US 2010/0137613 A1 · PROCESS FOR EPROSARTAN

Abstract

The present invention provides an improved and commercially viable process for preparation of eprosartan and its pharmaceutically acceptable acid addition salts thereof in high purity and in high yield. Thus, for example, methyl 4-[[2-butyl-5-formyl-1 H-imidazol-1-yl]methyl]benzoate is reacted with ethyl 2-carboxy-3-(2-thienyl)propionate in the presence of a base, such as piperidine or piperidinium propionate in propionic acid, in cyclohexane solvent to give ethyl (αE)-α-[(2-n-butyl-1-[(4-(methoxy-carbonyl) phenyl]methyl]-1 H-imidazol-5-yl]methylene-2-thiophene propionate substantially free of decarboxylate impurity namely, ethyl 3-(2-thienyl)propionate, which is then subjected to base hydrolysis followed by treatment with methanesulfonic acid to obtain eprosartan mesylate in high purity and in high yield.

Claims13

Dependent claims

A process for preparation of eprosartan of formula I:

or a pharmaceutically acceptable salt thereof;
which comprises:
to a) reacting methyl 4-[[2-butyl-5-formyl-1H-imidazol-1-yl]methyl]benzoate of formula II:
with ethyl 2-carboxy-3-(2-thienyl)propionate of formula III:
in the presence of a base in a solvent selected from cyclohexane and n-hexane to give diester intermediate of formula IV:
substantially free of decarboxylate impurity namely, ethyl 3-(2-thienyl)propionate;
and
b) hydrolyzing the compound of formula IV with a base such as sodium or potassium hydroxide to obtain pure eprosartan of formula I and optionally converting eprosartan formed into a pharmaceutically acceptable acid addition salts of eprosartan.

5 more elements

Dependencies are inferred from the claim text.

Process for eprosartan

Life of this patent

Process for eprosartan

Life of this patent

Abstract

Claims13