Darwin Discovery Limited

Celltech Pharma Europe Limited

Marianne Langston

Hooshang Shahriari Zavareh

Benjamin Mark Skead

Ulrich Conrad Dyer

Martin Woods

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 separation of the erythro stereoisomers, to leave the same mixture of enantiomers for resolution.

Manufacture of single isomer methylphenidate

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. This process is particularly valuable, in conjunction with a resolution process, for the manufacture of levobupivacaine.

Racemisation process for use in the manufacture of levobupivacaine and related piperidinecarboxanilide anaesthetic agents

Crystallisation of levibupivacaine and analogues thereof

Growing community of inventors

Cambridge, United Kingdom

Marianne Langston