|7164025||Manufacture of single isomer methylphenidate|
The present invention pertains to a process for obtaining a single enantiomer, d or l, of threo-methylphenidate, comprising resolution of a mixture of the enantiomers; racemisation of the unwanted enantiomer, to give a mixture of all four stereoisomers; and separati...
|6384227||Racemisation process for use in the manufacture of levobupivacaine and related piperidinecarboxanilide anaesthetic agents|
An optically-enrichedpiperidine-2-carboxanlidecompound, in which the piperidine is optionally N-alkylated, is racemized by heating the compound in an aqueous medium, provided that the medium includes an organic co-solvent if the compound is N-alkylated. T...
|5994548||Crystallisation of levibupivacaine and analogues thereof|
Levobupivacaine or an analogue thereof is prepared by reaction with a tartaric acid resolving agent in a solvent, in the presence of water and/or less 0.5 equivalents of the resolving agent....