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

Method for synthesizing 2-chloro-4-fluorobenzoic acid by using 2-chloro-4-aminobenzonitrile as raw material

A technology of aminobenzonitrile and fluorobenzoic acid, which is applied in nitrile preparation, carboxylate preparation, organic chemistry and other directions, can solve the problems of high risk of reaction reagents, low yield of synthetic products, expensive catalysts, etc., and avoid precious metals. Catalysts and highly toxic reagents, high yield, suitable for large-scale industrial production

Pending Publication Date: 2022-07-26
JIANGSU FLAG CHEM IND
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] In summary, the preparation methods have problems such as expensive raw materials, high risk of reaction reagents, expensive catalysts, and low yields of synthetic products.

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 synthesizing 2-chloro-4-fluorobenzoic acid by using 2-chloro-4-aminobenzonitrile as raw material
  • Method for synthesizing 2-chloro-4-fluorobenzoic acid by using 2-chloro-4-aminobenzonitrile as raw material
  • Method for synthesizing 2-chloro-4-fluorobenzoic acid by using 2-chloro-4-aminobenzonitrile as raw material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037]

[0038] ①Add 47.89g of 30% concentrated hydrochloric acid (molecular weight: 36.46, 394.01mmol, 3eq) and 20.0g of 2-chloro-4-aminobenzonitrile (molecular weight: 152.58, 131.08mmol, 1eq) to a 100mL four-necked flask, and the reaction solution was heated to Stir at 70°C for 0.5 hour. Cool down to 0°C, slowly add 129.23g sodium nitrite solution (69.00, 133.70mmol, 1.02eq, 9.23g sodium nitrite dissolved in 120g water) dropwise, after about 1h drop, keep stirring at 0°C for 0.5h, then 28.78 g of sodium tetrafluoroborate (molecular weight 109.79, 262.16 mmol, 2 eq) was added and stirred at a temperature for 0.5 h. The reaction solution was filtered, and the filter cake was dried in an oven at 60°C. In another 100 mL four-necked flask, add 50 mL of toluene and the dried filter cake, and heat up to 120° C. to react for 10 h. Toluene was spin-dried under negative pressure, 60 mL of dichloromethane was added, and the organic phase was washed with 40 mL of saturated ammoniu...

Embodiment 2

[0042]

[0043] ①Add 64.28g of 10% sodium hydroxide solution (molecular weight: 40, 160.71mmol, 5eq) and 5.0g of 2-chloro-4-fluorobenzonitrile (molecular weight: 155.56, 32.14mmol, 1eq) to a 100mL four-necked flask, and the temperature rises to 80 The reaction was stirred for 3 hours. The temperature was lowered to room temperature, extracted with 25 mL of ethyl acetate, the ethyl acetate phase was discarded, and the pH of the aqueous phase was adjusted to 2-3 with concentrated hydrochloric acid, at which point a white solid was precipitated. The aqueous phase was extracted three times with 40 mL of dichloromethane, the dichloromethane phases were combined, and 5.46 g of white solid was obtained by rotary drying under negative pressure. 90.02% (molecular weight 174.56, theory 5.61 g).

[0044]②Add 180.3g of 10% potassium hydroxide solution (molecular weight 56.1, 321.4mmol, 10eq) and 5.0g of 2-chloro-4-fluorobenzonitrile (molecular weight 155.56, 32.14mmol, 1eq) to a 100mL...

Embodiment 3

[0046] ①In a 100mL four-necked flask, add 35g of 90% sulfuric acid solution (molecular weight 98, 321.42mmol, 10eq) and 5g of 2-chloro-4-fluorobenzonitrile (molecular weight 155.56, 32.14mmol, 1eq) in turn. The temperature was raised to 100°C and the reaction was stirred for 4 hours. It was cooled to room temperature, diluted with 40 mL of water, extracted three times with 40 mL of dichloromethane, combined with the dichloromethane phases, and spin-dried under negative pressure to obtain 5.79 g of light yellow solid. -Fluorobenzoic acid, mass yield 93.05% (molecular weight 174.56, theoretical 5.61 g).

[0047] ②In a 100mL four-necked flask, add 16.58g of 95% sulfuric acid solution (molecular weight 98, 160.71mmol, 5eq) and 5g of 2-chloro-4-fluorobenzonitrile (molecular weight 155.56, 32.14mmol, 1eq) in turn. The temperature was raised to 90°C and the reaction was stirred for 12 hours. It was cooled to room temperature, diluted with 40 mL of water, extracted three times with ...

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 the field of organic synthesis, in particular to a method for synthesizing 2-chloro-4-fluorobenzoic acid by taking 2-chloro-4-aminobenzonitrile as a raw material, which comprises the following steps: carrying out diazotization reaction on 2-chloro-4-aminobenzonitrile to generate 2-chloro-4-fluorobenzonitrile; the 2-chloro-4-fluorobenzonitrile is hydrolyzed under an acidic condition to generate 2-chloro-4-fluorobenzoic acid, or the 2-chloro-4-fluorobenzonitrile is hydrolyzed under an alkaline condition to generate 2-chloro-4-fluorobenzoate; and the 2-chloro-4-fluorobenzoic acid salt is subjected to acidification so as to obtain the 2-chloro-4-fluorobenzoic acid. According to the method for synthesizing the 2-chloro-4-fluorobenzoic acid by using the 2-chloro-4-aminobenzonitrile as the raw material, provided by the invention, the use of an expensive noble metal catalyst and a highly toxic reagent is avoided, the used reagent is environment-friendly, the cost is reduced, the process is simplified, the yield is relatively high, the defects in the prior art are overcome, and the method is suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a method for synthesizing 2-chloro-4-fluorobenzoic acid by using 2-chloro-4-aminobenzonitrile as a raw material. Background technique [0002] 2-Chloro-4-fluorobenzoic acid is an important fine chemical intermediate, which is widely used in the fields of medicine and pesticides, especially, it is the key intermediate of the herbicide saflufenacil, which has huge market potential. [0003] About the synthesis technology of 2-chloro-4-fluorobenzoic acid, with reference to domestic and foreign literature, there are mainly the following methods: [0004] 1. The current domestic traditional synthesis process usually uses dichromate as an oxidant to oxidize 2-chloro-4-fluorotoluene to 2-chloro-4-fluorobenzoic acid, but dichromate is highly toxic and pollutes the environment. Serious, and the product yield is low. [0005] [0006] 2. Chinese patent CN105732357A uses m-chloroanili...

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): C07C51/08C07C63/70C07C51/02
CPCC07C51/08C07C51/02C07C253/30C07C63/70C07C255/50
Inventor 卜龙张璞骆文朱伟
Owner JIANGSU FLAG CHEM IND
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