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DR ANTHONY MELVIN CRASTO, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his Ph.D from ICT, 1991,Matunga, Mumbai, India, in Organic Chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with GLENMARK PHARMACEUTICALS LTD, Research Centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Total Industry exp 30 plus yrs, Prior to joining Glenmark, he has worked with major multinationals like Hoechst Marion Roussel, now Sanofi, Searle India Ltd, now RPG lifesciences, etc. He has worked with notable scientists like Dr K Nagarajan, Dr Ralph Stapel, Prof S Seshadri, Dr T.V. Radhakrishnan and Dr B. K. Kulkarni, etc, He did custom synthesis for major multinationals in his career like BASF, Novartis, Sanofi, etc., He has worked in Discovery, Natural products, Bulk drugs, Generics, Intermediates, Fine chemicals, Neutraceuticals, GMP, Scaleups, etc, he is now helping millions, has 9 million plus hits on Google on all Organic chemistry websites. His friends call him Open superstar worlddrugtracker. His New Drug Approvals, Green Chemistry International, All about drugs, Eurekamoments, Organic spectroscopy international, etc in organic chemistry are some most read blogs He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 30 year tenure till date Dec 2017, Around 35 plus products in his career. He has good knowledge of IPM, GMP, Regulatory aspects, he has several International patents published worldwide . He has good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, Polymorphism etc., He suffered a paralytic stroke/ Acute Transverse mylitis in Dec 2007 and is 90 %Paralysed, He is bound to a wheelchair, this seems to have injected feul in him to help chemists all around the world, he is more active than before and is pushing boundaries, He has 9 million plus hits on Google, 2.5 lakh plus connections on all networking sites, 50 Lakh plus views on dozen plus blogs, He makes himself available to all, contact him on +91 9323115463, email, Twitter, @amcrasto , He lives and will die for his family, 90% paralysis cannot kill his soul., Notably he has 19 lakh plus views on New Drug Approvals Blog in 216 countries...... , He appreciates the help he gets from one and all, Friends, Family, Glenmark, Readers, Wellwishers, Doctors, Drug authorities, His Contacts, Physiotherapist, etc

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Remdesivir, レムデシビル , ремдесивир , ريمديسيفير , 瑞德西韦 ,

Remdesivir (USAN.png

GS-5734 structure.png

ChemSpider 2D Image | remdesivir | C27H35N6O8P


Mol weight


ремдесивир [Russian] [INN]
ريمديسيفير [Arabic] [INN]
瑞德西韦 [Chinese] [INN]
2-Ethylbutyl (2S)-2-{[(S)-{[(2R,3S,4R,5R)-5-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydro-2-furanyl]methoxy}(phenoxy)phosphoryl]amino}propanoate (non-preferred name)

L-Alanine, N-((S)-hydroxyphenoxyphosphinyl)-, 2-ethylbutyl ester, 6-ester with 2-C-(4-aminopyrrolo(2,1-f)(1,2,4)triazin-7-yl)-2,5-anhydro-D-altrononitrile

2-Ethylbutyl (2S)-2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo(2,1-f)(1,2,4)triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate

  • 2-Ethylbutyl (2S)-2-[[(S)-[[(2R,3S,4R,5R)-5-(4-aminopyrrolo(2,1-f)(1,2,4)triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl]methoxy]phenoxyphosphoryl]amino]propanoate
  • 2-Ethylbutyl (2S)-2-[[[[(2R,3S,4R,5R)-5-(4-aminopyrrolo(2,1-f)(1,2,4)triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl]methoxy]phenoxyphosphoryl]amino]propanoate
  • 2-Ethylbutyl N-[(S)-[2-C-(4-aminopyrrolo(2,1-f)(1,2,4)triazin-7-yl)-2,5-anhydro-D-altrononitril-6-O-yl]phenoxyphosphoryl]-L-alaninate
  • GS 5734
  • L-Alanine, N-[(S)-hydroxyphenoxyphosphinyl)-, 2-ethylbutyl ester,6-ester with 2-C-(4-aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-2,5-anhydro-D-altrononitrile

Treatment of viral infections

Phase III, clinical trials for the treatment of hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (COVID-19). National Institute of Allergy and Infectious Diseases (NIAID) is evaluating remdesivir in phase II/III clinical trials for the treatment of Ebola virus infection.

The compound has been evaluated in preclinical studies for the potential treatment of Middle East respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus (SARS-CoV) infections.

Remdesivir is a nucleoside analogue, with effective antiviral activity, with EC50s of 74 nM for ARS-CoV and MERS-CoV in HAE cells, and 30 nM for murine hepatitis virus in delayed brain tumor cells.

Remdesivir (development code GS-5734) is a novel antiviral drug in the class of nucleotide analogs. It was developed by Gilead Sciences as a treatment for Ebola virus disease and Marburg virus infections,[1] though it has subsequently also been found to show antiviral activity against other single stranded RNA viruses such as respiratory syncytial virusJunin virusLassa fever virusNipah virus, Hendra virus, and the coronaviruses (including MERS and SARS viruses).[2][3] It is being studied for SARS-CoV-2 and Nipah and Hendra virus infections.[4][5][6] Based on success against other coronavirus infections, Gilead provided remdesivir to physicians who treated an American patient in Snohomish County, Washington in 2020, infected with SARS-CoV-2[7] and is providing the compound to China to conduct a pair of trials in infected individuals with and without severe symptoms.[8]

Research usage

Laboratory tests suggest remdesivir is effective against a wide range of viruses, including SARS-CoV and MERS-CoV. The medication was pushed to treat the West African Ebola virus epidemic of 2013–2016. Although the drug turned out to be safe, it was not particularly effective against filoviruses such as the Ebola virus.

Ebola virus

Remdesivir was rapidly pushed through clinical trials due to the West African Ebola virus epidemic of 2013–2016, eventually being used in at least one human patient despite its early development stage at the time. Preliminary results were promising and it was used in the emergency setting during the Kivu Ebola epidemic that started in 2018 along with further clinical trials, until August 2019, when Congolese health officials announced that it was significantly less effective than monoclonal antibody treatments such as mAb114 and REGN-EB3. The trials, however, established its safety profile.[9][10][11][12][13][14][15][16]


In response to the 2019–20 coronavirus outbreak induced by coronavirus SARS-CoV-2, Gilead provided remdesivir for a “small number of patients” in collaboration with Chinese medical authorities for studying its effects.[17]

Gilead also started laboratory testing of remdesivir against SARS-CoV-2. Gilead stated that remdesivir was “shown to be active” against SARS and MERS in animals.[3][18]

In late January 2020, remdesivir was administered to the first US patient to be confirmed to be infected by SARS-CoV-2, in Snohomish County, Washington, for “compassionate use” after he progressed to pneumonia. While no broad conclusions were made based on the single treatment, the patient’s condition improved dramatically the next day,[7] and he was eventually discharged.[19]

Also in late January 2020, Chinese medical researchers stated to the media that in exploratory research considering a selection of 30 drug candidates. Remdesivir and two other drugs, chloroquine and lopinavir/ritonavir, seemed to have “fairly good inhibitory effects” on SARS-CoV-2 at the cellular level. Requests to start clinical testing were submitted,[20][21]. On February 6, 2020, a clinical trial of remdesivir began in China.[22]

Other viruses

The active form of remdesivir, GS-441524, shows promise for treating feline coronavirus.[23]

Mechanism of action and resistance

Remdesivir is a prodrug that metabolizes into its active form GS-441524. GS-441524 is an adenosine nucleotide analog that confuses viral RNA polymerase and evades proofreading by viral exoribonuclease (ExoN), causing a decrease in viral RNA production. It was unknown whether it terminates RNA chains or causes mutations in them.[24]However, it has been learned that the RNA dependent RNA polymerase of ebolavirus is inhibited for the most part by delayed chain termination.[25]

Mutations in the mouse hepatitis virus RNA replicase that cause partial resistance were identified in 2018. These mutations make the viruses less effective in nature, and the researchers believe they will likely not persist where the drug is not being used.[24]




Remdesivir can be synthesized in multiple steps from ribose derivatives. The figure below is one of the synthesis route of remdesivir invented by Chun et al. from Gilead Sciences.[26]In this method, intermediate a is firstly prepared from L-alanine and phenyl phosphorodichloridate in presence of triethylamine and dichloromethane; triple benzyl-protected ribose is oxidized by dimethyl sulfoxide with acetic anhydride and give the lactone intermediate b; pyrrolo[2,1-f][1,2,4]triazin-4-amine is brominated, and the amine group is protected by excess trimethylsilyl chloriden-Butyllithium undergoes a halogen-lithium exchange reaction with the bromide at -78 °C to yield the intermediate c. The intermediate b is then added to a solution containing intermediate c dropwise. After quenching the reaction in a weakly acidic aqueous solution, a mixture of 1: 1 anomers was obtained. It was then reacted with an excess of trimethylsilyl cyanide in dichloromethane at -78 °C for 10 minutes. Trimethylsilyl triflate was added and reacts for an additional 1 hour, and the mixture was quenched in an aqueous sodium hydrogen carbonate. A nitrile intermediate was obtained. The protective group, benzyl, was then removed with boron trichloride in dichloromethane at -20 °C. The excess of boron trichloride was quenched in a mixture of potassium carbonate and methanol. A benzyl-free intermediate was obtained. The isomers were then separated via reversed-phase HPLC. The optically pure compound and intermediate a are reacted with trimethyl phosphate and methylimidazole to obtain a diastereomer mixture of remdesivir. In the end, optically pure remdesivir can be obtained through methods such as chiral resolution.

The synthesis of Remdesivir was invented by Byoung Kwon Chun et al. from Gilead Sciences, Inc. and claimed in the patent, WO2016069826A1.
中文: 瑞德西韋的合成方法是由吉利德科學公司的 Byoung Kwon Chun等人所發明,並在WO2016069826A1中聲明專利。

Synthesis of Remdesivir


WO 2018204198;jsessionid=E7724EB6CA3959303E18B3D392E0219F.wapp1nA?docId=WO2018204198&tab=PCTDESCRIPTION

Prevention and treatment methods for some Arenaviridae , Coronaviridae , Filoviridae, Flaviviridae, and Paramyxoviridae viruses present challenges due to a lack of vaccine or post-exposure treatment modality for preventing or managing these infections. In some cases, patients only receive supportive and resource intensive therapy such as electrolyte and fluid balancing, oxygen, blood pressure maintenance, or treatment for secondary infections. Thus, there is a need for antiviral therapies having a potential for broad antiviral activity.

[0004] The compound (S)-2-ethylbutyl 2-(((S)-(((2R,3 S,4R,5R)-5-(4-aminopyrrolo[2, 1-f][l,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy) phosphoryl)amino)propanoate, referred herein as Compound 1 or Formula I, is known to exhibit antiviral properties against Arenaviridae, Coronaviridae, Filoviridae, and

Paramyxoviridae viruses as described in Warren, T. et al., Nature (2016) 531 :381-385 and antiviral activities against Flaviviridae viruses as described in co-pending United States provisional patent application no. 62/325,419 filed April 20, 2016.

[0005] (S)-2-Ethylbutyl 2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2, l-f][l,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)

propanoate or 2-ethylbutyl ((S)-(((2R,3 S,4R,5R)-5-(4-aminopyrrolo[2, l-f][l,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)-L-alaninate, (Formula I), has the following structure:

Formula I


WO 2017184668

A. Preparation of Compounds

Example 1. (2S)-ethyl 2-(chloro(phenoxy)phosphorylamino)pro anoate (Chloridate A)

Figure imgf000086_0001

[0246] Ethyl alanine ester hydrochloride salt (1.69 g, 11 mmol) was dissolved in anhydrous CH2CI2 (10 mL) and the mixture stirred with cooling to 0 °C under N2(g). Phenyl dichlorophosphate (1.49 mL, 10 mmol) was added followed by dropwise addition of Et3N over 10 min. The reaction mixture was then slowly warmed to RT and stirred for 12 h. Anhydrous Et20 (50 mL) was added and the mixture stirred for 30 min. The solid that formed was removed by filtration, and the filtrate concentrated under reduced pressure. The residue was subjected to silica gel chromatography eluting with 0-50% EtOAc in hexanes to provide intermediate A (1.13 g, 39%). H NMR (300 MHz, CDC13) δ 7.39-7.27 (m, 5H), 4.27 (m, 3H), 1.52 (m, 3H), 1.32 (m, 3H). 31P NMR (121.4 MHz, CDC13) δ 8.2, 7.8.

Example 2. (2S)-2-ethylbutyl 2-(chloro(phenoxy)phosphorylamino)propanoate

(Chloridate B

Figure imgf000087_0001

[0247] The 2-ethylbutyl alanine chlorophosphoramidate ester B was prepared using the same procedure as chloridate A except substituting 2-ethylbutyl alanine ester for ethyl alanine ester. The material is used crude in the next reaction. Treatment with methanol or ethanol forms the displaced product with the requisite LCMS signal.

Example 3. (2S)-isopropyl 2-(chloro(phenoxy)phosphorylamino)propanoate

(Chloridate C)

Figure imgf000087_0002


[0248] The isopropyl alanine chlorophosphoramidate ester C was prepared using the same procedure as chloridate A except substituting isopropyl alanine ester for the ethyl alanine ester. The material is used crude in the next reaction. Treatment with methanol or ethanol forms the displaced product with the requisite LCMS signal.

Example 4. (2S)-2-ethylbutyl 2-((((2R,3S,4R,5R)-5-(4-aminopyrrolo[l,2-firi,2,41triazin- 7-yl)-5-cvano-3,4-dihvdroxytetrahydrofuran-2- yl)methoxy)(phenoxy)phosphorylamino)propanoate (Compound 9)

[0249] Compound 9 can be prepared by several methods described below. Procedure 1

Figure imgf000088_0001

[0250] Prepared from Compound 1 and chloridate B according to the same method as for the preparation of compound 8 as described in PCT Publication no. WO 2012/012776. 1H NMR (300 MHz, CD3OD) δ 7.87 (m, 1H), 7.31-7.16 (m, 5H), 6.92-6.89 (m, 2H), 4.78 (m, 1H), 4.50-3.80 (m, 7H), 1.45-1.24 (m, 8H), 0.95-0.84 (m, 6H). 31P NMR (121.4 MHz, CD3OD) δ 3.7. LCMS m/z 603.1 [M+H], 601.0 [M-H].

Procedure 2

Figure imgf000088_0002


[0251] (2S)-2-ethylbutyl 2-(((((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,l-f][l,2,4]triazin-7- yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino) propanoate. (2S)-2-ethylbutyl 2-(((4-nitrophenoxy)(phenoxy)phosphoryl)amino)propanoate (1.08 g, 2.4 mmol) was dissolved in anhydrous DMF (9 mL) and stirred under a nitrogen atmosphere at RT. (2R,3R,4S,5R)-2-(4-aminopyrrolo[2,l-f][l,2,4]triazin-7-yl)-3,4- dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-carbonitrile (350 mg, 1.2 mmol) was added to the reaction mixture in one portion. A solution of i-butylmagnesium chloride in THF (1M, 1.8 mL, 1.8 mmol) was then added to the reaction drop wise over 10 minutes. The reaction was stirred for 2 h, at which point the reaction mixture was diluted with ethyl acetate (50 mL) and washed with saturated aqueous sodium bicarbonate solution (3 x 15 mL) followed by saturated aqueous sodium chloride solution (15 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting oil was purified with silica gel column chromatography (0-10% MeOH in DCM) to afford (2S)-2- ethylbutyl 2-(((((2R,3S,4R,5R)-5-(4-aminopyrrolo[2, l-f][l,2,4]triazin-7-yl)-5-cyano-3,4- dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino) propanoate (311 mg, 43%, 1 :0.4 diastereomeric mixture at phosphorus) as a white solid. H NMR (400 MHz, CD3OD) δ 7.85 (m, 1H), 7.34 – 7.23 (m, 2H), 7.21 – 7.09 (m, 3H), 6.94 – 6.84 (m, 2H), 4.78 (d, / = 5.4 Hz, 1H), 4.46 – 4.33 (m, 2H), 4.33 – 4.24 (m, 1H), 4.18 (m, 1H), 4.05 – 3.80 (m, 3H), 1.52 – 1.39 (m, 1H), 1.38 – 1.20 (m, 7H), 0.85 (m, 6H). 31P NMR (162 MHz, CD3OD) δ 3.71, 3.65. LCMS m/z 603.1 [M+H], 600.9 [M-H]. HPLC (2-98% MeCN-H20 gradient with 0.1% TFA modifier over 8.5 min, 1.5mL/min, Column: Phenomenex Kinetex C18, 2.6 um 100 A, 4.6 x 100 mm ) tR = 5.544 min, 5.601 min

Separation of the (S) and (R) Diastereomers

[0252] (2S)-2-ethylbutyl 2-(((((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,l-f][l,2,4]triazin-7-yl)- 5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino) propanoate was dissolved in acetonitrile. The resulting solution was loaded onto Lux Cellulose-2 chiral column, equilibrated in acetonitrile, and eluted with isocratic

acetonitrile/methanol (95 :5 vol/vol). The first eluting diastereomer had a retention time of 17.4 min, and the second eluting diastereomer had a retention time of 25.0 min.

[0253] First Eluting Diastereomer is (S)-2-ethylbutyl 2-(((R)-(((2R,3S,4R,5R)-5-(4- aminopyrrolo[2, 1 -f] [ 1 ,2,4]triazin-7-yl)-5-cyano-3 ,4-dihydroxytetrahydrofuran-2- yl)methoxy)(phenoxy)phos horyl)amino)propanoate:

Figure imgf000089_0001

!HNMR (400 MHz, CD3OD) δ 8.05 (s, 1H), 7.36 (d, / = 4.8 Hz, 1H), 7.29 (br t, J = 7.8 Hz, 2H), 7.19 – 7.13 (m, 3H), 7.11 (d, / = 4.8 Hz, 1H), 4.73 (d, / = 5.2 Hz, 1H), 4.48 – 4.38 (m, 2H), 4.37 – 4.28 (m, 1H), 4.17 (t, / = 5.6 Hz, 1H), 4.08 – 3.94 (m, 2H), 3.94 – 3.80 (m, 1H), 1.48 (sep, / = 12.0, 6.1 Hz, 1H), 1.34 (p, / = 7.3 Hz, 4H), 1.29 (d, / = 7.2 Hz, 3H), 0.87 (t, / = 7.4 Hz, 6H). 31PNMR (162 MHz, CD3OD) δ 3.71 (s). HPLC (2-98% MeCN-H20 gradient with 0.1 % TFA modifier over 8.5 min, 1.5mL/min, Column: Phenomenex Kinetex C18, 2.6 um 100 A, 4.6 x 100 mm ) is = 5.585 min. [0254] Second Eluting Diastereomer is (S)-2-ethylbutyl 2-(((S)-(((2R,3S,4R,5R)-5-(4- aminopyrrolo[2, 1 -f] [ 1 ,2,4]triazin-7-yl)-5-cyano-3 ,4-dihydroxytetrahydrofuran-2- yl)methoxy)(phenoxy)phosphoryl)amino)propanoate:

Figure imgf000090_0001

HNMR (400 MHz, CD3OD) δ 8.08 (s, 1H), 7.36 – 7.28 (m, 3H), 7.23 – 7.14 (m, 3H), 7.08 (d, 7 = 4.8 Hz, 1H), 4.71 (d, 7 = 5.3 Hz, 1H), 4.45 – 4.34 (m, 2H), 4.32 – 4.24 (m, 1H), 4.14 (t, / = 5.8 Hz, 1H), 4.08 – 3.94 (m, 2H), 3.93 – 3.85 (m, 1H), 1.47 (sep, / = 6.2 Hz, 1H), 1.38 – 1.26 (m, 7H), 0.87 (t, / = 7.5 Hz, 6H). 31PNMR (162 MHz, CD3OD) δ 3.73 (s). HPLC (2- 98% MeCN-H20 gradient with 0.1% TFA modifier over 8.5 min, 1.5mL/min, Column: Phenomenex Kinetex C18, 2.6 urn 100 A, 4.6 x 100 mm ) tR = 5.629 min.

Example 5. (S)-2-ethylbutyl 2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolor2J- f|[l,2,41triazin-7-yl)-5-cvano-3,4-dihvdroxytetrahvdrofuran-2- yl)methoxy)(phenoxy)phosphoryl)amino)propanoate (32)

Figure imgf000090_0002

[0255] The preparation of (S)-2-ethylbutyl 2-(((S)-(((2R,3S,4R,5R)-5-(4-aminopyrrolo[2,l f][l,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2- yl)methoxy)(phenoxy)phosphoryl)amino)propanoate is described below.

Preparation of (3R,4R,5R)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)dihydrofuran-2(3H)- one.

Figure imgf000090_0003

[0256] (3R,4R,5R)-3,4-bis(benzyloxy)-5-((benzyloxy)methyl)tetrahydrofuran-2-ol (15.0g) was combined with MTBE (60.0 mL), KBr (424.5 mg), aqueous K2HP04solution (2.5M, 14.3 mL), and TEMPO (56 mg). This mixture was cooled to about 1 °C. Aqueous bleach solution (7.9%wt.) was slowly charged in portions until complete consumption of starting material as indicated through a starch/iodide test. The layers were separated, and the aqueous layer was extracted with MTBE. The combined organic phase was dried over MgS04 and concentrated under reduced pressure to yield the product as a solid.

Preparation (4-amino-7-iodopyrrolor2,l-fl ri,2,41triazine)

Figure imgf000091_0001

[0257] To a cold solution of 4-aminopyrrolo[2, l-f][l,2,4]-triazine (10.03 g; 74.8 mmol) in N,N-dimethylformamide (70.27 g), N-iodosuccinimide (17.01g; 75.6 mmol) was charged in portions, while keeping the contents at about 0 °C. Upon reaction completion (about 3 h at about 0 °C), the reaction mixture was transferred into a 1 M sodium hydroxide aqueous solution (11 g NaOH and 276 mL water) while keeping the contents at about 20-30 °C. The resulting slurry was agitated at about 22 °C for 1.5 h and then filtered. The solids are rinsed with water (50 mL) and dried at about 50 °C under vacuum to yield 4-amino-7- iodopyrrolo[2,l-f] [l,2,4]triazine as a solid. !H NMR (400 MHz, DMSO-d6) δ 7.90 (s, 1H), 7.78 (br s, 2H), 6.98 (d, J = 4.4 Hz, 1H), 6.82 (d, J = 4.4 Hz, 1H). 13C NMR (101 MHz, DMSO-d6) δ 155.7, 149.1, 118.8, 118.1, 104.4, 71.9. MS m/z = 260.97 [M+H].

Preparation (3R,4R,5R)-2-(4-aminopyrrolor2, l-firi,2,41triazin-7-yl)-3,4-bis(benzyloxy)-5- ((benzyloxy)methyl)tetrahvdrofuran-2-ol via (4-amino-7-iodopyrrolor2,l-fl ri,2,41triazine)

Figure imgf000091_0002

[0258] To a reactor under a nitrogen atmosphere was charged iodobase 2 (81 g) and THF (1.6 LV). The resulting solution was cooled to about 5 °C, and TMSC1 (68 g) was charged. PhMgCl (345mL, 1.8 M in THF) was then charged slowly while maintaining an internal temperature at about < 5°C. The reaction mixture was stirred at about 0°C for 30 min, and then cooled to about -15 °C. zPrMgCl-LiCl (311 mL, 1.1 M in THF) was charged slowly while maintaining an internal temperature below about -12 °C. After about 10 minutes of stirring at about -15 °C, the reaction mixture was cooled to about -20 °C, and a solution of lactone 1 (130 g) in THF (400 mL) was charged. The reaction mixture was then agitated at about -20 °C for about 1 h and quenched with AcOH (57 mL). The reaction mixture was warmed to about 0 °C and adjusted to pH 7-8 with aqueous NaHCC>3 (5 wt%, 1300 mL). The reaction mixture was then diluted with EtOAc (1300 mL), and the organic and aqueous layers were separated. The organic layer was washed with IN HC1 (1300 mL), aqueous NaHCC>3 (5 wt%, 1300 mL), and brine (1300 mL), and then dried over anhydrous Na2S04 and concentrated to dryness. Purification by silica gel column chromatography using a gradient consisting of a mixture of MeOH and EtOAc afforded the product.

Preparation ((2S)-2-ethylbutyl 2- (((perfluorophenoxy)(phenoxy)phosphoryl)amino)propanoate) (mixture of Sp and Rp):

1 ) phenyl dichlorophosphate

CH2CI2, -78 °C to ambient

2) pentafluorophenol

Et3N, 0 °C to ambient

Figure imgf000092_0001

[0259] L- Alanine 2-ethylbutyl ester hydrochloride (5.0 g, 23.84 mmol) was combined with methylene chloride (40 mL), cooled to about -78 °C, and phenyl dichlorophosphate (3.65 mL, 23.84 mmol) was added. Triethylamine (6.6 mL, 47.68 mmol) was added over about 60 min at about -78 °C and the resulting mixture was stirred at ambient temperature for 3h. The reaction mixture was cooled to about 0 °C and pentafluorophenol (4.4 g, 23.84 mmol) was added. Triethylamine (3.3 mL, 23.84 mmol) was added over about 60 min. The mixture was stirred for about 3h at ambient temperature and concentrated under reduced pressure. The residue was dissolved in EtOAc, washed with an aqueous sodium carbonate solution several times, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography using a gradient of EtOAc and hexanes (0 to 30%). Product containing fractions were concentrated under reduced pressure to give (2S)-2-ethylbutyl 2-(((perfluorophenoxy)(phenoxy)phosphoryl)amino)propanoate as a solid. H NMR (400 MHz, Chloroform-d) δ 7.41 – 7.32 (m, 4H), 7.30 – 7.17 (m, 6H), 4.24 – 4.16 (m, 1H), 4.13 – 4.03 (m, 4H), 4.01 – 3.89 (m, 1H), 1.59 – 1.42 (m, 8H), 1.40 – 1.31 (m, 8H), 0.88 (t, J = 7.5 Hz, 12H). 31P NMR (162 MHz, Chloroform-d) δ – 1.52. 19F NMR (377 MHz, Chloroform-d) δ – 153.63, – 153.93 (m), – 160.05 (td, J = 21.9, 3.6 Hz), – 162.65 (qd, J = 22.4, 20.5, 4.5 Hz). MS m/z = 496 [M+H]. Preparation of Title Compound (mixture of Sp and Rp):

Figure imgf000093_0001

[0260] The nucleoside (29 mg, 0.1 mmol) and the phosphonamide (60 mg, 0.12 mmol) and N,N-dimethylformamide (2 mL) were combined at ambient temperature. 7¾ri-Butyl magnesiumchloride (1M in THF, 0.15 mL) was slowly added. After about lh, the reaction was diluted with ethyl acetate, washed with aqueous citric acid solution (5%wt.), aqueous saturated NaHC03 solution and saturated brine solution. The organic phase was dried over Na2S04 and concentrated under reduced pressure. The residue was purified by silica gel column chromatography using a gradient of methanol and CH2CI2 (0 to 5%). Product containing fractions were concentrated under reduced pressure to provide the product.

Preparation of (3aR,4R,6R,6aR)-4-(4-aminopyrrolor2, l-firi,2,41triazin-7-yl)-6- (hvdroxymethyl)-2,2-dimethyltetrahydrofuror3,4-diri,31dioxole-4-carbonitrile:

Figure imgf000093_0002

[0261] To a mixture of (2R,3R,4S,5R)-2-(4-aminopyrrolo[2, l-f] [l,2,4]triazin-7-yl)-3,4- dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-carbonitrile (5.8g, 0.02 mol), 2,2- dimethoxypropane (11.59 mL, 0.09 mol) and acetone (145 mL) at ambient temperature was added sulfuric acid (18M, 1.44 mL). The mixture was warmed to about 45 °C. After about 30 min, the mixture was cooled to ambient temperature and sodium bicarbonate (5.8 g) and water 5.8 mL) were added. After 15 min, the mixture was concentrated under reduced pressure. The residue was taken up in ethyl acetate (150 mL) and water (50 mL). The aqueous layer was extracted with ethyl acetate (2 x 50 mL). The combined organic phase was dried over sodium sulfate and concentrated under reduced pressure to give crude (2R,3R,4S,5R)-2-(4-aminopyrrolo[2, l-f] [l,2,4]triazin-7-yl)-3,4-dihydroxy-5- (hydroxymethyl)tetrahydrofuran-2-carbonitrile. !H NMR (400 MHz, CD3OD) δ 7.84 (s, 1H), 6.93 (d, / = 4.6 Hz, 1H), 6.89 (d, / = 4.6 Hz, 1H), 5.40 (d, / = 6.7 Hz, 1H), 5.00 (dd, / = 6.7, 3.3 Hz, 1H), 4.48 – 4.40 (m, 1H), 3.81 – 3.72 (m, 2H), 1.71 (s, 3H), 1.40 (s, 3H). MS m/z = 332.23 [M+l].

Preparation of (2S)-2-ethylbutyl 2-(((((2R,3S,4R,5R)-5-(4-aminopyrrolor2,l-firi,2,41triazin- 7-yl)-5-cvano-3,4-dihvdroxytetrahydrofuran-2- yl)methoxy)(phenoxy)phosphoryl)amino)propanoate:

Figure imgf000094_0001

[0262] Acetonitrile (100 mL) was combined with (2S)-2-ethylbutyl 2-(((4- nitrophenoxy)(phenoxy)phosphoryl)-amino)propanoate (9.6 g, 21.31 mmol), the substrate alcohol (6.6 g, 0.02 mol), magnesium chloride (1.9 g, 19.91 mmol) at ambient temperature. The mixture was agitated for about 15 min and N,N-diisopropylethylamine (8.67 mL, 49.78 mmol) was added. After about 4h, the reaction was diluted with ethyl acetate (100 mL), cooled to about 0 °C and combined with aqueous citric acid solution (5%wt., 100 mL). The organic phase was washed with aqueous citric acid solution (5%wt., 100 mL) and aqueous saturated ammonium chloride solution (40 mL), aqueous potassium carbonate solution

(10%wt., 2 x 100 mL), and aqueous saturated brine solution (100 mL). The organic phase was dried with sodium sulfate and concentrated under reduced pressure to provide crude product. !H NMR (400 MHz, CD3OD) δ 7.86 (s, 1H), 7.31 – 7.22 (m, 2H), 7.17 – 7.09 (m, 3H), 6.93 – 6.84 (m, 2H), 5.34 (d, / = 6.7 Hz, 1H), 4.98 (dd, / = 6.6, 3.5 Hz, 1H), 4.59 – 4.50 (m, 1H), 4.36 – 4.22 (m, 2H), 4.02 (dd, / = 10.9, 5.7 Hz, 1H), 3.91 (dd, / = 10.9, 5.7 Hz, 1H), 3.83 (dq, / = 9.7, 7.1 Hz, 1H), 1.70 (s, 3H), 1.50 – 1.41 (m, 1H), 1.39 (s, 3H), 1.36 – 1.21 (m, 7H), 0.86 (t, / = 7.4 Hz, 6H). MS m/z = 643.21 [M+l]. Preparation of (S)-2-ethylbutyl 2-(((S)-(((2R.3S.4R.5R)-5-(4-aminopyrrolor2.1- firi,2,41triazin-7-yl)-5-cvano-3,4-ditivdroxytetratiydrofuran-2- yl)methoxy)( henoxy)phosphoryl)amino)propanoate (Compound 32)

Figure imgf000095_0001

Compound 32

[0263] The crude acetonide (12.85 g) was combined with tetrahydrofuran (50 mL) and concentrated under reduced pressure. The residue was taken up in tetrahydrofuran (100 mL), cooled to about 0 °C and concentrated HC1 (20 mL) was slowly added. The mixture was allowed to warm to ambient temperature. After consumption of the starting acetonide as indicated by HPLC analysis, water (100 mL) was added followed by aqueous saturated sodium bicarbonate solution (200 mL). The mixture was extracted with ethyl acetate (100 mL), the organic phase washed with aqueous saturated brine solution (50 mL), dried over sodium sulfated and concentrated under reduced pressure. The residue was purified by silica gel column chromatography using a gradient of methanol and ethyl acetate (0 to 20%).

Product containing fractions were concentrated under reduced pressure to provide the product.


US 20170071964

US 20160122374


Journal of Medicinal Chemistry (2017), 60(5), 1648-1661.

The recent Ebola virus (EBOV) outbreak in West Africa was the largest recorded in history with over 28,000 cases, resulting in >11,000 deaths including >500 healthcare workers. A focused screening and lead optimization effort identified 4b (GS-5734) with anti-EBOV EC50 = 86 nM in macrophages as the clinical candidate. Structure activity relationships established that the 1′-CN group and C-linked nucleobase were critical for optimal anti-EBOV potency and selectivity against host polymerases. A robust diastereoselective synthesis provided sufficient quantities of 4b to enable preclinical efficacy in a non-human-primate EBOV challenge model. Once-daily 10 mg/kg iv treatment on days 3–14 postinfection had a significant effect on viremia and mortality, resulting in 100% survival of infected treated animals [ Nature 2016531, 381−385]. A phase 2 study (PREVAIL IV) is currently enrolling and will evaluate the effect of 4b on viral shedding from sanctuary sites in EBOV survivors.

(S)-2-Ethylbutyl 2-(((S)-(((2R,3S,4R,5R)-5-(4-Aminopyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydrofuran-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate (4b)

Compound 4b was prepared from 4 and 22b as described previously.(17)1H NMR (400 MHz, methanol-d4): δ 7.86 (s, 1H), 7.33–7.26 (m, 2H), 7.21–7.12 (m, 3H), 6.91 (d, J = 4.6 Hz, 1H), 6.87 (d, J = 4.6 Hz, 1H), 4.79 (d, J = 5.4 Hz, 1H), 4.43–4.34 (m, 2H), 4.28 (ddd, J = 10.3, 5.9, 4.2 Hz, 1H), 4.17 (t, J = 5.6 Hz, 1H), 4.02 (dd, J = 10.9, 5.8 Hz, 1H), 3.96–3.85 (m, 2H), 1.49–1.41 (m, 1H), 1.35–1.27 (m, 8H), 0.85 (t, J = 7.4 Hz, 6H).
13C NMR (100 MHz, methanol-d4): δ 174.98, 174.92, 157.18, 152.14, 152.07, 148.27, 130.68, 126.04, 125.51, 121.33, 121.28, 117.90, 117.58, 112.29, 102.60, 84.31, 84.22, 81.26, 75.63, 71.63, 68.10, 67.17, 67.12, 51.46, 41.65, 24.19, 20.56, 20.50, 11.33, 11.28.
 31P NMR (162 MHz, methanol-d4): δ 3.66 (s).
HRMS (m/z): [M]+ calcd for C27H35N6O8P, 602.2254; found, 602.2274.
[α]21D – 21 (c 1.0, MeOH).


Nature (London, United Kingdom) (2016), 531(7594), 381-385.

GS-5734 structure.png
Clinical data
Other names GS-5734
Routes of
By mouthinsufflation
ATC code
  • None
Legal status
Legal status
CAS Number
Chemical and physical data
Formula C27H35N6O8P
Molar mass 602.585 g·mol−1
3D model (JSmol)
GS-5734 structure.png
Clinical data
Other names GS-5734
Routes of
By mouthinsufflation
ATC code
  • None
Legal status
Legal status
CAS Number
Chemical and physical data
Formula C27H35N6O8P
Molar mass 602.585 g·mol−1
3D model (JSmol)

//////////////Remdesivir, レムデシビル , UNII:3QKI37EEHE, ремдесивир ريمديسيفير 瑞德西韦 , GS-5734 , GS 5734, PHASE 3 , CORONOVIRUS, COVID-19





CAS: 1312608-46-0
Chemical Formula: C41H50N8O8
Molecular Weight: 782.89


methyl {(2S)-1-[(2S)-2-(4-{4-[7-(2-[(2S)-1-{(2S)-2- [(methoxycarbonyl)amino]-3-methylbutanoyl}pyrrolidin-2-yl]-1H-imidazol-4-yl)-2H-1,3-benzodioxol-4-yl]phenyl}-1Himidazol-2-yl)pyrrolidin-1-yl]-3-methyl-1-oxobutan-2-yl}carbamate

Carbamic acid, N-((1S)-1-(((2S)-2-(5-(4-(7-(2-((2S)-1-((2S)-2-((methoxycarbonyl)amino)-3-methyl-1-oxobutyl)-2-pyrrolidinyl)-1H-imidazol-5-yl)-1,3-benzodioxol-4-yl)phenyl)-1H-imidazol-2-yl)-1-pyrrolidinyl)carbonyl)-2-methylpropyl)-, methyl ester

hepatitis C virus infection


Coblopasvir is an antiviral drug candidate.

Coblopasvir dihydrochloride

CAS 1966138-53-3

C41 H50 N8 O8 . 2 Cl H
 Molecular Weight 855.806
PHASE 3 Beijing Kawin Technology Share-Holding
Hepatitis C virus (HCV), or hepatitis C virus infection, is a chronic blood-borne infection. Studies have shown that 40% of chronic liver diseases are associated with HCV infection, and an estimated 8,000-10,000 people die each year. HCV-related end-stage liver disease is the most common indication for liver transplantation in adults.
In the past ten years, antiviral therapy for chronic liver disease has developed rapidly, and significant improvement has been seen in the treatment effect. However, even with the combination therapy with pegylated IFN-α plus ribavirin, 40% to 50% of patients fail to treat, that is, they are non-responders or relapsers. These patients do not currently have an effective treatment alternative. Because the risk of HCV-related chronic liver disease is related to the duration of HCV infection, and the risk of cirrhosis increases in patients who have been infected for more than 20 years, chronic liver disease often progresses to advanced stages with cirrhosis, ascites, jaundice, and rupture of varicose veins. , Brain disease, and progressive liver failure, and the risk of liver cancer is also significantly increased.
HCV is a enveloped positive-strand RNA virus of the Flaviviridae family. The single-stranded HCV RNA genome is approximately 9500 nucleotides in length and has a single open reading frame (ORF) that encodes a single open reading frame (ORF) of approximately 3,000 amino acids. Mostly polyprotein. In infected cells, cellular and viral proteases cleave this polyprotein at multiple sites to produce viral structural and non-structural (NS) proteins. There are two viral proteases that affect the production of mature non-structural proteins (NS2, NS3, NS4, NS4A, NS4B, NS5A, and NS5B). The first viral protease is cleaved at the NS2-NS3 junction of the polyprotein; the second viral protease is A “NS3 protease” that mediates all subsequent cleavage events at a site downstream of the NS3 position relative to the polyprotein (ie, the site between the C-terminus of NS3 and the C-terminus of the polyprotein). The NS3 protease exhibits cis-activity at the NS3-NS4 cleavage site and, conversely, exhibits trans-activity at the remaining NS4A-NS4B, NS4B-NS5A, and NS5A-NS5B sites. The NS4A protein is thought to provide multiple functions, such as acting as a cofactor for the NS3 protease, and may promote membrane localization of NS3 and other viral replicase components. The formation of a complex between NS3 and NS4A may be necessary for NS3-mediated processing events and improves the proteolytic efficiency at all sites recognized by NS3. NS3 protease may also exhibit nucleotide triphosphatase and RNA helicase activity. NS5B is an RNA-dependent RNA polymerase involved in HCV RNA replication. In addition, compounds that inhibit the effects of NS5A in viral replication may be useful for treating HCV.

Beijing Kawin Technology Share-Holding, in collaboration with Beijing Fu Rui Tiancheng Biotechnology and Ginkgo Pharma , is developing coblopasvir as an oral capsule formulation of dihydrochloride salt (KW-136), for treating hepatitis C virus infection. In June 2018, an NDA was filed in China by Beijing Kawin Technology and Sichuan Qingmu Pharmaceutical . In August 2018, the application was granted Priority Review in China . Also, Beijing Kawin is investigating a tablet formulation of coblopasvir dihydrochloride.


WO2011075607 , claiming substituted heterocyclic derivatives as HCV replication inhibitors useful for treating HCV infection and liver fibrosis, assigned to Beijing Kawin Technology Share-Holding Co Ltd and InterMune Inc ,


CN 108675998



Novel crystalline and amorphous forms of methyl carbamate compound, particularly coblopasvir dihydrochloride , (designated as Forms H) processes for their preparation, compositions and combinations comprising them are claimed. Also claim is an article or kit comprising a container and a package insert, wherein the container contains coblopasvir dihydrochloride.

Step 7
To a solution of compound 1-IXf (250 mg, 0.31 mmol) in toluene (10.0 mL) was added NH4OAc (4.0 g, 50 mmol) and the mixture was refluxed for 16 hours. The reaction mixture was diluted with ethyl acetate and washed with water and brine. The solvent was removed and the residue was purified by preparative HPLC to give Compound I (43.5 mg, yield 20%) as a white solid. MS (ESI) m / z (M + H) + 783.4.
Example 2 Preparation of a compound of formula II
Compound of formula (I) N-[(2S) -1-[(2S) -2- {4- [7- (4- {2-[(2S) -1-[(2S) -2-[(A Oxycarbonyl) amino] -3-methylbutanoyl] pyrrolidin-2-yl] -1H-imidazol-4-yl} phenyl) -2H-1,3-benzodioxo-4-yl] Preparation of -1H-imidazol-2-yl} pyrrolidin-1-yl] -3-methyl-1-oxobutane-2-yl] carbamate dihydrochloride
At room temperature, a solution of the pure product of structural formula I (800 g, 1.0 eq) and ethyl acetate (8 L) were sequentially added to a 20 L bottle and stirred. A 11.2% HCl / ethyl acetate solution (839 g) was added dropwise to the system, the temperature of the system was controlled at 15 ° C to 25 ° C, and the mixture was stirred for more than 3 hours to stop the reaction. The filter cake was filtered with ethyl acetate (2L). Wash the cake, bake the cake at a controlled temperature of 40-60 ° C, sample and test until the ethyl acetate residue is <0.5%, (about 73 hours of baking), to obtain the compound of formula II, off-white solid powder or granules, 774 g, HPLC Purity: 98.65%, yield: 88.5%, tested XRPD as amorphous.

///////////////Coblopasvir , KW-136, hepatitis C virus infection, CHINA, Beijing Kawin Technology, NDA, Phase III


Benvitimod, Tapinarof, тапинароф , تابيناروف , 他匹那罗 ,

Chemical structure of benvitimod

ChemSpider 2D Image | 3,5-Dihydroxy-4-isopropyl-trans-stilbene | C17H18O2

Benvitimod, Tapinarof


Launched – 2019 CHINA, Psoriasis, Tianji Pharma
 [Russian] [INN]WBI-1001

تابيناروف [Arabic] [INN]
他匹那罗 [Chinese] [INN]
1,3-Benzenediol, 2-(1-methylethyl)-5-(2-phenylethenyl)-, (E)-
1,3-Benzenediol, 2-(1-methylethyl)-5-[(E)-2-phenylethenyl]-
79338-84-4 [RN]
Research Code:WB-1001; WBI-1001
Trade Name:MOA:NSAID
Indication:Atopic dermatitis; PsoriasisStatus:
Phase III (Active)
Company:GlaxoSmithKline (Originator), Welichem Biotech (Originator), 天济药业 (Originator)
84HW7D0V04 (UNII code)
In May 2019, the drug was appoved in China for the treatment of moderate stable psoriasis vulgaris in adults and, in July 2019, Tianji Pharma (subsidiary of Guanhao Biotech) launched the product in China for the treatment of moderate stable psoriasis vulgaris in adults.

Benvitimod is in phase III clinical trials, Dermavant Sciences for the treatment of atopic dermatitis and psoriasis.

The compound was co-developed by Welichem Biotech and Stiefel Laboratories (subsidiary of GSK). However, Shenzhen Celestial Pharmaceuticals acquired the developement rights in China, Taiwan, Macao and Hong Kong.

Benvitimod (also known as Tapinarof or 3,5-dihydroxy-4-isopropyl-trans-stilbene) is a bacterial stilbenoid produced in Photorhabdus bacterial symbionts of Heterorhabditis nematodes.It is a product of an alternative ketosynthase-directed stilbenoids biosynthesis pathway. It is derived from the condensation of two β-ketoacyl thioesters. It is produced by the Photorhabdus luminescens bacterial symbiont species of the entomopathogenic nematode, Heterorhabditis megidis.

Benvitimod (also known as tapinarof or 3,5-dihydroxy-4-isopropyl-trans-stilbene) is a bacterial stilbenoid produced in Photorhabdus bacterial symbionts of Heterorhabditis nematodes. It is a product of an alternative ketosynthase-directed stilbenoids biosynthesis pathway. It is derived from the condensation of two β-ketoacyl thioesters .[1] It is produced by the Photorhabdus luminescens bacterial symbiont species of the entomopathogenic nematode, Heterorhabditis megidis. Experiments with infected larvae of Galleria mellonella, the wax moth, support the hypothesis that the compound has antibiotic properties that help minimize competition from other microorganisms and prevents the putrefaction of the nematode-infected insect cadaver.[2]

Tapinarof is a non-steroidal anti-inflammatory drug originated by Welichem Biotech. Dermavant Sciences is developing the product outside China in phase III clinical trials for the treatment of plaque psoriasis. The company is also conducting phase II clinical trials for the treatment of atopic dermatitis. Phase II studies had also been conducted by Welichem Biotech and Stiefel (subsidiary of GlaxoSmithKline) for these indications.

Tapinarof was originated at Welichem Biotech, from which Tianji Pharma and Shenzen Celestial Pharmaceuticals obtained rights to the product in the Greater China region in 2005. In 2012, Welichem licensed development and commercialization rights in all other regions to Stiefel. In 2013, Welichem entered into an asset purchase agreement to regain Greater China rights to the product from Tianji Pharma and Celestial; however, this agreement was terminated in 2014. In 2018, Stiefel transferred its product license to Dermavant Sciences.

Entomopathogenic nematodesemerging from a wax moth cadaver

Medical research

Benvitimod is being studied in clinical trials for the treatment of plaque psoriasis.[3]


Route 1

1. US2003171429A1.

2. US2005059733A1.

Route 2

Reference:1. CN103265412A.



phenalkenyl Maude (Benvitimod) is a new generation of anti-inflammatory drugs, are useful for treating a variety of major autoimmune diseases, such as psoriasis, eczema, hair and more concentrated colitis allergic diseases.Phenalkenyl Maud stilbene compound, comprising cis and trans isomers, the trans alkenyl benzene Maude has a strong physiological activity, stability and physical and chemical properties, and cis alkenyl benzene Modesto predominantly trans phenalkenyl Maud byproducts during synthesis, conventional methods such as benzene alkenyl Maude Wittig reaction of cis-isomer impurity is inevitable.

Figure CN103992212AD00041

[0004] benzyl trans-alkenyl Maude as main impurities in the synthesis, whether a drug is detected, or monitored during the reaction, the synthesis and analysis methods established cis alkenyl benzene Maude has very important significance.Phenalkenyl Maud conventional synthetic methods the impurity content is very low, and the properties of the cis compound is extremely unstable, easily converted to trans-structure, the synthetic method according to the preceding, the cis compound difficult to separate. The synthesis method has not been reported before in the literature. Thus, to find a synthesis route of cis-alkenyl benzene Maude critical.

[0005] The synthesis of compounds of cis-stilbene, in the prior art, there have been many reports, however, the prior art method of synthesizing a reaction product of the cis starting materials and reagents difficult source, the catalyst used is expensive higher costs, operational difficulties, is not conducive to large-scale production, such as:

① Gaukroger K, John A.Hadfield.Novel syntheses of cis and trans isomers ofcombretastatin A-4 [J] .J.0rg.Chemj 2001, (66): 8135-8138, instead of styrene and substituted phenyl bromide boric acid as the raw material, the Suzuki coupling reaction is a palladium catalyst, to give the cis compound, the reaction follows the formula:

Figure CN103992212AD00051

Yield and selectivity of the process the structure is good, but the reaction is difficult source of raw materials, catalyst more expensive, limiting the use of this method.

[0006] ② Felix N, Ngassaj Erick A, Lindsey, Brandon Ej Haines.The first Cu- and

amine-free Sonogashira-type cross-coupling in the C_6 -alkynylation of protected

2, -deoxyadenosine [J] .Tetrahedron Letters, 2009, (65): 4085-4091, with a substituted phenethyl m

Alkynyl easily catalyst Pd / CaC03, Fe2 (CO) 9, Pd (OAc) 2 and the like produce cis compound to catalytic reduction. The reaction follows the formula:

Figure CN103992212AD00052

Advantage of this method is stereospecific reduction of alkynes in the catalyst, to overcome the phenomenon of cis-trans isomerization of the Wittig reaction, but the reaction requires at _78 ° C, is not conducive to the operation, and the reagent sources difficult, expensive than high cost increase is not conducive to mass production.

[0007] ③ Belluci G, Chiappe C, Moro G L0.Crown ether catalyzed stereospecificsynthesis of Z_and E-stilbenes by Wittig reaction in a solid-liquid two-phasessystem [J] .Tetrahedron Letters, 1996, (37): 4225-4228 using Pd (PPh3) 4 as catalyst, an organic zinc reagent with a halide compound of cis-coupling reaction formula as follows:

Figure CN103992212AD00053

The advantage of this method is that selective, high yield to give cis; deficiency is difficult to handle, the catalyst is expensive.

[0008] ④ new Wang, Zhangxue Jing, Zhou Yue, Zouyong Shun, trans-3,4 ‘, 5-trihydroxy-stilbene China Pharmaceutical Synthesis, 2005, 14 (4);. 204-208, reported that the trans compound of formula was dissolved in DMSO solution at a concentration dubbed, ultraviolet irradiation was reacted at 365nm, converted into cis compounds, see the following reaction formula:

Figure CN103992212AD00061

However, the concentration of the solution preparation method, the reaction time is more stringent requirements.

Figure CN103992212AD00062

The synthesis of cis-alkenyl benzene Maude application embodiments Example 1 A synthesis of cis-alkenyl Maude benzene and benzene-cis-ene prepared Maude, the reaction was carried out according to the following scheme:

Figure CN103992212AD00101

Specific preparation process steps performed in the following order:

(O methylation reaction

The 195.12g (Imol) of 3, 5-hydroxy-4-isopropyl benzoic acid, 414.57g (3mol) in DMF was added 5000ml anhydrous potassium carbonate, mixing, stirred at room temperature, then cooled in an ice-salt bath next, slowly added dropwise 425.85g (3mol) of iodomethane, warmed to room temperature after the addition was complete, the reaction 2h, after completion of the reaction was stirred with water, extracted with ethyl acetate, and concentrated to give 3,5-dimethoxy-4- isopropyl benzoate; yield 93%, purity of 99%.

[0033] (2) a reduction reaction

3000ml tetrahydrofuran and 240g (Imol) 3,5-dimethoxy-4-isopropyl benzoate, 151.40g (4mol) mixing at room temperature sodium borohydride was stirred and heated to reflux was slowly added dropwise 400ml methanol, reaction 4h, was added 3L of water was stirred, extracted with ethyl acetate, washed with water, the solvent was removed by rotary evaporation to give a white solid, to give 3,5-dimethoxy-4-isopropylbenzene methanol; 96% yield purity was 99%.

[0034] (3) the oxidation reaction

The 212g (ImoI) of 3,5-dimethoxy-4-isopropylbenzene methanol, DMSO 800ml and 500ml of acetic anhydride were mixed and stirred at rt After 2h, stirred with water, extracted with ethyl acetate, washed with water, dried , and concentrated to give 3,5-dimethoxy-4-isopropyl-benzaldehyde; 94% yield, 99% purity.

[0035] (4) a condensation reaction

The mixture was 209.18g (lmol) of 3,5-dimethoxy-4-isopropyl-benzoic awake and 136.15g (Imol) phenylacetic acid was added 5000ml of acetic anhydride, stirred to dissolve, sodium acetate was added 246.09g , heating to 135 ° C, the reaction after 6h, cooled to room temperature after adjusting the dilute acid 2 was added, extracted with ethyl acetate, the pH was concentrated, added saturated sodium bicarbonate solution adjusted to pH 7, stirred 2h, and extracted with dichloromethane , adding dilute aqueous hydrochloric acid pH 2, the yellow solid was filtered, to obtain 3,5-dimethoxy-4-isopropyl-stilbene acid; 96% yield, 80% purity.

[0036] (5) decarboxylation reaction

The 327g (Imol) of 3,5-dimethoxy-4-isopropyl-stilbene acid and 384g (6mol) of copper powder were added to 5000ml of quinoline, 180 ° C reaction 3h, cooled to room temperature ethyl acetate was added with stirring, filtered, and the filtrate was washed with dilute hydrochloric acid to the aqueous layer was colorless and the aqueous phase was extracted with ethyl acetate inverted, the organic layers were combined, washed with water and saturated brine until neutral, i.e., spin-dried to give 3,5 – dimethoxy-4-isopropyl-stilbene; 92% yield, 77% purity.

[0037] (6) Demethylation

The 282.32g (Imol) of 3,5-dimethoxy-4-isopropyl-stilbene 4000ml toluene was placed in an ice bath and stirring, was cooled to 0 ° C, and dissolved slowly added 605.9g (5mol after) in N, N- dimethylaniline, was added 666.7g (5mol) of anhydrous aluminum chloride. after stirring for 0.5h, warmed to room temperature, the reaction was heated to 100 ° C 2h, cooled to 60 ° C , hot toluene layer was separated, diluted hydrochloric acid was added to the aqueous phase with stirring to adjust the PH value of 2, extracted with ethyl acetate, washed with water, and concentrated to give the cis-alkenyl benzene Modesto; crude yield 95%, purity 74 %.After separation by column chromatography using 300-400 mesh silica gel, benzene-cis-ene was isolated Maude pure, 68% yield, 98.5% purity. The resulting cis-alkenyl benzene Maud NMR shown in Figure 1, NMR data are as follows:

1HNMR (CDCl3, 500 Hz, δ: ppm), 7.255 (m, 5H), 6.558 (d, 1H), 6.402 (d, 1H), 6.218 (s, 2H), 4.872 (s, 2H), 3.423 (m , 1H), 1.359 (q, 6H). Coupling constants / = 12.

[0038] trans-alkenyl benzene Maud NMR shown in Figure 2, the following NMR data:

1HNMR (CDCl3, 500 Hz, δ: ppm), 7.477 (d, 2H), 7.360 (t, 2H), 6.969 (q, 2H), 6.501 (s, 1H), 4.722 (s, 2H), 3.486 (m , 1H), 1.380 (t, 6H). Coupling constants / = 16.

[0039] HPLC conditions a cis alkenyl benzene Maude pure product: column was Nucleosil 5 C18; column temperature was 20 ° C; detection wavelength 318nm; mobile phase consisting of 50:50 by volume of acetonitrile and water; flow rate It was 0.6mL / min, injection volume of 5 μ L; cis phenalkenyl Maude 18.423min retention time of a peak in an amount of 96.39%, see Figure 3. Trans phenalkenyl Maude 17.630min retention time of a peak, the content was 99.8%, see Figure 4.After mixing the two, trans-alkenyl benzene Maude 17.664min retention time of the peak, cis-alkenyl benzene Maude 18.458min retention time of the peak, see Figure 5.


Figure CN103172497AC00021

phenalkenyl Maude is a natural product, a metabolite as to be symbionts.Phenalkenyl Maud Escherichia coli, Staphylococcus aureus has a very significant inhibitory effect, in addition, there is a styrenic Maude suppression of inflammation and its reactive derivative with immunomodulating activity. Alkenyl benzene Modesto topical ointment as an active ingredient, as a class of drugs has been completed two clinical treatment of psoriasis and eczema, the results of ongoing clinical phase III clinical studies, it has been shown to be completed in both psoriasis and eczema clearly effect, together with a styrenic Maude is a non-hormonal natural small molecule compounds, can be prepared synthetically prepared, therefore, it exhibits good market prospect.

[0004] a styrenic Maude initial synthesis route is as follows:


Figure CN103172497AD00041

[0006] The reaction conditions for each step: 1) isopropanol, 80% sulfuric acid, 60 ° C, 65% .2) sodium borohydride, boron trifluoride, tetrahydrofuran, 0 ° C, 90% .3). of thionyl chloride, heated under reflux, 85% .4). triethyl phosphate, 120 ° C, 80% .5). benzaldehyde, sodium hydride, 85% .6) pyridine hydrochloride, 190 ° C, 60 %.

[0007] The chemical synthesis route, although ultimately obtained a styrenic Maude, but the overall yield is low, part of the reaction step is not suitable for industrial production, due to process conditions result in the synthesis of certain byproducts produced is difficult to remove impurities, difficult to achieve the quality standard APIs.

Preparation of 4-isopropyl-dimethoxy-benzoic acid [0011] 1,3,5_

[0012] 1000 l reactor 200 liters of 80% sulfuric acid formulation (V / V), the temperature was lowered to room temperature, put 80 kg 3,5_-dimethoxybenzoate ,, stirring gradually warmed to 60 ° C, in was added dropwise within 25 kg of isopropanol I hour, the reaction was complete after 5 hours, 500 liters of hot water, filtered, the filter cake was washed with a small amount of hot water I th, crushed cake was removed and dried. The dried powder was recrystallized from toluene, the product was filtered to give 78 kg `, yield 86%. Preparation 2,3,5_ dimethoxy-4-isopropylbenzene methanol

[0013] 1000 l reactor was added 50 kg 3,5_ _4_ isopropyl dimethoxy benzoic acid, 24 kg of potassium borohydride, 400 l of THF, at room temperature was slowly added dropwise 65 kg BF3.Et2O was stirred 12 hours, the reaction was complete, pure water was added dropwise to destroy excess BF3, filtered, concentrated to dryness, methanol – water to give an off-white recrystallized 40.3 kg, yield 90.1%.

[0014] Preparation of 3,3,5-_ ■ methoxy _4- isopropyl group gas section

[0015] 1000 l autoclave, 100 kg of 3,5-dimethoxy-4-isopropylbenzene methanol, 220 l of DMF, 0 ° C and added dropwise with stirring and 50 l of thionyl chloride, 24 hours after the reaction was complete, 300 liters of water and 300 liters of ethyl acetate, the aqueous phase was stirred layered discharged, and then washed with 200 liters of water was added 3 times, until complete removal of DMF, was added concentrated crystallized from petroleum ether to give 98 kg of white solid was filtered and dried a yield of 91%.

Preparation of methyl-dimethoxy-4-isopropylbenzene of diethyl [0016] 4,3,5_

[0017] 500 l autoclave, 98 kg 3,5_ _4_ isopropyl dimethoxy benzyl chloride and 120 l of triethyl phosphite, the reaction at 120 ° C 5h, fear distilled off under reduced pressure, the collection 145-155 ° C / 4mmHg fear minutes, cured at room temperature to give a colorless light solid was 118 kg, yield 81.6%.

, 3- [0018] 5, E-1 _ ■ methoxy-2-isopropyl-5- (2-phenylethyl lean-yl) – benzene

[0019] 500 l autoclave, 33 kg 3,5_-dimethoxy-4-isopropylbenzene acid diethyl ester, 10.8 kg of benzaldehyde, and 120 l of tetrahydrofuran, at 40 ° C, and nitrogen with stirring, was added dropwise a solution of 11.8 kg potassium tert-butoxide in 50 liters of tetrahydrofuran, the temperature dropping control not to exceed 50 ° C. after the dropwise addition stirring was continued for I h, the reaction was complete, 150 liters of ethyl acetate and extracted , washed twice with 150 liters of water, 100 l I washed with brine, and the organic phase was dried and concentrated, methanol – water (I: D as a white crystalline solid 25.3 kg, yield 91%.

[0020] 6> 1, 3 ~ _ ■ Light-2-isopropyl-5- (2-phenylethyl lean-yl) – benzene (I), (De Dae dilute benzene)

[0021] 100 l autoclave, 10 kg 1,3_-dimethoxy-2-isopropyl-5- (2-styryl) benzene _ pyridine hydrochloride and 25 kg nitrogen atmosphere was heated to 180 -190 ° C, stirred for 3 hours after the reaction was completed, 20 l HCl (2N) cooling to 100 ° C, and 20 liters of ethyl acetate the product was extracted, dried and concentrated to give the product 7.3 kg, 83% yield.

[0022] The method for purifying:

[0023] 100 l added to the reaction vessel 15.5 kg of crude product and 39 liters of toluene, heated to the solid all dissolved completely, filtered hot and left to crystallize, after crystallization, filtration, the crystals with cold toluene 10 washed liter at 60 ° C, protected from light vacuo dried for 24 hours, to obtain 14 kg of white needle crystals, yield 90%.


Design new synthesis of Route of Benvitimod

Nov 26, 2018
1.Benvitimod and intermediates
Benvitimod 79338-84-4  intermediate: 1999-10-5
Benvitimod 79338-84-4  intermediate: 2150-37-0
Benvitimod 79338-84-4  intermediate: 344396-17-4
Benvitimod 79338-84-4  intermediate: 344396-18-5
Benvitimod 79338-84-4  intermediate: 344396-19-6
Benvitimod 79338-84-4  intermediate: 1080-32-6
Benvitimod 79338-84-4  intermediate: 678986-73-7
Benvitimod 79338-84-4  intermediate: 55703-81-6
Benvitimod 79338-84-4  intermediate: 1190122-19-0
Benvitimod 79338-84-4  intermediate: 443982-76-1
Benvitimod 79338-84-4  intermediate: 100-52-72.ROS-Benvitimod

Name: Benvitimod
CAS#: 79338-84-4
Chemical Formula: C17H18O2
Exact Mass: 254.1307
Molecular Weight: 254.329
Elemental Analysis: C, 80.28; H, 7.13; O, 12.58


  1. ^ Joyce SA; Brachmann AO; Glazer I; Lango L; Schwär G; Clarke DJ; Bode HB (2008). “Bacterial biosynthesis of a multipotent stilbene”. Angew Chem Int Ed Engl47 (10): 1942–5. doi:10.1002/anie.200705148PMID 18236486.
  2. ^ Hu, K; Webster, JM (2000). “Antibiotic production in relation to bacterial growth and nematode development in Photorhabdus–Heterorhabditis infected Galleria mellonella larvae”. FEMS Microbiology Letters189 (2): 219–23. doi:10.1111/j.1574-6968.2000.tb09234.xPMID 10930742.
  3. ^ “New Topical for Mild to Moderate Psoriasis in the Works”Medscape. March 5, 2017.

///Benvitimod, Tapinarof, WBI-1001, тапинароф , تابيناروف , 他匹那罗 , Welichem Biotech, Stiefel Laboratories, Shenzhen Celestial Pharmaceuticals,CHINA 2019 , Psoriasis, Tianji Pharma, Dermavant Sciences, PHASE 3

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