Patent ID: 8907106
Filing Date: 2014-12-09
Classification: C07B

Abstract:
1. Process for the resolution of two enantiomers by auto-seeded preferential evaporative crystallization, which comprises the stages consisting in: 1) Preparing a suspension comprising a racemic mixture of enantiomers, an excess of the first of the enantiomers and at least one solvent, at a temperature T, so that the overall synthetic mixture E 2) Evaporating a portion of the solvent present in the suspension prepared in 1) until a overall synthetic mixture E 3) Harvesting the crystals of the first enantiomer by filtration; 4) Adding, to the mother liquor resulting from the preceding filtration, the racemic mixture in the form of crystals, and also solvent, so that the overall composition of the system is represented by the point E′ 5) Leaving the suspension stirring at the temperature T until the thermodynamic equilibrium is reached; 6) Evaporating substantially the same amount of solvent as during stage 2), so that the overall synthetic mixture reaches a point E′ 7) Harvesting the crystals of the second enantiomer by filtration; 8) Adding, to the mother liquor resulting from the preceding filtration, the racemic mixture in the form of crystals, and also solvent, so that the overall composition of the system is represented by the point E 9) Leaving the suspension stirring at the temperature T until the thermodynamic equilibrium is reached; 10) Repeating stages 2) to 9) in order to successively obtain one and then the other of the enantiomers.