Check patentability & draft patents in minutes with Patsnap Eureka AI!

Preparation method of florasulam

A technology of florasulam and diflumezone, which is applied in the field of preparation of florasulam, can solve the problems of large consumption of reaction raw materials, high requirements for production conditions, and low yield, and achieve low production cost and high yield. High efficiency and mild reaction conditions

Pending Publication Date: 2022-02-18
ZHEJIANG ZHONGSHAN CHEM IND GRP
View PDF8 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a preparation method of florasulam, which solves the problems that the existing preparation process requires high production conditions, large consumption of reaction raw materials, and low yield

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

preparation example Construction

[0019] The invention provides a preparation method of florasulam, comprising the following steps:

[0020] Add 2-chlorosulfonyl-8-fluoro-5-methoxy[1,2,4]triazol[1,5-c]pyrimidine in dichloromethane to 2,6-difluoroaniline in alcohol , and then add an organic base, and react for 6-8 hours. After the reaction, the temperature is lowered, filtered, washed, and dried to obtain diflusulam.

[0021] In the present invention, the molar ratio of 2-chlorosulfonyl-8-fluoro-5-methoxy[1,2,4]triazol[1,5-c]pyrimidine to 2,6-difluoroaniline is preferably 1:1 to 1.7, more preferably 1:1.1 to 1.6, more preferably 1:1.4.

[0022] In the present invention, the methylene chloride solution of 2-chlorosulfonyl-8-fluoro-5-methoxy[1,2,4]triazol[1,5-c]pyrimidine is preferably 2-chlorosulfonyl- 8-Fluoro-5-methoxy[1,2,4]triazol[1,5-c]pyrimidine dissolved in dichloromethane.

[0023] In the present invention, the mass volume ratio of 2-chlorosulfonyl-8-fluoro-5-methoxy[1,2,4]triazol[1,5-c]pyrimidine and...

Embodiment 1

[0034] This embodiment provides a preparation method of florasulam, comprising the following steps:

[0035] 100 mL of 2-chlorosulfonyl-8-fluoro-5-methoxy[1,2,4]triazol[1,5-c]pyrimidine in dichloromethane (containing 2-chlorosulfonyl-8-fluoro -5-methoxy[1,2,4]triazol[1,5-c]pyrimidine 26.6g, 0.1mol) was added dropwise to 65mL of 2,6-difluoroaniline in 1,2-propanediol solution (containing 2, 6-Difluoroaniline (13g, 0.1mol), stir evenly, add 3-aminopyridine (28.24g, 0.3mol), react at 27°C for 6h, cool down to 10°C after the reaction, filter, and wash the filter residue with absolute ethanol , and dried at 60° C. for 7 hours to obtain 35.1 g of florasulam with a yield of 97.7% and a purity of 98.6%.

Embodiment 2

[0037] This embodiment provides a preparation method of florasulam, comprising the following steps:

[0038] 100 mL of 2-chlorosulfonyl-8-fluoro-5-methoxy[1,2,4]triazol[1,5-c]pyrimidine in dichloromethane (containing 2-chlorosulfonyl-8-fluoro -5-methoxy[1,2,4]triazol[1,5-c]pyrimidine 26.6g, 0.1mol) was added dropwise to 60mL of 2,6-difluoroaniline in 1,2-propanediol solution (containing 2, 6-difluoroaniline (16.8 g, 0.13 mol), stir evenly, add pyridine (7.91 g, 0.1 mol), react at 20 °C for 6.5 h, cool down to 8 °C after the reaction, filter, and wash the filter residue with absolute ethanol, After drying at 80°C for 7 hours, 34.76 g of florasulam was obtained with a yield of 96.7% and a purity of 97.4%.

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 belongs to the technical field of herbicides, and discloses a preparation method of florasulam. The method comprises the following steps: adding a dichloromethane solution of an intermediate product sulfonyl chloride into an alcoholic solution of 2, 6-difluoroaniline, then adding organic alkali, reacting for 6-8 hours, and after the reaction is finished, cooling, filtering, washing and drying to obtain florasulam, wherein the organic base is one or more of triethylamine, pyridine, 3-aminopyridine, tetrabutylammonium bromide and N-methyl dicyclohexylamine. According to the invention, the organic alkali is used as an acid-binding agent, so that the dosage of the reaction raw material 2, 6-difluoroaniline is reduced, and the molar equivalents of the intermediate product sulfonyl chloride and the 2, 6-difluoroaniline are equivalent during the condensation reaction, so that the problem of excessive consumption of the 2, 6-difluoroaniline in the traditional condensation reaction is solved; and the reaction conditions are mild, the reaction can be carried out at room temperature or lower heating temperature, and industrial large-scale production can be realized.

Description

technical field [0001] The invention relates to the technical field of herbicides, in particular to a preparation method of florasulam. Background technique [0002] Florasulam is a triazolopyrimidine sulfonamide herbicide, its chemical name is 2',6'-difluoro-5-methoxy-8-fluoro[1,2,4]triazole [1,5-c]pyrimidine-2-sulfonylanilide, originally developed by Dow Agroscience Company of the United States, is highly selective to weeds in wheat fields and is widely used as a herbicide in wheat cultivation. [0003] At present, the domestic synthesis method for florasulam mainly uses 5-fluorouracil as the starting material, followed by chlorination reaction, methoxylation reaction, hydrazinylation reaction, cyclization reaction, transposition reaction, and coupling reaction , oxidation reaction and condensation reaction to obtain the final product. For the condensation reaction in the last step, the traditional process needs to use a large amount of 2,6-difluoroaniline and sulfonyl c...

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): C07D487/04
CPCC07D487/04Y02E60/10
Inventor 高雪娇张云云杜亮亮郑军
Owner ZHEJIANG ZHONGSHAN CHEM IND GRP
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