FIPRONIL PRODUCTION PROCESS

摘要

An improved oxidation process for preparing 5-amino-3-cyano-1- (2,6-dichloro-4-trifluoromethylphenyl) -4-trifluoromethylsulphinyl-pyrazole, of formula (I) is described. The process includes admixing 5-amino-3-cyano-l- (2, 6-dichloro-4-trifluoromethylphenyl) -4-trifluoromethylthiopyrazole of formula (II) with dichloroacetic acid and hydrogen peroxide in the presence of a strong acid.