| 摘要 |
A crystal form II of (S)-4-hydroxy-2-oxo-1-pyrrolidine acetamide (referred to as a crystal form II of (S)-oxiracetam) has diffraction peaks appearing at the following 2¸ diffraction angles: 0.669, 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 and39.721. The crystal form II of (S)-oxiracetam in the present invention has a purity which can reach 98.5%. The preparation method of the crystal form II of (S)-oxiracetam is simple, with mild control conditions and low cost, through which a crystal form of (S)-oxiracetam hydrate with a purity of 98%-98.5% can be prepared from crude (S)-oxiracetam with a purity of 92% and the crystal form II of (S)-oxiracetam hydrate can be obtained in good reproducibility. |
