Synthesis method of 2-amino-5-chloro-N,3-dimethylbenzamide

Abstract

The invention discloses a synthesis method of 2-amino-5-chloro-N,3-dimethylbenzamide, belonging to the technical field of organic chemical synthesis. The method comprises the following steps: carrying out oxidation under the catalytic actions of N-hydroxyphthalimide and cobalt acetylacetonate to generate benzoic acid, carrying out substitution reaction with chlorine gas to generate 3,5-dichlorobenzoic acid, shielding off 5- chlorine by using a shielding reagent, carrying out methyl substitution on the 5- chlorine by using a Grignard reagent to generate 3-methyl-5-chlorobenzoic acid, carrying out nitro-substitution on the 3-methyl-5-chlorobenzoic acid and nitric acid under the catalytic action of concentrated sulfuric acid to generate 2-nitro-3-methyl-5-chlorobenzoic acid, carrying out catalytic hydrogenation to reduce the nitro group into amino group, carrying out reaction under the actions of N,N'-diisopropylcarbodiimide and 1-hydroxybenztriazole to obtain an intermediate, and carrying out reaction on the intermediate and methylamine to obtain the 2-amino-5-chloro-N,3-dimethylbenzamide. The method is simple to operate, and obviously enhances the synthesis yield to 92% or above.

Description

technical field [0001] The invention discloses a synthesis method of 2-amino-5-chloro-N,3-dimethylbenzamide, which belongs to the technical field of organic chemical synthesis. Background technique [0002] Chlorantraniliprole is a ryanodine receptor inhibitor insecticide developed by DuPont. This type of insecticide not only has good activity against Lepidoptera pests, but also has no mutual resistance with existing insecticides , and is safe for mammals, showing the characteristics of high efficiency, broad spectrum, long-lasting effect and novel mechanism of action, so it has broad application space and huge market prospects. 2-Amino-5-chloro-N, 3-dimethylbenzamide is an important intermediate for the synthesis of chlorantraniliprole, and there are few reports in the literature related to it. There is no production process in China, and an economically feasible The synthetic process route is of great significance to the industrial production of chlorantraniliprole in Chi...

AI Technical Summary

Problems solved by technology

[0003] The technical problem mainly solved by the present invention: for the synthesis of 2-amino-5-chloro-N, 3-dimethylbenzamide, the operation is complex, the production cost is high, the total yield is low, and the maximum is only 84%. Provide a kind of synthetic method of 2-amino-5-chloro-N,3-dimethylbenzamide, the present invention is to be raw material with toluene, at first in N-hydroxyphthalimide and cobalt acetylacetonate Oxidation to benzoic acid under the catalysis of the catalyst, and then catalyzing chlorine gas to replace the benzene ring to obtain 3,5-dichlorobenzoic acid, and then generate 3-methyl-5-chlorobenzoic acid through the action of shielding reagent and Grignard reagent Then under the catalysis of concentrated sulfuric acid, react with chlorine nitrate to generate 2-amino-3-methyl-5-chlorobenzoic acid, and finally use N, N'-diisopropylcarbodiimide as a condensation agent, 1-hydroxybenzene Triazole is used as a condensation activator to obtain an intermediate and then react with methylamine to generate 2-amino-5-chloro-N, 3-dimethylbenzamide. The present invention not only has simple operation and few steps, but also has a high synthesis yield. Significantly improved, increased to more than 92%