methyl (S)-phenyl((R)-piperidin-2-yl)acetate → Dexmethylphenidate

Participants

Reaction Conditions

Reaction Steps

The chiral resolution generally proceeds by initially charging the racemic threo-methylphenidate, chiral acid and lower alkanol to a suitable reactor under agitation and ambient conditions. The base is then charged at a temperature ranging from about 20 to 30° C., and the resulting slurry is heated to an effective temperature, such as about 40 to 55° C. Process water is then charged and the mixture may be aged, such as aging at 40 to 45° C. for an effective amount of time, such as from about 15 minute to 1 hour. The heated resolution mixture is then cooled to a temperature and for a time effective to precipitate the d-threo-methylphenidate chiral acid salt. For example, the reaction can be cooled to about 0 to 25° C. over the course of approximately 1 to 3 hours and then aged at about 0 to 25° C. for about 1 to 3 hours. The precipitated d-threo methylphenidate/chiral acid salt is then isolated, such as by filtration.

Provenance & Evidence