氟虫腈合成工艺的研究

以对氯三氟甲苯为起始原料,经硝化、氯代制得3,4,5-三氯三氟甲苯,通过路线选择,最终选定肼解还原法制得中间体2,6-二氯-4-三氟甲基苯胺,各步产率均在90%以上。经重氮化制得的重氮盐与2,3-二氰基丙酸乙酯缩合后,在碱性条件下,闭环制得3-氰基-5-氨基-1-(2,6-二氯-4-三氟甲基苯基)吡唑,再经一步反应制得氟虫腈。反应总产率可达38.8%,纯度95%。各步产物经红外、质谱、核磁表征,证明结构正确。

Research on the Synthesis Crafts of Fipronil

This article related to a procedure for the preparation of fipronil.Firstly, using p-chlorobenzotrifloride as the starting material, 3,4,5-trichlorobenzotrifluoride was prepared by nitrafication and chlorination. Chosing from three methods, we determined to use hydrozinolysis and hydrogenolysis reduction route to prepare the intermediate 2,6-dichloro-4-trifluoromethylaniline. The yield of each step was higher than 90%. After the intermediate becoming diazonium salt, the salt reacted with ethyl 2,3-dicyano propionate, and in the presence of ammonia, 5-amino-3-cyano-1- （2,6-dichlorine-4-trifluoromethylbenzyl）pyrazole was obtained by ring-closing reaction, Finally, using one step to achieve fipronil. The total yield reached 38.8%, product purity was 95%. The structure of the compound was characterized by IR, 1^HNMR, MS and it proved the structure was correct.