Supercharge Your Innovation With Domain-Expert AI Agents!

Method for greatly reducing amount of solvent usage in production process of oxfendazole

A production process and usage technology, which is applied in the field of greatly reducing the solvent usage in the production process of ofendazole, can solve the problems of increasing the solvent amount, difficult to tolerate the precipitation of crystals of B crystal form, uneconomical, etc., and achieves the reduction of solvent usage. Quantity, process operation is simple, the effect of saving the amount of use

Inactive Publication Date: 2013-01-09
JIANGSU BAOZONG & BAODA PHARMACHEM
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The fenbendazole produced by the existing technology mainly exists in the A crystal form, so when fenbendazole is just put into the solvent, it is relatively easy to dissolve, but in the solution state, a small number of crystal nuclei of the B crystal form will be generated very quickly, thereby Induced crystallization, resulting in the precipitation of a large amount of intolerant Form B crystals
In order to prevent a large amount of solid precipitation in the reaction from affecting the reaction, the only way to increase the amount of solvent is to increase the amount of solvent. Generally, the amount of solvent used is 3 to 4 times that of the material. A large amount of solvent is used and cannot be used, which is neither economical nor environmentally friendly.

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
  • Method for greatly reducing amount of solvent usage in production process of oxfendazole

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Add 100.0g fenbendazole and 400.0g formic acid to a 1000ml four-necked flask with a thermometer and a stirring device. Start stirring. After the materials are dissolved, start adding 41.3Kg of hydrogen peroxide (concentration 27.5%) dropwise, and keep the temperature at 20. ~25℃, the dripping is completed in about 1.5 hours. After the addition of hydrogen peroxide is completed, 100.0 fenbendazole is added to the reaction system. After the added fenbendazole is dissolved, 57.8Kg of hydrogen peroxide (concentration of 27.5%) is added. ), the temperature is maintained at 20-25℃, and the dripping is completed in about 1.5 hours. After the addition of hydrogen peroxide is completed, take samples and control them. After the reaction is over, 70.0 g of sodium sulfite aqueous solution (concentration 16.5%) is added to the system to quench the reaction. Then the solvent was concentrated by distillation under reduced pressure. After the solvent was distilled, 600g of methanol was ...

Embodiment 2

[0022] Add 100.0g fenbendazole and 400.0g mixed solvent (ethanol:concentrated sulfuric acid=20:1) into a 1000ml four-necked flask with a thermometer and a stirring device. When the materials are dissolved, start adding 41.3Kg of hydrogen peroxide ( The concentration is 27.5%), the temperature is kept at 20~25℃, and the dripping is completed in about 1.5 hours. After the addition of hydrogen peroxide is completed, 100.0 fenbendazole is added to the reaction system. After the added fenbendazole is dissolved, start Add 57.8Kg of hydrogen peroxide (concentration of 27.5%) dropwise, keep the temperature at 20-25°C, and complete the dropwise addition in about 1.5 hours. After the addition of hydrogen peroxide dropwise, the sampling is controlled, and after the reaction is over, 70.0 g of sodium sulfite aqueous solution (concentration 16.5%) is added to the system to quench the reaction. Then 41.0g of ammonia water (concentration of 25.0%) was added dropwise to the reaction system, an...

Embodiment 3

[0024] Add 100.0g of fenbendazole and 400.0g of mixed solvent (ethanol:chloroform:concentrated hydrochloric acid=2:2:1) into a 1000ml four-necked flask with a thermometer and a stirring device. Add 41.3Kg of hydrogen peroxide (concentration of 27.5%), keep the temperature at 20-25°C, and complete the dripping in about 1.5 hours. After the dripping of hydrogen peroxide is completed, add 100.0 fenbendazole to the reaction system, and the fenbendazole to be added After the azole is dissolved, start to add 57.8Kg of hydrogen peroxide (concentration 27.5%) dropwise, keep the temperature at 20-25°C, and complete the dropwise addition in about 1.5 hours. After the addition of hydrogen peroxide dropwise, the sampling is controlled, and after the reaction is over, 70.0 g of sodium sulfite aqueous solution (concentration 16.5%) is added to the system to quench the reaction. Then 65.0g of ammonia water (concentration of 25.0%) was added dropwise to the reaction system, and the solvent was...

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 method for greatly reducing amount of solvent usage in the production process of oxfendazole. The method is characterized by comprising the step of taking fenbendazole as a starting raw material and the hydrogen peroxide as the oxidant to produce oxfendazole, however, the fenbendazole has low dissolubility, and lots of solvents are adopted and cannot be recovered, which lead to high technology cost and environmental protection cannot be achieved. According to the method disclosed by the invention, the feeding sequence, the feeding way, the amount of fed materials, and the time of feeding are skillfully designed based on the characteristic of the material in crystal transfer; and the amount of the solvent usage can be greatly saved; and the method is simple and convenient in technological operation, economic and environment-friendly, and suitable for industrial production.

Description

Technical field [0001] The invention relates to a method for greatly reducing the amount of solvent used in the production process of oxfendazole, in particular to the improvement of the feeding process, and is an ingenious and innovative feeding process design. Background technique [0002] Oxfendazole is a derivative of fenbendazole. It is a broad-spectrum, high-efficiency and low-toxicity anti-helminth drug. Its anthelmintic spectrum is roughly the same as that of fenbendazole, but its anthelmintic activity is stronger. Bendazole is a raw material, and hydrogen peroxide is used as an oxidant. It is synthesized through oxidation reaction. The reaction formula is as follows: [0003] . [0004] Due to the poor solubility of fenbendazole, the solvent used in the reaction process is large and cannot be recovered. After research, we found that the poor solubility of fenbendazole is mainly due to the existence of two crystal forms of fenbendazole, A and B, of which crystal form B is ...

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): C07D235/32
Inventor 严家庆朱志勇王琳端卫明
Owner JIANGSU BAOZONG & BAODA PHARMACHEM
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

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

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com