Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Preparation method of favipiravir

A technology of favipiravir and formamide, applied in the field of drug synthesis, to achieve the effects of less waste, low production cost and high yield

Active Publication Date: 2020-08-28
ENANTIOTECH CORP +1
View PDF4 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0016] In summary, there are still disadvantages in the application of the synthetic route of favipiravir in industrial production, which needs to be further improved

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of favipiravir
  • Preparation method of favipiravir
  • Preparation method of favipiravir

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0049] A preparation method of Favipiravir, comprising the following steps:

[0050] Step 1. Dissolving 6-bromo-3-hydroxypyrazine-2-carboxamide in the first solvent, adding the first fluorinating agent, stirring and reacting to prepare 6-bromo-3-fluoropyrazine-2-carboxamide;

[0051] Step 2. Dissolve the 6-bromo-3-fluoropyrazine-2-carboxamide, the second fluorinating agent and the catalyst in the second solvent, and heat the reaction to prepare 6-fluoro-3-fluoropyrazine-2- Formamide;

[0052] Step 3. Carrying out hydroxyl substitution to the 6-fluoro-3-fluoropyrazine-2-carboxamide to prepare Favipiravir.

[0053] Understandably, the synthetic route of the present invention is shown in the following formula:

[0054]

[0055] With 6-bromo-3-hydroxypyrazine-2-carboxamide as the starting material, 6-fluoro-3-fluoropyrazine-2-carboxamide was prepared by two fluorination reactions, and then, the 6- Fluoro-3-fluoropyrazine-2-carboxamide undergoes hydroxyl substitution to obtai...

Embodiment 1

[0080] This embodiment provides a kind of Favipiravir and its preparation method, the synthetic route and specific steps are as follows:

[0081] 1. Preparation of compound 2a

[0082]

[0083] Add 300ml of dichloromethane and 20g (0.0917mol) of 6-bromo-3-hydroxypyrazine-2-carboxamide into a 500ml three-necked flask, and cool the temperature of the material in the there-necked flask to 0°C under stirring, and add dropwise 15.5g ( 0.0963mol) DAST reagent, keep the temperature of the reaction solution at 0°C and stir for 5 hours after dripping, TLC detection, the color of the plate layer does not show the raw material point, stop the reaction, add 120ml process water to the reaction solution, stir for 0.5 hours after the addition, The material was transferred into a separatory funnel and left to stand for 1 hour. The organic phase was separated and concentrated to obtain 18.56 g of compound 2a with a molar yield of 92%. The obtained product was directly used in the next react...

Embodiment 2

[0092] This embodiment provides a kind of Favipiravir and its preparation method, which is basically the same as that of Example 1, the only difference is that the stirring reaction temperature is different, and the synthetic route and specific steps are as follows:

[0093] 1. Preparation of compound 2a

[0094]

[0095] Add 300ml of dichloromethane and 20g (0.0917mol) of 6-bromo-3-hydroxypyrazine-2-carboxamide into a 500ml three-necked flask, cool the material temperature in the there-necked flask to 20°C under stirring, and add dropwise 15.5g ( 0.0963mol) DAST reagent, keep the temperature of the reaction solution at 20°C and stir for 5 hours after dropping, TLC detection, the color of the plate layer does not show the raw material point, stop the reaction, add 120ml process water to the reaction solution, stir for 0.5 hours after the addition, The material was transferred into a separatory funnel and left to stand for 1 hour. The organic phase was separated and concentr...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a preparation method of favipiravir. The preparation method comprises the following steps: dissolving 6-bromine-3-hydroxypyrazine-2-formamide in a first solvent, adding a first fluorinating agent, and carrying out a stirring reaction so as to prepare 6-bromine-3-fluoropyrazine-2-formamide; dissolving the 6-bromo-3-fluoropyrazine-2-formamide, a second fluorinating agent anda catalyst in a second solvent, and carrying out a heating reaction to prepare 6-fluoro-3-fluoropyrazine-2-formamide; and carrying out hydroxyl substitution on the 6-fluoro-3-fluoropyrazine-2-formamide to prepare the favipiravir. The invention further discloses a preparation method of the favipiravir. The preparation method of favipiravir has the advantages of simple and safe reaction operation,less three wastes, green and environment-friendly synthetic route and environmental friendliness; the favipiravir has the advantages of higher yield, stability and low production cost, and is suitablefor industrial production.

Description

technical field [0001] The invention relates to the technical field of drug synthesis, in particular to a preparation method of Favipiravir. Background technique [0002] Favipiravir, chemical name: 6-fluoro-3-hydroxypyrazine-2-carboxamide, is mainly used in the treatment of new or re-popular influenza in adults, and has a good therapeutic effect on influenza virus, and has a good therapeutic effect on Bunia Viruses, yellow fever virus, West Nile virus and arenavirus are also effective. Its structural formula is as follows: [0003] [0004] At present, in the relevant reports on the synthesis of Favipiravir, its synthetic route is mainly as follows: [0005] Route 1: [0006] [0007] The above method is widely used in industry, among which 3,6-difluoro-2-cyanopyrazine is the key intermediate, however, the common 3,6-difluoro-2-cyano group in the synthetic route is: [0008] [0009] In this process, a large amount of phosphorus-containing wastewater and highly...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): C07D241/24
CPCC07D241/24
Inventor 卢彪蒙发明徐亮李彦雄胡骆祥陈舒婷
Owner ENANTIOTECH CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com