Patent ID: 7928240
Filing Date: 2011-04-19
Classification: C07D

Abstract:
1. A process for preparing a sulfoxide of formula I or a salt thereof either as a single enantiomer or in an enantiomerically enriched form: Wherein R wherein R R R R which comprises: a) reacting a mixture of enantiomers of sulfoxide of formula II, differing in configuration at sulfur atom of sulfoxide or a salt thereof: wherein R, X and R 1 -R 4 are as defined for formula I; with a substantially enantiomerically pure compound of formula: wherein R* is a chiral moiety having at least one asymmetric center and at least one asymmetric center in the chiral moiety can have either R or S configuration; Z is and Y is a leaving group to provide diastereomeric compounds of formula IV: wherein R, X, R*, R 1 -R 4 and Z are as defined above; b) separating the diastereomers of formula IV; and c) deprotecting the separated diastereomers with an acid or base to provide a single enantiomer or enantiomerically enriched compound of formula I and optionally preparing the enantiomer formed as the salt.