PROCESS FOR THE PREPARATION OF EPROSARTAN

摘要

Disclosed herein is an improved novel synthetic process for the preparation of Eprosartan, which comprises treating 2-n-butyl-4-formylimidazole of formula (II) with N-protecting group selected from the group consisting of C1-C4 alkyl ester derivative of methacrylic acid; C1-C4 alkyl ester derivative of crotonic acid; or CJ-C4 alkyl ester derivative of acrylic acid in the presence of a base selected from anion exchange resin or DBU and optionally in presence of a solvent, to get N-protected compound(III) in Stage-I. Stage-Il comprises reacting N-protected compound (HI) with 2-(2-thienyl methyl) propanedioic acid monoethyl ester to get compound (V). Stage-III comprises reacting compound (V) obtained from stage-Il with methyl-4-(bromomethyl) benzoate to get compound (VIl). Further, simultaneous hydrolysis of ester groups and removal of N-protecting group is accomplished using caustic soda solution, to yield Eprosartan of Formula (I) in Stage- IV. Finally, pharmaceutical acceptable salt of Eprosartan is prepared in Stage- V.