Patent ID: 7119197

Claim:
A method for the preparation of optically pure (S)-(+)-10,11-dihydro-10-hydroxy-5H-dibenz[b,f]azepine-5-carboxamide, the method comprising the steps of: (1) reacting racemic (±)-10,11-dihydro-10-hydroxy-5H-dibenz[b,f]azepine-5-carboxamide with (2R,3R)-di-O,O′-substituted-tartaric acid anhydride to give a separable mixture (1:1) of diastereoisomeric 10-O-di-O,O′-substituted-tartrate half-esters of (±)-10,11-dihydro-10-hydroxy-5H -dibenz[b,f]azepine-5-carboxamide; (2) precipitation of the less soluble diastereoisomeric 10-O-di-O,O′-substituted-tartrate half-ester formed in step (1) by addition of water and separation of the same by filtration; and (3) base-catalysed hydrolysis of the less soluble diastereoisomeric 10-O-di-O,O′-substituted-tartrate half-ester obtained in step (2) to give the optically pure (S)-(+)-10,11-dihydro-10-hydroxy-5H-dibenz[b,f]azepine-5-carboxamide, wherein the (2R,3R)-di-O,O′-substituted-tartaric acid anhydride has the formula: where each R is the same and is C 1 to C 6 alkyl, or each R is phenyl.