(s)-4-hydroxy-2-oxo-1-pyrrolidineacetamide racemate crystal form ii and preparation method therefor

Abstract

An (S)-4-hydroxy-2-oxo-1-pyrrolidine acetamide racemate referred to as (S)-oxiracetam crystal form II has a diffraction peak at a diffraction angle 2θ of 10.669, 13.25, 13.847, 14.198, 16.729, 17.934, 18.746, 18.816, 20.273, 20.413, 21.431, 21.617, 21.663, 23.38, 24.324, 24.415, 26.069, 26.107, 27.901, 28.621, 28.925, 29.449, 29.484, 31.702, 36.516, 37.685, or 39.721 degrees. The purity of the (S)-oxiracetam crystal form II can be up to 98.5%, and the (S)-oxiracetam crystal form II has the advantages of simple preparation method, mild control condition, low production cost, and the produced oxiracetam hydrate crystal form II has a high purity (the oxiracetam hydrate crystal form having a purity of 8%˜98.5% can be prepared by a crude levo-oxiracetam having a purity of 92%, and thus having a good reproducibility in production.

Dependencies are inferred from the claim text.