to room temperature.

100ml THF was charged in another round bottom flask flushed with nitrogen followed by the addition of S-4-phenyloxazolidnone (lOgm). Triethyl-amine (11.2ml) & LiCl (2.85gm) were added to the above flask. The reaction mass was stirred for 15-30 min at room temperature and was cooled to 0-5 °C. Phosphorochloridate solution from step-1 was added drop- wise to the reaction flask in 15-45 min maintaining reaction temperature at 0-5 °C. The reaction mass was stirred for 30-60min at 0°-5°C. The reaction progress was monitored on thin layer chromatography. After completion of the reaction, the reaction temperature was raised to room temperature. Agitation was resumed for an additional 30min. The reaction mass was filtered and concentrated under reduced pressure. To this was added diisopropyl ether (400ml) and aqueous saturated ammonium chloride solution and reaction mass was stirred for 10-15 minutes. Organic layer was separated and was washed with water (100ml) & dried over sodium sulfate and concentrated under vacuum. Cyclohexane (50ml) was charged to the obtained oily mass and reaction mass was stirred till solid precipitated out. Solid was filtered and washed with cyclohexane and dried under vacuum (8.80gm MP 56.5°-56.6°C). The obtained product was characterized by mass, NMR & IR. 1H NMR (DMSO-d₆) δ 1.142 -1.18

(m, 9H), 3.85-3.92 (m, 1H), 4.72-4.89(m, 2H), 5.31-5.32(d, 1H), 6.25-6.3 (m, 1H), 6.95-7.31 (m, 10H); MS, m/e 433 (M+l) ⁺

Example 2: Process for the preparation of 2-hydroxy pyridine derivatives of formula 2:

Anhydrous dichloromethane (DCM) 700ml was charged in round bottom flask flushed with nitrogen. The flask was cooled to -60° to -70°C in a dry ice acetone bath. Phenyl phosphodichloridate (76.04 gm) was added in one portion in the flask at -65°C. Solution of L-alanine isopropyl ester hydrochloride (60.56 gm) in DCM (50 ml) was added to the reaction mass. Solution of triethylamine (72.44gm) in DCM (50ml) was added to the reaction mass over a course of 60 minutes, while maintaining internal temperature below -70°C throughout the addition. The resulting white slurry was agitated for additional 60 minutes. Then the temperature of reaction mass was raised to room temperature. Reaction mass was stirred for 60 min & TLC was checked. Reaction mass was filtered and rinsed with anhydrous dichloromethane (2 XI 00 mL). The filtrate was concentrate under vacuum to 20 V and reaction mass was filtered, washed with DCM (15ml). The filtrate was transferred to RBF. The reaction mass was cooled to 0°-10°C. A solution of 2-hydroxy-3-nitro-5- (trifluoromethyl) pyridine (15.gm) in DCM (100ml) & triethyl amine (21.89gm) was added to the reaction mass. Temperature of reaction mass was raised to 20-30°C. Reaction mass was stirred overnight. Reaction was monitored using TLC. After completion, the reaction mass was filtered and washed with DCM (30ml). Filtrate was washed with water (150 ml x 2). Organic layer was concentrated under vacuum and degased. Diisopropyl ether (200ml) was charged to reaction mass and reaction mass was stirred for 15 minutes , filtered and washed with methyl ter-butyl ether (MTBE 30ml). Filtrate was concentrated under vacuum and dried. (8.68gm, MP-125.5°-131.5°C). Obtained compound was characterized by Mass, NMR & IR. 1H NMR (DMSO-d₆) δ 1.07 -1.27 (m, 9H), 4.04-4. l l(m, 1H), 4.73-4.79(m, 1H), 6.76-7.43 (m, 5H), 9.00-9.02 (d, 2H); MS, m/e 478 (M+l) ⁺; FTIR, 1203, 1409, 1580, 1732, 3217.

Other 2-hydroxy pyridine derivatives of Formula 2 were prepared by following the process disclosed in example 2-

2-Hydroxy-5-fluoropyridine derivative of Formula 2;-1H NMR (DMSO-d₆) δ 1.09 -1.23 (m, 9H), 3.02-3.06 (m, lH), 3.85-4.01 (m,lH), 4.79-4.87(m, 1H), 6.4-6.52 (m,lH), 7.10-7.89 (m,6H); MS, m/e 383 (M+l) ⁺,

2-Hydroxy-5-nitropyridine derivative of Formula 2:- 1H NMR (DMSO-d₆) δ 1.06 -1.22 (m, 9H),4.0-4.02 (m,lH), 4.7-4.8(m,lH), 6.5-6.6 (m,lH),7.12-7.42 (m,6H),8.66-8.68 (d, lH),9.07-9.13(d,lH); MS, m/e 410 (M+l) ⁺

2-Hydroxy-3, 5-dinitropyridine derivative of Formula 2:- 1H NMR (DMSO-d₆) δ 1.11 -1.24 (m, 9H), 3.04-3.09(m,lH), 4.8-4.86(m,lH), 7.09-7.39 (m,5H),8.97-9.06 (d,2H)

Example 3: Process for the preparation of Sofosbuvir by coupling of isopropyl(((3-nitro-5-(trifluromethyl)pyridin-2-yl)oxy)phenoxy)phosphoryl-L-alaninate with 1-((2R,3R,4R,5R)-3-fluoro-4-hydroxy-5-(hydroxymethyl)-3-methyltetrahydrofuran-2-yl)pyrimidine-2,4(lH,3H)-dione :

To a solution of l-((2R,3R,4R,5R)-3-fluoro-4-hydroxy-5-(hydroxymethyl)-3-methyltetrahydrofuran-2-yl)pyrimidine-2,4(lH,3H)-dione (0.2gm) in THF (4 ml), tert- butylmagnesium chloride (0.80ml, 1.7 M solution in THF) was added dropwise at room temperature and reaction mass was stirred for 30 minutes. A solution of pyridine derivative from example 2 (0.36gm) in THF (4ml) was added dropwise to the reaction mass at room temperature. Completion of reaction was monitored using TLC. After completion of reaction, reaction mass was quenched by using saturated ammonium chloride solution (10ml). Reaction mass was extracted with ethyl acetate (50ml). Organic layer was separated, dried over magnesium sulfate and concentrated under vacuum. The resulting residue was purified by column chromatography on silica gel & obtained solid product was characterized. MS, m/e 530.2 (M+l) ⁺.

/////////LUPIN, SOFOSBUVIR, NEW PATENT, WO 2016016865

NEW PATENT WO2015188782, METHOD FOR PREPARING SOFOSBUVIR

 

SOFOSBUVIR

NEW PATENT WO2015188782,

 (WO2015188782) METHOD FOR PREPARING SOFOSBUVIR

CHIA TAI TIANQING PHARMACEUTICAL GROUP CO., LTD [CN/CN]; No. 8 Julong North Rd., Xinpu District Lianyungang, Jiangsu 222006 (CN)
 




Sofosbuvir synthesis routes currently used include the following two methods:



https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2015188782&redirectedID=true

 

Preparation Example 1 sofosbuvir implementation

[0067]

[0068]

Step (a):

[0069]

At 0 ℃, dichloro-phenyl phosphate (6.0g, 28.4mmol) in dry dichloromethane (30ml) and stirred added alanine isopropyl ester hydrochloride (4.8g, 28.4mmol), the mixture After stirring and cooling to -55 ℃, was slowly added dropwise triethylamine (6.5g, 64mmol) and dichloromethane (30ml) mixed solution, keeping the temperature during at -55 ℃, dropping was completed, stirring was continued for 60 minutes, after liters to -5 ℃ stirred for 2 hours, TLC monitored the reaction was complete. To remove triethylamine hydrochloride was filtered and the filtrate evaporated under reduced pressure to give compound 3-1 as a colorless oil (Sp / Rp = 1/1).

[0070]

³¹ PNMR (CDCl ₃ , 300 Hz, H ₃ PO ₄ as internal standard): δ8.25 & 7.94 (1: 1);

[0071]

¹ HNMR (CDCl ₃ , 300 MHz): δ7.39-7.34 (m, 2H), 7.27-7.18 (m, 3H), 5.10-5.02 (m, 1H), 4.51 (br, 1H), 4.11 (m, 1H ), 1.49 (d, 3H), 1.29-1.24 (m, 6H);

[0072]

¹³ C NMR (CDCl ₃ , 300 MHz): δ172.1 (Rp), 196.3 (Sp), 129.8,129.6 (d), 125.9,120.5 (d), 69.7 (d), 50.7 (d), 21.6 (d), 20.4 (d).

[0073]

Step (b):

[0074]

At 5 ℃, the compound of formula 2 (5.20g, 20.0mmol) in dry THF (30ml) and stirred at t-butyl chloride (1.0M THF solution, 42ml, 42.0mmol). The reaction temperature was raised to 25 ℃, and the mixture was stirred for 30 minutes. After addition of lithium chloride (21.0mmol), was slowly added dropwise the compound 3-1 (approximately 28.4mmol) and THF (30ml) mixed solution, keeping the temperature during at 5 ℃. Bi drops, stirred for 15 hours. With aqueous 1N HCl (25ml) The reaction solution was quenched (HPLC assay Sp: Rp ratio of 4: 1). Toluene was added (100ml), temperature was raised to room temperature. The organic layer was washed with 1N HCl, water, 5% Na ₂ CO ₃ and washed with brine, dried over anhydrous magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure to a solid, was added methylene chloride (20ml), stirred for 5 minutes plus isopropyl ether, stirring was continued for 2 hours, the precipitated solid was filtered off. The solid was dissolved by heating in dichloromethane (60ml), slowly cooled to room temperature and the precipitated crystalline solid. Repeat if necessary obtain pure crystalline sofosbuvir (2.6g, yield 25%, HPLC purity measured 98.8%).

[0075]

³¹ PNMR (CDCl ₃ , 300 Hz, H ₃ PO ₄ as internal standard): δ3.54ppm;

[0076]

¹³ C NMR (CDCl ₃ , 300 Hz): δ173.1 (d), 162.7 (s), 150.2 (d), 139.3 (d), 129.6 (q);

[0077]

MS (M + H): 530.1.

[0078]

Preparation of compounds of formula 2 shown in Example 3-2

[0079]

[0080]

(1) a nucleophilic reagent as NaSCN, the phase transfer catalyst is TBAB

[0081]

The compound (product of Example 1, step (a)) is represented by the formula 3-1 is dissolved in dichloromethane (20ml) was added TBAB (2.8mmol), the NaSCN (35mmol) in water (2.0ml) was added dropwise It was added to the reaction solution. Dropping was completed, stirring was continued for 60 minutes, the solid was removed by filtration. The filtrate was washed with water, add MgSO ₄ dried for 24 hours. Filtered, and the filtrate was evaporated under reduced pressure, to obtain a compound of formula 3-2 as (where X = SCN).

[0082]

¹ HNMR (CDCl ₃ , 500Hz): δ7.32-7.13 (m, 3H), 7.08-7.02 (m, 2H), 5.0-4.9 (m, 1H), 3.92 (m, 1H), 1.49 (m, 3H ), 1.23-1.17 (m, 6H);

[0083]

³¹ PNMR (CDCl ₃ , 300 Hz, H ₃ PO ₄ internal standard): δ-18.16 / -18.26.

[0084]

(2) nucleophile NaSCN, phase transfer catalyst is 18-crown-6 ether

[0085]

The compound (product of Example 1, step (a)) is represented by the formula 3-1 is dissolved in ethyl acetate (20ml) was added 18-crown -6 (2.8mmol), the NaSCN (35mmol) was added to the above the reaction mixture. Dropping was completed, stirring was continued for 60 minutes, the solid was removed by filtration. The filtrate was washed with water, add MgSO ₄ dried for 24 hours. Filtered, and the filtrate was evaporated under reduced pressure, to obtain a compound of formula 3-2 as (where X = SCN).

[0086]

(3) nucleophile NaSCN, phase transfer catalyst is TBAB and 18-crown-6

[0087]

The compound (product of Example 1, step (a)) is represented by the formula 3-1 is dissolved in dichloromethane (20ml) was added TBAB (2.8mmol) and 18-crown -6 (2.8mmol), the NaSCN (35mmol) in water (2.0ml) was added to the reaction solution. Dropping was completed, stirring was continued for 60 minutes, the solid was removed by filtration. The filtrate was washed with water, add MgSO ₄ dried for 24 hours. Filtered, and the filtrate was evaporated under reduced pressure, to obtain a compound of formula 3-2 as (where X = SCN).

[0088]

(4) nucleophile as NaN ₃ , phase transfer catalyst is TBAB

[0089]

The compound (product of Example 1, step (a)) is represented by the formula 3-1 is dissolved in dichloromethane (20ml) was added TBAB (2.8mmol), the NaN ₃ (35 mmol) in water (2.0ml) solution of was added dropwise to the reaction solution. Dropping was completed, stirring was continued for 60 minutes, the solid was removed by filtration. The filtrate was washed with water, add MgSO ₄ dried for 24 hours. Filtered, and the filtrate was evaporated under reduced pressure, to obtain a compound of formula 3-2 as (where X = N ₃ ).

[0090]

¹ HNMR (CDCl ₃ , 500Hz): δ7.30-7.33 (m, 2H), 7.27-7.21 (m, 3H), 5.10-5.05 (m, 1H), 4.12-4.00 (m, 1H), 1.43 (d , 3H), 1.28-1.17 (m, 6H);

[0091]

³¹ PNMR- (CDCl ₃ , 300 Hz, H ₃ PO ₄ internal standard): δ2.04 / 2.19.

[0092]

(5) the nucleophilic reagent is KCN, the phase transfer catalyst is TBAB

[0093]

The compound was dissolved in methylene chloride as in formula 3-1 (20ml), was added TBAB (2.8mmol), the KCN (35mmol) in water (2.0ml) was added dropwise to the reaction solution. Dropping was completed, stirring was continued for 60 minutes, the solid was removed by filtration. The filtrate was washed with water, add MgSO ₄ dried for 24 hours. Filtered, and the filtrate was evaporated under reduced pressure to remove the solvent to give a compound as shown in Formula 3-2 (where X = CN).

[0094]

¹ HNMR (CDCl ₃ , 300 Hz): δ7.22-7.13 (m, 3H), 7.09-7.02 (m, 2H), 5.01-4.95 (m, 1H), 4.08-3.93 (m, 1H), 1.43-1.35 (m, 3H), 1.20-1.17 (m, 6H);

[0095]

³¹ PNMR (CDCl ₃ , 300 Hz, H ₃ PO ₄ internal standard): δ-2.71 / -2.93.

[0096]

Preparation Example 3 sofosbuvir implementation

[0097]

[0098]

(1) X is SCN

[0099]

Under 5 ℃, the compound (5.20g, 20.0mmol) as shown in Equation 2 in dry THF (30ml) in. T-butyl chloride was added with stirring (1.0M THF solution, 42ml, 42.0mmol). The reaction temperature was raised to 25 ℃, and the mixture was stirred for 30 minutes. After addition of lithium chloride (21.0mmol), was slowly added dropwise a compound of formula 3-2 (Preparation Example 2 28.4 mmol, obtained) and THF (30ml) mixed solution, keeping the temperature during at 5 ℃. After dropping was completed, the mixture was stirred for 15 hours. With aqueous 1N HCl (25ml) The reaction solution was quenched (HPLC assay Sp: Rp ratio of 6: 1). After further addition of toluene (100ml), temperature was raised to room temperature. The organic layer was washed with 1N HCl, water, 5% Na ₂ CO ₃ and washed with brine, dried over anhydrous magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure to a solid, was added methylene chloride (20ml), stirred for 5 minutes plus isopropyl ether, stirring was continued for 2 hours, the precipitated solid was filtered off. The solid was dissolved by heating in dichloromethane (60ml), slowly cooled to room temperature and the precipitated crystalline solid. Repeat if necessary obtain pure crystalline sofosbuvir (3.6g, yield 34%, HPLC purity measured 98.7%).

[0100]

¹ HNMR (CDCl ₃ , 300 MHz): [delta] 8.63 (s, 1H, NH), 7.46 (d, 1H, C6-H), 7.36 (t, 2H, O-aromatic), 7.18-7.24 (m, 3H, m, P-aromatic), 6.20-6.14 (d, 1H, Cl'-H), 5.70-5.68 (d, 1H, C5-H), 5.05-4.97 (m, 1H, CH- (CH ₃ ) ₂ ) , 4.57-4.41 (m, 2H, C5'-H2), 4.12-4.09 (d, 1H, C3'-H), 4.06-3.79 (m, 3H, C3'-OH, C4'-H, Ala-CH -CH ₃ ), 3.79 (s, 1H, Ala-NH), 1.44 (d, 3H, C2'-H3), 1.36-1.34 (d, 3H, Ala-CH ₃ ), 1.25-1.23 (t, 6H, CH- (CH ₃ ) ₂ );

[0101]

P ³¹ NMR (CDCl ₃ , 300 Hz, H ₃ PO ₄ internal standard): δ3.56.

[0102]

(2) X is N ₃

[0103]

Under 5 ℃, the compound (5.20g, 20.0mmol) as shown in Equation 2 in dry THF (30ml) in. T-butyl chloride was added with stirring (1.0M THF solution, 42ml, 42.0mmol). The reaction temperature was raised to 25 ℃, and the mixture was stirred for 30 minutes. Was added lithium chloride (21.0mmol), was slowly added dropwise after the compound of formula 3-2 obtained in Preparation Example 2 (about 28.4 mmol) and THF (30ml) mixed solution, keeping the temperature during at 5 ℃. Bi drops, stirred for 15 hours. With aqueous 1N HCl (25ml) The reaction solution was quenched (HPLC assay Sp: Rp ratio of 7: 1). After further addition of toluene (100ml), temperature was raised to room temperature. The organic layer was washed with 1N HCl, water, 5% Na ₂ CO ₃ and washed with brine, dried over anhydrous magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure to a solid, was added methylene chloride (20ml), stirred for 5 minutes plus isopropyl ether, stirring was continued for 2 hours, the precipitated solid was filtered off. The solid was dissolved by heating in dichloromethane (60ml), slowly cooled to room temperature and the precipitated crystalline solid. Repeat if necessary obtain pure crystalline sofosbuvir (4.2g, yield 40%, HPLC purity measured 98.8%).

[0104]

¹ HNMR (CDCl ₃ , 300 MHz): [delta] 8.63 (s, 1H, NH), 7.46 (d, 1H, C6-H), 7.36 (t, 2H, O-aromatic), 7.18-7.24 (m, 3H, m, P-aromatic), 6.20-6.14 (d, 1H, Cl'-H), 5.70-5.68 (d, 1H, C5-H), 5.05-4.97 (m, 1H, CH- (CH ₃ ) ₂ ) , 4.57-4.41 (m, 2H, C5'-H2), 4.12-4.09 (d, 1H, C3'-H), 4.06-3.79 (m, 3H, C3'-OH, C4'-H, Ala-CH -CH ₃ ), 3.79 (s, 1H, Ala-NH), 1.44 (d, 3H, C2'-H3), 1.36-1.34 (d, 3H, Ala-CH ₃ ), 1.25-1.23 (t, 6H, CH- (CH ₃ ) ₂ );

[0105]

P ³¹ NMR (CDCl ₃ , 300 Hz, H ₃ PO ₄ internal standard): δ3.56.

[0106]

(3) X is CN

[0107]

Under 5 ℃, the compound (5.20g, 20.0mmol) as shown in Equation 2 in dry THF (30ml) in. T-butyl chloride was added with stirring (1.0M THF solution, 42ml, 42.0mmol). The reaction temperature was raised to 25 ℃, and the mixture was stirred for 30 minutes. After addition of lithium chloride (21.0mmol), was slowly added dropwise a compound of formula 3-2 obtained in Preparation Example 2 (about 28.4 mmol) and THF (30ml) mixed solution, keeping the temperature during at 5 ℃. Bi drops, stirred for 15 hours. With aqueous 1N HCl (25ml) The reaction solution was quenched (HPLC assay Sp: Rp ratio of 6: 1). After further addition of toluene (100ml), temperature was raised to room temperature. The organic layer was washed with 1N HCl, water, 5% Na ₂ CO ₃ and washed with brine, dried over anhydrous magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure to a solid, was added methylene chloride (20ml), stirred for 5 minutes plus isopropyl ether, stirring was continued for 2 hours, the precipitated solid was filtered off. The solid was dissolved by heating in dichloromethane (60ml), slowly cooled to room temperature and the precipitated crystalline solid. Repeat if necessary obtain pure crystalline sofosbuvir (4.02g, yield 40%, HPLC purity measured 98.8%).

[0108]

¹ HNMR (CDCl ₃ , 300 MHz): [delta] 8.63 (s, 1H, NH), 7.46 (d, 1H, C6-H), 7.36 (t, 2H, O-aromatic), 7.18-7.24 (m, 3H, m, P-aromatic), 6.20-6.14 (d, 1H, Cl'-H), 5.70-5.68 (d, 1H, C5-H), 5.05-4.97 (m, 1H, CH- (CH ₃ ) ₂ ) , 4.57-4.41 (m, 2H, C5'-H2), 4.12-4.09 (d, 1H, C3'-H), 4.06-3.79 (m, 3H, C3'-OH, C4'-H, Ala-CH -CH ₃ ), 3.79 (s, 1H, Ala-NH), 1.44 (d, 3H, C2'-H3), 1.36-1.34 (d, 3H, Ala-CH ₃ ), 1.25-1.23 (t, 6H, CH- (CH ₃ ) ₂ );

[0109]

P ³¹ NMR (CDCl ₃ , 300 Hz, H ₃ PO ₄ internal standard): δ3.56.

 

 
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