Preparing fipronil involves oxidizing 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-cyano-4-trifluoromethyl thio pyrazole in medium of oxidizing agent e.g. hydrogen peroxide, solvent system and boric acid

摘要

Preparing 5-amino-1-(2,6-dichloro-4-trifluoromethyl phenyl)-3-cyano-4-trifluoromethyl sulfinyl pyrazole (I) involves oxidizing 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-cyano-4-trifluoromethyl thio pyrazole (II) in a medium comprising at least one oxidizing agent selected from hydrogen peroxide, tert butyl hydrogen peroxide, benzoyl peroxide and sodium peroxide, a solvent system and boric acid as a corrosion inhibiting compound.