Patent ID: 8420822

Claim:
A process for resolution of substituted 2-(2-pyridinylmethylsulphinyl)-1H-benzimidazoles of formula (I) or a mixture thereof; Wherein R 1 -R 4 are the same or different and selected from hydrogen, alkyl, alkoxy, halogen, halo-alkoxy, alkylcarbonyl, alkoxycarbonyl, oxazolyl, trifluoroalkyl, or adjacent groups R 1 -R 4 form ring structures which may be further substituted; and R 5 , R 6 and R 7 are same or different and selected from hydrogen, alkyl, alkylthio, alkoxy optionally substituted by fluorine, alkoxyalkoxy, dialkylamino, piperidino, morpholino, halogen, phenylalkyl and phenylalkoxy; which comprises: a) reacting substituted 2-(2-pyridinylmethylsulphinyl)-1H-benzimidazoles of formula (I) or a mixtures thereof with a chiral 1,1′-binaphthyl-2-2′-diyl hydrogen phosphate (BNPPA) to obtain corresponding diastereomer complexes; b) isolating preferentially one diastereomer complex from the mixture of diastereomer complexes; and c) converting the isolated diastereomer complex to the corresponding enantiomer of the compound of formula (I).