Patent ID: 6673942
Filing Date: 2004-01-06
Classification: C07B,C07C,C07D

Abstract:
A process for the resolution of a DL-racemic mixture of a compound crystallizing in the form of a conglomerate from a supersaturated solution thereof, to recover both the D and the L enantiomers, which process comprises the steps of:a) effecting a preferential crystallization of one of said enantiomers from said supersaturated solution in the presence of an effective amount of a chiral enantioselective polymer which inhibits the crystallization of the opposite enantiomer; b) physically separating the thus crystallized said one enantiomer to obtain a mother liquor comprising an excess of said opposite enantiomer; c) adding to said mother liquor solid DL-racemic mixture of said compound in about twice the amount of said one enantiomer separated in step (b) and stirring the resulting suspension at a suitable temperature until substantially the entire suspended solid phase consists of said opposite enantiomer; and d) physically separating said solid opposite enantiomer, to obtain a solution having substantially the same composition as the initial solution used in step (a).