Patent ID: 7902380

Claim:
A process for preparation of (S)-alpha-ethyl-2-oxo-1-pyrrolidineacetamide or (R)-alpha-ethyl-2-oxo-1-pyrrolidineacetamide from (RS)-alpha-ethyl-2-oxo-1-pyrrolidinacetic acid comprising: i) combining the (RS)-alpha-ethyl-2-oxo-1-pyrrolidinacetic acid with a chiral base selected from the group consisting of optically pure: (R)-alpha methylbenzylamine, (S)-alpha methylbenzylamine, (R)-dehydroabietylamine and (S)-dehydroabietylamine in a resolution solvent thereby forming a resolution mixture ii) crystallising from the resolution mixture a diastereomeric salt of the chiral base and (S)-alpha-ethyl-2-oxo-1-pyrrolidinacetic acid or the chiral base and (R)-alpha-ethyl-2-oxo-1-pyrrolidinacetic acid; iii) treating the diastereomeric salt with a first suitable acid or acidic ion-exchange resin thereby regenerating (S)-alpha-ethyl-2-oxo- 1-pyrrolidinacetic acid or (R)-alpha-ethyl-2-oxo-1-pyrrolidinacetic acid; iv) reacting, in the presence of a suitable base, a compound of formula RSO 2 X with (R)-alpha-ethyl-2-oxo-1-pyrrolidinacetic acid or (S)-alpha-ethyl-2-oxo-1-pyrrolidinacetic acid thereby forming a mixed anhydride; and vii) reacting the mixed anhydride with ammonia; wherein R is a C1 to C15 alkyl or aryl and X is a halogen.