氯虫苯甲酰胺关键中间体2-氨基-5-氯-N,3-二甲基苯甲酰胺合成方法的改进

An Improved Synthesis of 2-Amino-5-chloro-N,3-dimethylbenzamide

[目的]研发适合工业化生产氯虫苯甲酰胺关键中间体2-氨基-5-氯-N,3-二甲基苯甲酰胺的工艺。[方法]以3-甲基-2-硝基苯甲酸为起始原料,经加氢、环合、胺解和氯化4步反应得到目标化合物。[结果]4步反应总收率为77.6%,产品含量为98.3%。[结论]该方法原料廉价易得、操作简单、反应条件温和,具有工业化应用前景。

[Aims] A synthetic method of 2-amino-5-chloro-N,3-dimethylbenzamide suitable on industrial scale was improved. [Methods] The title compound was synthesized from 3-methyl-2-nitro-benzoic acid via hydrogenation, cyclization, methylamination and chlorination. [Results] The total yield of the 4 synthetic steps reached 77.6% and the product purity reached 98.3%. [Conclusions] The improved method has such advantages as cheap and ready available raw materials, simple operations and warm reacting conditions. It is valuable to be used in industrial scale.