Patent ID: 7501448
Filing Date: 2009-03-10
Classification: A61P,C07D

Abstract:
1. A process for preparing telmisartan of formula I: said process comprising the steps of (a) combining 1,7′-dimethyl-2′-propyl-1H-3′H-[2.5′]bibenzoimidazolyl of formula III: with a 4′-bromomethyl-biphenyl-2-carboxylic acid alkyl ester of formula IV: an inorganic base and a low boiling point organic solvent, to obtain a mixture; (b) heating the mixture obtained in step (a) to a temperature of about 55° C. to about 120° C.; (c) maintaining the mixture obtained in step (b) for about 1 hour to about 8 hours, to obtain telmisartan alkylester of formula II: wherein R is a straight or branched chain C (d) recovering the telmisartan alkylester of formula II; and (e) hydrolyzing the telmisartan alkylester of formula II under acidic or basic conditions to obtain telmisartan of formula I.