反应详情

To ethyl 4-(2-pyrrolidon-1-yl)cyclohexylcarboxylate (5.0 g, mixture of cis and trans isomers, cis:trans=61:39) are added ethanol (25.0 mL, 5V/W) and sodium ethoxide (2.0 equiv. 0.0132 mol), and the mixture is stirred at room temperature for 20 hours. After adding water (5.0 mL, 1V/W), the reaction solution is stirred at room temperature for 2 hours, and evaporated to remove ethanol under reduced pressure. The residue is acidified by adding 2 N hydrochloric acid, and thereto is added an excessive amount of crystalline sodium chloride followed by extraction with methylene chloride. The extract is dried, and evaporated to remove the solvent under reduced pressure. The resulting crystals are collected with toluene to give 4-(2-pyrrolidon-1-yl)cyclohexylcarboxylic acid (2.9 g, trans:cis=88:12, yield 58%).

1. stirringthe reaction solution is stirred at room temperature for 2 hours
2. customevaporated
3. customto remove ethanol under reduced pressure
4. additionby adding 2 N hydrochloric acid
5. additionis added an excessive amount of crystalline sodium chloride
6. extractionfollowed by extraction with methylene chloride
7. customThe extract is dried
8. customevaporated
9. customto remove the solvent under reduced pressure
10. customThe resulting crystals are collected with toluene