Patent ID: 6794542
Filing Date: 2004-09-21
Classification: C07B,C07C

Abstract:
Process for the preparation of a diastereomerically enriched compound having formula (1) where R1 is a substituted or unsubstituted phenyl group, R2, R3 and R4 each differ from one another, each R2 and R3 is H, a substituted or unsubstituted (cyclo)alkyl group, alkenyl group, aryl group, cyclic or acyclic heteroalkyl group or heteroaryl group with one or more N, O or S atoms, or is (CH2)nâ€”COR6, where n=0, 1, 2 . . . 6 and R6=OH, a substituted or unsubstituted alkyl group, aryl group, alkoxy group or amino group, R4=CN, H or a substituted or unsubstituted allyl group, and R5 is H or alkyl with 1-6 C atoms, which process comprises reacting a compound of formula (2) where R1 and R5 have the aforementioned meanings with a compound having formula (3) R2â€”C(O)â€”R3â€ƒâ€ƒ(3) where R2 and R3 have the aforementioned meanings, to obtain the corresponding Schiff base, and treating the Schiff base with a cyanide source, a reducing agent or an allyl organometallic compound to convert said Schiff base into the diastereomerically enriched compound of formula (1).