Patent ID: 7838683
Filing Date: 2010-11-23
Classification: C07D

Abstract:
1. A process for making irbesartan, comprising the steps of: (1) reacting a 2-butyl-1,3-diazaspiro[4.4]non-1-ene-4-one acid addition salt with a halobenzyl halide compound in a first two-phase solvent system comprising first and second solvents in the presence of a first phase transfer catalyst to obtain 2-butyl-3-halobenzyl-1,3-diazaspiro[4.4]non-1-ene-4-one; (2) reacting the 2-butyl-3-halobenzyl-1,3-diazaspiro[4.4]non-1-ene-4-one of step (1) with 2-(1-trityl-1H-tetrazol-5-yl)phenylboronic acid in a second two-phase solvent system in the presence of a second phase transfer catalyst; (3) dissolving the product of step (2) in acetone; (4) acidifying the solution; (5) neutralizing the solution and separating the trityl alcohol, whereby a second solution is obtained; (6) acidifying the second solution; (7) cooling the acidified second solution; and (8) recovering irbesartan.