| 摘要 |
<p>The invention relates to an S-zopiclone-L-tartrate compound, to a process, which comprises reacting a mixture of R- and S-zopiclone and/or a salt thereof with L-tartaric acid in a solvent to form a solution containing zopiclone ions and L-tartaric acid ions, to a process for increasing the enantiomeric purity of S-zopiclone, which comprises: (a) selectively precipitating from a solution, which contains zopiclone and tartaric acid as solutes and acetonitrile as a solvent, an S-zopiclone-L-tartrate acetonitrile solvate; and (b) treating said S-zopiclone-L-tartrate acetonitrile solvate with a base to form enriched S-zopiclone and to the use of L-tartaric acid in the making of enriched S-zopiclone and/or its L-tartrate compound.</p> |
