| 摘要 |
The present invention provides a method for recycling 3-carbamoymethyl-5-methylhexanoic acid from a 3-carbamoymethyl-5-methylhexanoic acid chiral resolution mother liquor. The method comprises the following steps: (a) distilling the 3-carbamoymethyl-5-methylhexanoic acid chiral resolution mother liquor, adding aromatic hydrocarbon, performing heating for dissolution, and preserving heat with stirring; (b) after the heat preservation reaction in step (a) is completed, cooling the product solution to 30-60ºC, then adding dropwise alkali liquor, and performing heat preservation reaction; and (c) after the heat preservation reaction in step (b) is completed, cooling the product solution to 20-30ºC, performing demixing, adjusting the pH of a demixed water layer to 1 to 2, performing extraction by using an organic solvent, distilling an organic phase under a reduced pressure, and performing crystallization at 0±5ºC to obtain 3-carbamoymethyl-5-methylhexanoic acid. The method provided in the present invention is convenient to operate, and the recycled product is high in purity (≥99.8%) and is high in yield. |
