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

摘要

A process for preparing the d-threo isomer of methylphenidate hydrochloride which includes (i) resolving a racemic mixture of racemic threo-methylphenidate hydrochloride with a less than stoichiometric amount of tertiary amine base to obtain a methylphenidate - chiral acid salt, (ii) basifying the methylphenidate - chiral acid salt to obtain methylphenidate free base, and (iii) converting the methylphenidate free base into d-threo-methylphenidate hydrochloride