Patent ID: 7411077
Filing Date: 2008-08-12
Classification: A61P,C07D

Abstract:
1. A process for the preparation of pure 1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile which comprises: (a) reacting 5-cyanophthalide with a 4-fluorophenylmagnesium halide; (b) treating the mixture thus obtained, containing the 3-hydroxymethyl-4-(4-fluorobenzoyl)benzonitrile and the 3-hydroxymethyl-4-[bis-(4-fluorophenyl)hydroxymethyl]benzonitrile with a reducing agent of ketones to alcohols; (c) submitting the mixture thus obtained, containing the 3-hydroxymethyl-4-[(4-fluorophenyl)hydroxymethyl]benzonitrile (C) and the 3-hydroxymethyl-4-[bis-(4-fluorophenyl)hydroxymethyl]benzonitrile to a cyclization reaction and isolating a mixture containing the 1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile (B) and the 1,1-bis(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile; and (d) treating the mixture thus obtained with a solvent capable of dissolving the 1,1-bis(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile and in which the 1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile (B) is insoluble and recovering the pure 1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofurancarbonitrile (B), wherein said solvent is isopropanol or methyl-t-butylether.