Patent ID: 6500963
Filing Date: 2002-12-31
Classification: C07B,C07D

Abstract:
A process for preparing a compound of formula 1optionally in the form of the tautomers thereof, whereinR1 and R2 independently of one another denote hydrogen or a group selected from C1-C4-alkyl, C3-C8-cycloalkyl, C6-C10-aryl and â€”C1-C4-alkylene-C6-C10-aryl, which may optionally be mono-, di- or trisubstituted by one or more groups selected from hydroxy, halogen, C1-C4-alkoxy and CF3, with the proviso that R1 and R2 cannot simultaneously have the same meaning, comprising: wherein a first step reacting a compound of formula 1-rac wherein R1 and R2 may have the meanings given in this claim, in a suitable solvent with one or more chiral aminoalcohol of formula 4whereinR3, R3â€², R4 and R4â€² which may be identical or different denote hydrogen or a group selected from C1-C4-alkyl, C3-C8-cycloalkyl, C6-C10-aryl and â€”C1-C4-alkylene-C6-C10-aryl, which may optionally be mono-, di- or trisubstituted by one or more groups selected from hydroxy, halogen, C1-C4-alkoxy, â€”Sâ€”C1-C4-alkyl, â€”SO2â€”C1-C4-alkyl, NO2 and CF3, with the proviso that if R3 and R3â€² have the same meaning, the groups R4 and R4â€² cannot have the same meaning, and with the proviso that if R4 and R4â€² have the same meaning, the groups R3 and R3â€² cannot have the same meaning, to form a salt of formula 1-salt wherein the groups R1, R2, R3, R3â€², R4 and R4â€² may have the meanings given hereinbefore, isolating the resulting crystalline compound 1-salt and subsequently isolating the target compound of the formula 1 therefrom.