| 摘要 |
The present invention provides methods for preparing eszopiclone Form A, substantially chemically pure eszopiclone, or eszopiclone with low level(s) of residual solvent(s). The present invention also provides eszopiclone with low level(s) of residual solvent(s). The present invention also provides a process for optical enrichment of eszopiclone free base. For instance, one of the embodiments of the invention is directed to a method of preparing eszopiclone Form A, wherein the method comprises crystallizing eszopiclone free base from a solvent selected from the group consisting of isopropanol (IPA), methyl isobutyl ketone (MIBK), acetone, n-butanol, i-butanolisobutanol, 2-butanol, tetrahydrofuran (THF), dimethyl carbonate, methanol, ethanol, ethyl lactate, dimethylformamide (DMF), carbon tetrachloride, toluene, iso-butyl acetate and mixtures thereof.
|
