Patent ID: 8080670
Filing Date: 2011-12-20
Classification: C07D

Abstract:
1. A process for the preparation of 2-butyl-3-[[2′-(1H-tetrazol-5-yl)[1,1′-biphenyl]-4-yl]-1,3-diazaspiro[4,4]non-1-en-4-one (Irbesartan), which comprises: a) reacting 2-n-butyl-3-[(2′-cyanobiphenyl-4-yl)methyl]-1,3-diazaspiro-[4,4]-non-1-en-4-one with sodium azide and piperazine or its acid salt in a suitable organic solvent and obtaining the resulting 2-butyl-3-[[2′-(1H-tetrazol-5-yl)[1,1′-biphenyl]-4-yl]-1,3-diazaspiro[4,4]non-1-en-4-one as an alkaline salt in aqueous solution; b) neutralizing the alkaline salt solution of 2-butyl-3-[[2′-(1H-tetrazol-5-yl)(1,1′-biphenyl]-4-yl]-1,3-diazaspiro[4,4]non-1-en-4-one with an acid and isolating the precipitated irbesartan.