| abstract |
This patent discloses the method of separating 4- [4- (dimethylamino) -1- (4'-fluorophenyl) -1-hydroxybutyl] -3 (hydroxymethyl) benzonitrile as a mixture of racemic or non-racemic enantiomers into its isolated enantiomers, said method comprising: 4- [4- (dimethylamino) -1- (4'-fluorophenyl) -1-hydroxybutyl] -3- (hydroxymethyl) benzonitrile as salt with O, O'-di-p-toluyl-tartaric acid (+) - A fractional crystallization step of (S, S) or (-) - (R, R) -enantiomers in a solvent system comprising 1-propanol, ethanol or acetonitrile. |