Patent ID: 8404853

Claim:
A process for preparation of an optically pure or optically enriched enantiomer of a sulphoxide compound of formula (I), said process consisting essentially of: a) providing a mixture of enantiomers of the sulphoxide compound of formula (I) as starting material, in an organic solvent; said enantiomers having R and S configurations at the sulfur atom of the sulphoxide group; b) treating the mixture of enantiomers, in the organic solvent, with (S)-(−)-BINOL; c) separating the adduct formed by the enantiomer and (S)-(−)-BINOL; d) if desired, repeating the operation of step (b); e) treating the adduct obtained in step (c) or (d) with metal base selected from Group I and Group II metal, thereby obtaining metal salt of one of the optical isomers of the sulphoxide compound in optically pure or optically enriched form; f) optionally, reacting the Group I metal salt of optically pure or optically enriched form the optical isomers of the sulphoxide compound obtained in step (e) to magnesium salt wherein the substituents in Formula (I) can be same or different selected from the following where R 1 is H or -Me; R 2 is H or —OMe; R 3 is H, -Me, or —OMe; R 4 is H or —OMe; R 5 is H, —OMe, or difluoromethoxy; R 6 is H, —O(CH 2 ) 3 OCH 3 , or —OCH2CF 3 ; and R 7 is H or CH 3 .