Patent ID: 6140502
Filing Date: 2000-10-31
Classification: C07D

Abstract:
A process for the re-racemisation of a (-)-2-phenylmethyl-3,3-dimethyl-piperidin-4-on derivative wherein a (-)-2-phenylmethyl-3,3-dimethyl-piperidin-4-on derivative of the formula 8.sub.BwhereinR.sub.2 denotes hydrogen C.sub.1 -C.sub.6 -alkyl, halogen, C.sub.1 -C.sub.8 -alkoxy, a benzoyl group bound via an oxygen or an alkylcarboxyl group having a straight chained or branched C.sub.1 -C.sub.6 -lower alkyl group--wherein the alkyl group may optionally be substituted by one or more halogen atoms which may be identical or different;is heated to yield a racemic mixture of compounds of the formulae 8.sub.A and