In general 5-substituted tetrazoles were prepared through the reactions of sodium azide with nitriles in an aromatic solvent in the presence of an amine salt. The present work describes process for the preparation of the 2-butyl-3-[[2’-(1H-tetrazol-5-yl) [1,1’-biphenyl]-4-yl]methyl]-1,3-diazaspiro[4.4]non-1-en-4-one [Irbesartan] by reaction of the corresponding 2-butyl-3-[(2’-cyanobiphenyl)-4-yl] methyl-1,3-diazaspiro[4.4]non-1-ene with an sodium azide and dimethylamine hydrochloride
