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, which belongs to the technical field of organic chemical synthesis. The present invention uses toluene as a raw material, first under the catalysis of N-hydroxyphthalimide and cobalt acetylacetonate, oxidizes to generate benzoic acid, then generates 3,5-dichlorobenzoic acid through a substitution reaction with chlorine, and then Shield the 5-position chlorine with a shielding reagent, use a Grignard reagent to replace the 3-position chlorine with a methyl group to generate 3-methyl-5-chlorobenzoic acid, and then nitro-substitute with nitric acid under the catalysis of concentrated sulfuric acid to generate 2-nitro ‑3‑methyl‑5‑chlorobenzoic acid, followed by catalytic hydrogenation to reduce the nitro group to an amino group, and finally in the action of N,N'‑diisopropylcarbodiimide and 1‑hydroxybenzotriazole The intermediate is obtained by reacting the intermediate with methylamine to obtain 2-amino-5-chloro-N, 3-dimethylbenzamide. The present invention is not only simple to operate, but also the synthesis yield has been significantly improved, reaching 92 %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%