ONE POT PROCESS FOR THE PREPARATION OF TELMISARTAN

摘要

A process for the preparation of bromine free telmisartan in one pot starting from 2-cyano-4'- methyl biphenyl, a compound of the Formula (1). The compound of the Formula (1) is chlorinated to give 4-chloromethyl-2' -cyanobiphenyl, the compound of the Formula (2). The reaction of the compound of the Formula (2), with 2-n-propyl-4-methyl-6-(1'- methylbenzimidazol-2'-yl) benzimidazole, a compound of the Formula (3) yields the compound 2-cyano-4'-[2"-n-propyl-4"-methyl-6"-(1'"-methylbenzimidazol-2"'- yl) benzimidazol-1"- ylmethyl] biphenyl, a compound of the Formula (4) which on hydrolysis of the cyano group yields telmisartan a compound of the Formula (5).