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

Preparation method of 5, 6-dimethylbenzimidazole

A technology of dimethylbenzimidazole and dimethylphenyl, which is applied in the field of preparation of 5,6-dimethylbenzimidazole, can solve problems such as complicated operation, achieve simple operation, shorten synthesis steps, and overcome defects and insufficient effect

Inactive Publication Date: 2021-06-04
河北凡博医药科技有限公司
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The process involves protection and deprotection, and the operation is cumbersome

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 5, 6-dimethylbenzimidazole
  • Preparation method of 5, 6-dimethylbenzimidazole

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0017] See attached figure 2 , a preparation method of 5,6-dimethylbenzimidazole, comprising the following steps.

[0018] Step A. Preparation of N-(3,4-dimethylphenyl)formamide: Add 3,4-dimethylaniline into the flask, raise the temperature to 50-90°C, add formic acid dropwise into the flask and react 0.1-3 hours, and then evaporated to dryness under reduced pressure to obtain N-(3,4-dimethylphenyl)formamide.

[0019] Wherein, the ratio of 3,4-dimethylaniline and formic acid added to the flask is 1:1~1:5.

[0020] Step B, preparation of N-(4,5-dimethyl-2-nitrophenyl) formamide: N-(3,4-dimethylphenyl) formamide, reaction solvent and concentrated nitric acid were added to In the flask, react at 0-25°C for 1-10 hours. After the reaction is completed, add ice water to the system dropwise, stir, filter, and dry to obtain N-(4,5-dimethyl-2-nitrophenyl ) Formamide.

[0021] Wherein, the reaction solvent is concentrated sulfuric acid, glacial acetic acid or dichloromethane, and t...

Embodiment 1

[0029] Example 1: Add 3,4-dimethylaniline (121.2g, 1mol) into the flask, raise the temperature to 55°C, after it is completely dissolved, add formic acid (46.1g, 1mol) dropwise, and after 10min, reduce the temperature at 80°C Pressure distillation and evaporation to dryness gave 149.1 g of an oily liquid with a yield of 99.9% and an HPLC purity of 99.6%.

Embodiment 2

[0030] Example 2: Add 3,4-dimethylaniline (121.2g, 1mol) into the flask, raise the temperature to 75°C, after it is completely dissolved, add formic acid (46.1g, 1mol) dropwise, and after 10min, reduce the temperature at 80°C Pressure distillation and evaporation to dryness gave 147.1 g of an oily liquid with a yield of 98.6% and an HPLC purity of 99.7%.

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 discloses a preparation method of 5, 6-dimethyl benzimidazole. The preparation method comprises the following four steps: preparation of N-(3, 4-dimethyl phenyl) formamide, preparation of N-(4, 5-dimethyl-2-nitrophenyl) formamide, preparation of N-(2-amino-4, 5-dimethyl phenyl) formamide, and preparation of 5, 6-dimethyl benzimidazole. The preparation method has the following beneficial effects: 1, acetylation and deacetylation used in the prior art are avoided, which is in favor of environmental protection; 2, the synthesis steps of the process are shortened, the original five-step reaction is shortened to the present four-step reaction, and the yield is improved; and 3, the purity of the intermediate is high, separation is not needed, the operation is simple, the defects and deficiencies of the preparation method reported in the literature are overcome, and the method has novelty, greater positive progress effect and practical application value.

Description

technical field [0001] The invention relates to a preparation method of 5,6-dimethylbenzimidazole. Background technique [0002] Vitamin B 12 It is a general term for a class of cobalt-containing corrin compounds. China is now vitamin B 12 The main producing area of ​​China, the sales in 2019 will be about 500 tons, accounting for 80% of the global sales market. 5,6-Dimethylbenzimidazole is an important intermediate in the fermentation process of vitamin B12, and the domestic demand is about 400 tons per year. The existing process of 5,6-dimethylbenzimidazole uses 3,4-dimethylaniline as a starting material, through acetylation, nitration, reduction and deprotection, and a total of 5 steps of ring closure (such as figure 1 Shown, Advances in Science and Technology, 1999, 10: 19-22). The process involves protection and deprotection, and the operation is cumbersome. Contents of the invention [0003] The technical problem to be solved in the present invention is to prov...

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): C07D235/06
CPCC07D235/06
Inventor 刘育王天峰李仕恒刘子博
Owner 河北凡博医药科技有限公司
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