清洁溶剂应用于吡虫啉合成工艺中研究

Study of Cleaning Solvents Used in The Synthesis of imidacloprid

以2-氯-5-氯甲基吡啶为原料,用清洁溶剂乙醇代替乙腈,采用硝基胍法对吡虫啉的合成进行了工艺改进。考察了溶剂、温度、原料配比、时间等因素对反应的影响。获得以乙醇为溶剂的最佳合成工艺条件:反应温度40℃,原料配比n乙二胺:n2-氯-5-氯甲基吡啶=2:1,反应时间为3 h,得到中间体2-氯-5-甲基吡啶乙二胺的产率为75.5%,纯度为95.30%。

We improved the synthesis of imidacloprid by means of nitroguanidine method using 2-chloro-5-chloromethylpyridine as raw material,cleaning solvents ethanol instead of acetonitrile.Meanwhile the effects of solvent,temperature,raw material ratio,time on the reaction was studied,and we have got the optimum conditions： ethanol as solvent,reaction temperature 40 ℃,the molar ratio n ethylenediamine： n2-chloro-5-chloromethyl pyridine = 2：1,reaction time is 3h.The yield of intermediate 2-chloro-5-methylpyridine was 75.5% withing purity of 95.30%.