Process of enantiomeric resolution of...

Details Process of enantiomeric resolution of... Process of enantiomeric resolution of...

2011-03-01

2011-03-01

Chang, Celia (Department: 1625)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

Reexamination Certificate

active

07897777

ABSTRACT:
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.

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Prashad, Mahavir, “Approaches to the Preparation of Enantiomerically Pure (2R,2′R)-(+)-threo-Methylphenidate Hydrochloride” Review, (2001) pp. 379-392.
Prashad, Mahavir, “Resolution of (±)-threo-Methylphenidate with (R)-(−)-Binaphthyl-2,2″-Diyl Hydrogen Phosphaate: 0.5 M Equiv of Resolving Agent Is Better than 1M Equiv” Review, (2001) pp. 379-392.
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