PROCESS OF ENANTIOMERIC RESOLUTION OF D,L-(+)-THREO-METHYLPHENIDATE

摘要

A process for preparing the d-threo isomer of methylphenidate hydrochlori de which includes (i) resolving a racemic mixture of racemic threo-methylphe nidate hydrochloride with a less than stoichiometric amount of tertiary amin e base to obtain a methylphenidate - chiral acid salt, (ii) basifying the me thylphenidate - chiral acid salt to obtain methylphenidate free base, and (i ii) converting the methylphenidate free base into d-threo-methylphenidate hy drochloride