农药关键中间体2-氯-5-甲基吡啶的合成研究

Study on the Synthesis of Pesticide Key Intermediate 2-Chloro-5-methylpyridine

以2-氨基-5-甲基吡啶为原料,经过重氮化反应生成2-氯-5甲基吡啶。考察了不同的亚硝酰氯制备方法、不同的反应温度、酸、溶剂对反应的影响。实验结果表明:选择氯化亚砜、水、硝酸制备亚硝酰氯,15~20℃、37%的盐酸是2-氨基-5-甲基吡啶最佳的重氮化反应条件,转化率100%,收率可达95%。

2-chloro-5-methylpyridine was produced by diazotization from 2-amino-5-methyl pyridine.The effects of different preparation methods of nitrosyl chloride,different reaction temperatures,acids and solvents on the reaction were investigated.The experimental results showed that the optimal reaction condition for diazotization of 2-amino-5-methylpyridine was preparing nitrosyl chloride with sulfoxide chloride,water and nitric acid at 15~20℃and using 37%hydrochloric acid.The conversion rate was 100%and the yield was 95%.