A Modification to the Synthesis of Telmisartan: An Antihypertensive Drug

Abstract

A highly efficient approach to the synthesis of Telmisartan is described. Directed ortho-metalation of 4,4-dimethyl-2-phenyl-4,5-dihydrooxazole provided the key organozinc intermediate for a palladium catalysed biaryl coupling with 3′-(4-bromobenzyl)-1,7′-dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazole which was obtained from alkylation of 1,7′-dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazole. This methodology overcomes many of the drawbacks associated with previously reported syntheses.