Patent ID: 9233955
Filing Date: 2016-01-12
CPC Classification: A61P,C07D

Claim Text:
1. A process for the preparation of azilsartan or its esters or salts thereof comprising reacting methyl 2-ethoxy[(2′-(hydroxyamidino)biphenyl-4-yl]methyl]-1H-benzimidazole-7-carboxylate of formula (3) with “carbonyl” source in presence of a suitable base to obtain methyl 1-[[2′-4,5-dihydro-5-oxo-:-4H-1,2,4-oxadiazol-3-yl) biphenyl-4-yl]methyl]-2-ethoxy-1H-benzimidazole-7-carboxylate of formula (4); wherein “carbonyl” source can be selected from the group consisting of N,N carbonyldiimidazole, dialkyl carbonate, phosgene equivalents viz phosgene, diphosgene and triphosgene, alkyl and aryl carbodiimides selected from the group comprising of N,N-diisopropylcarbodiimide, N,N-dicyclohexyl carbodiimide, ditolyl carbodiimide; and preparing azilsarstan or its esters or salts thereof.