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The preparation method of 2-chloro-3-methylbenzoic acid and its intermediate

A technology of toluic acid and dimethyl chloroformic acid, which is applied to the preparation of phosgene or haloformate, carboxylate, and organic compounds, and can solve the problems of difficult implementation of industrial production, strict equipment requirements, and reaction problems. Poor selectivity and other problems, to achieve the effect of easy industrial production, high industrial value, and mild reaction conditions

Active Publication Date: 2021-09-24
LIANHE CHEM TECH +4
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] The technical problem to be solved by the present invention is in order to overcome the expensive raw material in the preparation method of existing 2-chloro-3-methylbenzoic acid, poor reaction selectivity, be difficult to separate, product purity is low, poor quality, yield is low, and reaction The process uses concentrated nitric acid and concentrated sulfuric acid, produces a large amount of acidic waste water, has strict requirements on equipment, great environmental pollution, high production costs, so that industrial production is difficult to implement, etc., thus providing a 2-chlorine that is completely different from the prior art -The preparation method of 3-methylbenzoic acid and its intermediate

Method used

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  • The preparation method of 2-chloro-3-methylbenzoic acid and its intermediate
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  • The preparation method of 2-chloro-3-methylbenzoic acid and its intermediate

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Effect test

Embodiment 1

[0080] Preparation of 2-amino-3-methylbenzoic acid

[0081] Step 1 2, the preparation of 6-dimethyl phenyl chloroformate

[0082] Add 122g (1.0mol) of 2,6-dimethylphenol, 18.3g of DMF, and 488g of toluene to a 1L four-necked flask. During the aerobic process, keep the temperature of the reaction system between 50 and 60°C, react for 2 hours, and detect that the raw material is less than 0.5%, and the reaction is complete; cool down the reaction kettle to room temperature, let it stand for 30 minutes, filter out the supernatant liquid, and keep the solid in the bottle Apply to the next batch of reactions. The supernatant was decompressed to remove toluene, and the toluene was directly applied to the next batch of reactions; the supernatant obtained after decompression toluene was removed from the concentrated solution was sampled, the mass content of the test was 98.5%, the concentrated solution weighed 184g, and the calculated yield was 98.2% . The crude product was directl...

Embodiment 2

[0089] In the L four-necked bottle, add 122g (1.0mol) 2,6-dimethylphenol, 18.3g pyridine or the solid after pyridine catalytic reaction, and 488g toluene. (2.0mol) phosgene, during the process of passing phosgene, keep the temperature of the reaction system between 50-60°C, react for 2 hours, and detect the raw material <0.5%, the reaction is complete; cool the reaction kettle to room temperature, let it stand for 30min, and filter out The supernatant and the solid were left in the bottle and applied to the next batch of reactions. The toluene was removed from the supernatant under reduced pressure, and the toluene was directly applied to the next batch of reactions; the crude concentrate was sampled, and the mass content of the concentrate was 62.7%. The concentrate weighed 180g, and the calculated yield was 61.2%.

Embodiment 3

[0091] In a 1L four-necked flask, add 122g (1.0mol) 2,6-dimethylphenol, 18.3g pyridine or the solid after pyridine catalytic reaction, and 488g toluene. (2.0mol) phosgene, during the process of passing phosgene, keep the temperature of the reaction system between 50-60°C, react for 2 hours, and detect the raw material <0.5%, the reaction is complete; cool the reaction kettle to room temperature, let it stand for 30min, and filter out The supernatant and the solid were left in the bottle and applied to the next batch of reactions. The toluene was removed from the supernatant under reduced pressure, and the toluene was directly applied to the next batch of reactions; the crude concentrate was sampled, and the mass content of the concentrate was 62.7%. The concentrate weighed 180g, and the calculated yield was 61.2%.

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Abstract

The invention discloses a preparation method of 2-chloro-3-methylbenzoic acid and its intermediate. A preparation method for 2-chloro-3-methylbenzoic acid and intermediates thereof, comprising the following steps, under the condition of oxygen pressure of 0.1MPa~0.8MPa, under the action of catalyst and promoter, 2,6- The dimethyl chlorobenzene can be oxidized; wherein, the molar ratio of the 2,6-dimethyl chlorobenzene to the oxygen is 1:1.8-1:2.2. The preparation method of the 2-chloro-3-methylbenzoic acid is reacted with raw materials that are relatively easy to purchase in industry, and has simple aftertreatment, high yield, good purity, less environmental pollution, and is more suitable for industrialization.

Description

technical field [0001] The present invention relates to the preparation method of 2-chloro-3-methylbenzoic acid and its intermediate. Background technique [0002] Chlorobenzoic acid compounds are a class of important chemical intermediates, which are widely used in the synthesis of pesticides, medicines and fine chemicals. Among them, 2-chloro-3-methylbenzoic acid is an important intermediate for the synthesis of a new generation of insecticide chlorantraniliprole, and can also be used for the synthesis of various folic acid analogs and anticancer drugs. [0003] The methods of synthesizing 2-chloro-3-methylbenzoic acid reported at home and abroad are mainly diazo hydrogenation method and butyllithium method. Specifically, (1) diazo hydrogenation method: as the patent document U.S. Patent 20070021427, 25Jan2007 reported the following preparation method: [0004] [0005] In the above diazo hydrogenation method, the yield of the first step of esterification is 86%, the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C67/39C07C69/76C07C25/125C07C17/363C07C68/02C07C69/96
CPCC07C17/363C07C67/39C07C68/02C07C69/76C07C25/125C07C69/96
Inventor 陈建国郭章红江朋陈庆忠杨晓敏
Owner LIANHE CHEM TECH
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