PREPARATION OF ESCITALOPRAM

摘要

A substantially pure (S)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)benzonitrile intermediate for preparing escitalopram is prepared by: a) combining racemic (±)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)benzonitrile with (−)-di-p-toluoyltartaric acid, in a solvent; b) separating a solid phase comprising a salt of (−)-di-p-toluyltartaric acid with (R)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)benzonitrile enantiomer, and a liquid phase comprising a salt of (−)-di-p-toluoyltartaric acid with (S)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxy-butyl]-3-(hydroxymethyl)benzonitrile enantiomer; c) reacting the liquid phase with a base and isolating enantiomerically enriched (S)-4-[4-(dimethylamino)-1-(4′-fluorophenyl)-1-hydroxybutyl]-3-(hydroxymethyl)benzonitrile enantiomer; d) combining enantiomerically enriched (S)-enantiomer obtained in c) with (+)-di-p-toluoyltartaric acid, in a solvent; and e) reacting a precipitate from d) with a base.