反应详情

Ethyl 1-(2,2,2-trichloroethoxycarbonyl)piperidine-4-carboxylate (158 g, 0.48 mol) was dissolved in a 2 N potassium hydroxide-ethanol solution (500 mL) and water (500 mL), followed by heating under reflux for about 1 hour. After cooling, to the reaction mixture was added water (300 mL), followed by extraction with ethyl acetate (300 mL×3). The aqueous layer was added a 10% aqueous citric acid solution, followed by extraction with ethyl acetate (500 mL×3), and the acidic fraction extracted was washed with saturated brine (300 mL). The resultant was dried over anhydrous sodium sulfate and then filtered, and the solvent was evaporated. The residue was washed with hexane to obtain 62.9 g of 1-(2,2,2-trichloroethoxycarbonyl)piperidine-4-carboxylic acid as a colorless crystal (yield 43%).

1. temperatureby heating
2. temperatureunder reflux for about 1 hour
3. temperatureAfter cooling, to the reaction mixture
4. extractionfollowed by extraction with ethyl acetate (300 mL×3)
5. additionThe aqueous layer was added a 10% aqueous citric acid solution
6. extractionfollowed by extraction with ethyl acetate (500 mL×3)
7. extractionthe acidic fraction extracted
8. washwas washed with saturated brine (300 mL)
9. dry with materialThe resultant was dried over anhydrous sodium sulfate
10. filtrationfiltered
11. customthe solvent was evaporated
12. washThe residue was washed with hexane