Preparation method for 3- (2-chloro-4- (trifluoromethyl) phenoxy) -benzoic acid

A technology of trifluoromethyl and m-hydroxybenzoic acid, applied in carboxylate preparation, organic chemistry, etc., can solve the problems of low yield and long reaction cycle, and achieve high yield, short reaction cycle and reduced dosage Effect

Active Publication Date: 2014-12-17
JINGBO AGROCHEM TECH CO LTD
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The above synthesis methods are all heterogeneous reactions, and generally have the problems of long reaction cycle and low yield (90%-94%)

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 for 3- (2-chloro-4- (trifluoromethyl) phenoxy) -benzoic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] In a 500mL flask, add 60g (0.426mol) of m-hydroxybenzoic acid, 58g (0.936mol) of potassium hydroxide, 3.6g of 15-crown-5, 240g of dimethyl sulfoxide, and 120g of toluene. Slowly add 110.9g (0.511mol) of 3,4-dichlorobenzotrifluoride. After the addition, the temperature is raised to 130-140°C, and the reaction is kept for 6 hours. The residual hydroxybenzoic acid is 0.88%. Add water to dissolve, acidify with hydrochloric acid to pH = 1, filter and dry to obtain 136.3g (0.410mol) of product 3-(2-chloro-4-(trifluoromethyl)phenoxy)-benzoic acid, content 95.1%, yield The rate is 96.3%.

Embodiment 2

[0022] In a 500mL flask, add 60g (0.426mol) of m-hydroxybenzoic acid, 54g (0.871mol) of potassium hydroxide, 2.4g of 18-crown-6, 180g of dimethyl sulfoxide, and 200g of toluene. Slowly add 101.7g (0.468mol) of 3,4-dichlorobenzotrifluoride. After the addition, the temperature is raised to 135-150°C, and the reaction is kept for 6.5 hours. The residue of hydroxybenzoic acid reaches 0.95%. After adding water to dissolve, acidify with hydrochloric acid to pH = 1, and finally filter and dry to obtain the product 3-(2-chloro-4-(trifluoromethyl)phenoxy)-benzoic acid 137.5g (0.416mol), content 95.5% , yield 97.5%.

Embodiment 3

[0024] In a 500mL flask, add 60g (0.426mol) m-hydroxybenzoic acid, 60.6g (0.98mol) potassium hydroxide, 200g dimethyl sulfoxide, 180g toluene and stir, add 3.0g 18-crown-6 in batches within 1 hour, add After completion, heat up and reflux until no water is taken out. Slowly add 106.3g (0.489mol) of 3,4-dichlorobenzotrifluoride. After the addition, the temperature is raised to 135-155°C, and the reaction is kept for 6 hours. The residue of hydroxybenzoic acid reaches 0.93%. After adding water to dissolve, acidify with hydrochloric acid to pH = 1, and finally filter and dry to obtain the product 3-(2-chloro-4-(trifluoromethyl)phenoxy)-benzoic acid 138.5g (0.417mol), content 95.1% , yield 97.9%.

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 chemical synthesis, and relates to the phase transfer catalytic preparation technology. A crown-ether phase transfer catalyst is used to promote the chemical reaction, and chemical equilibrium is promoted by timely removing water generated in a system by toluene in the expected direction. A preparation method for 3- (2-chloro-4- (trifluoromethyl) phenoxy) -benzoic acid includes performing salt-forming reaction in a crown-ether catalyst and a dimethylsulfoxide / toluene mixed solvent, then performing etherification with 3, 4-dichlorobenzotrifluoride at 130-175 DEG C, and finally performing acidification to the etherate to obtain the 3- (2-chloro-4- (trifluoromethyl) phenoxy) -benzoic acid. The preparation method for the 3- (2-chloro-4- (trifluoromethyl) phenoxy) -benzoic acid has the advantages that yield is over 96%, chemical reaction rate is increased evidently, reaction period is short, the product is easy to separate, environmental pollution is low, and industrial application prospect is broad.

Description

1. Technical field [0001] The invention belongs to the technical field of chemical synthesis, and relates to a phase transfer catalysis preparation technology, in particular to a phase transfer catalysis salt formation technology. 2. Background technology [0002] Acifluorfen, acifluorfen, and fomesafen are widely used diphenyl ether herbicides in soybean fields, which can control most broad-leaved weeds and some grass weeds. 3-(2-Chloro-4-(trifluoromethyl)phenoxy)-benzoic acid is widely used as an intermediate in the synthesis of herbicides acifluorfen, acifluorfen, and fomesafen application. [0003] 3-(2-Chloro-4-(trifluoromethyl)) introduced by Lu Yang in the article "Synthesis Technology of Soybean Herbicide Fomesafen" ("Anhui Agricultural Science Bulletin", 2006, 12(12), 122) Phenoxy)-benzoic acid as an intermediate, using 3,4-dichlorotrifluorotoluene in dimethyl sulfoxide solvent at 110°C to form a heterogeneous salt, then cooling down and adding m-hydroxybenzoic ac...

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 Patents(China)
IPC IPC(8): C07C65/24C07C51/02
Inventor 王建刚韦能春王宗曹同波戴荣华苑敬林郝春艳
Owner JINGBO AGROCHEM TECH CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap