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

A preparing method of 2,4-dichloro-5-sulfamoylbenzoic acid

A technology of sulfonamide benzoic acid and dichlorobenzoic acid, which is applied in the field of preparation of pharmaceutical intermediates, can solve problems such as the decline in synthesis yield and the health hazards of employees, and achieve the goals of controlling production costs, increasing safety factors, and preventing side reactions Effect

Inactive Publication Date: 2015-06-03
门修信
View PDF0 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are following problems in the method for present traditional synthetic 2,4-dichloro-5-sulfonamide benzoic acid: 1. in the reaction process, due to the generation of side reaction, the by-product that brings makes synthetic yield decline; 2. in the reaction process Using dimethyl sulfoxide as a solvent is easy to be oxidized to produce by-products due to its low boiling point; 3. Using acetone as a refined solvent will bring harm to the health of front-line workers

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The preparation method of 2,4-dichloro-5-sulfonamide benzoic acid of the present invention comprises the following steps:

[0018] (1) Sulfonation: use 2,4-dichlorobenzoic acid and chlorosulfonic acid as raw materials, and sodium sulfate as a catalyst; first add N-methylpyrrolidone into the reaction kettle, then add 2,4-dichlorobenzoic acid and Sodium sulfate, heat the material to 145 ° C, after the material is completely dissolved, start to add chlorosulfonic acid dropwise, and keep warm for 5 hours after the dropwise addition;

[0019] (2) Centrifugation: cool down the reacted material in step (1) to room temperature, centrifuge the product, and recover the solvent to obtain the intermediate 2,4-dichloro-5-carboxybenzenesulfonyl chloride;

[0020] (3) Ammonification: Put the ammonia water into the ammoniation kettle, open the jacket of the ammoniation kettle, cool down with ice salt, wait until the temperature of the ammonia water in the kettle drops to 0°C, slowly ad...

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 preparing method of a medicine intermediate, and particularly relates to a preparing method of 2,4-dichloro-5-sulfamoylbenzoic acid. The method includes performing sulfurization by adopting 2,4-dichlorobenzoic acid and chlorosulfonic acid as initial raw materials, sodium sulfate as a catalyst and NMP as a solvent; centrifuging to obtain 2,4-dichloro-5-carboxybenzenesulfonyl chloride; subjecting the 2,4-dichloro-5-carboxybenzenesulfonyl chloride to ammoniation with ammonia water; acidifying; washing with water to obtain a crude product of the 2,4-dichloro-5-sulfamoylbenzoic acid; purifying the crude product with ethanol; and recrystallizing to obtain a 2,4-dichloro-5-sulfamoylbenzoic acid product with high quality. The method is less in process steps, easily available in raw materials, low in pollution, high in product purity and low in cost, and is a green synthesis route.

Description

technical field [0001] The invention belongs to a preparation method of a pharmaceutical intermediate, in particular to a preparation method of 2,4-dichloro-5-sulfonamide benzoic acid. Background technique [0002] 2,4-dichloro-5-sulfonamide benzoic acid, the English name Lasamide, is an important intermediate of furosemide. Furosemide, also known as furosemide and diuretic, is suitable for primary and secondary hypertension, especially for elderly patients with hypertension or complicated by heart failure. It is clinically used to treat peripheral edema caused by cardiac edema, renal edema, liver cirrhosis ascites, dysfunction or vascular disorder, and can promote the discharge of upper urinary tract stones. Its diuretic effect is rapid and powerful, and it is mostly used in severe cases where other diuretics are ineffective. There are following problems in the method for present traditional synthetic 2,4-dichloro-5-sulfonamide benzoic acid: 1. in the reaction process, du...

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
IPC IPC(8): C07C311/16C07C303/38C07C303/44
Inventor 门修信
Owner 门修信
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