An improved synthesis of 2-mercapto-5-difluoromethoxy-1Hbenzimidazole: An important medicinal intermediate

Jabali J. Vora* Keyur P. Trive

Abstract

An improved, convergent and industrially useful process suitable for large-scale production of 2- mercapto-5-difluoromethoxy-1H-benzimidazole, required for synthesis of pantoprazole, has been described. Reaction of 4-hydroxy acetanilide with difluoromethylenechloride gave N-[4- (difluoromethoxy)phenyl]acetamide 2, which on further processes like nitration followed by hydrolysis, reduction and cyclization gave title compound 6. Structure of the synthesized compound was established on the basis of spectral analyses like IR, NMR and MASS.