反应详情

To a solution of ethyl 4-piperidone-3-carboxylate hydrochloride (5 g, 24.05 mmol) in THF (70 mL) and water (35 mL) at 0° C., was added triethylamine (8.7 mL, 62.5 mmol), followed by N-(benzyloxycarbonyloxy)succinimide (7.79 g, 31.27 mmol). The reaction mixture was stirred and allowed to warm to room temperature. After 3 hours the reaction mixture was diluted with water (50 mL) and ethyl acetate (100 mL) added. The aqueous phase was extracted into ethyl acetate (2×100 mL). The organic phases were combined, washed with brine (50 mL), dried (MgSO4), and the solvent removed in vacuo. The crude product was purified by column chromatography on silica gel (eluent, ethyl acetate:pentane=1:5) to give 4-hydroxy-5,6-dihydro-2H-pyridine-1,3-dicarboxylic acid 1-benzyl ester 3-ethyl ester as a colorless oil (7.26 g, 94%). MS (EI) 305 (M+).

1. additionadded
2. extractionThe aqueous phase was extracted into ethyl acetate (2×100 mL)
3. washwashed with brine (50 mL)
4. dry with materialdried (MgSO4)
5. customthe solvent removed in vacuo
6. customThe crude product was purified by column chromatography on silica gel (eluent, ethyl acetate:pentane=1:5)