Process for the preparation of 5-phenylsulfinyl-1H-2-(methoxycarbonylamino)-benzimidazole

摘要

A highly selective, inexpensive and quantitative process is described for the preparation of 5-phenylsulfinyl-1H-2-(methoxycarbonylamino)-benzimidazole (oxfendazole) through reaction of 5-phenylmercapto-1H-2-(methoxycarbonylamino)-benzimidazole with hydrogen peroxide in the presence of one or more aliphatic C1-C6-alcohols with addition of a strong, nonoxidizing mineral acid.