反应详情

To a suspension of crude 4-piperidin-1-yl-butyric acid ethyl ester from the previous step (about 25 mmol) in 15 mL of water, NaOH (1.4 g, 25 mmol) was added and the mixture was heated at reflux for 16 hours. The reaction was then allowed to cool down to room temperature, the solution was acidified at 0° C. with HCl 6N and concentrated under reduced pressure. The residue was treated with EtOH and the sodium chloride which precipitated was filtered off. Evaporation of the solvent under reduced pressure afforded 2.8 g of the title compound as a white solid in 58% overall yield of steps a) and b)

1. temperaturethe mixture was heated
2. temperatureat reflux for 16 hours
3. concentrationconcentrated under reduced pressure
4. additionThe residue was treated with EtOH
5. customthe sodium chloride which precipitated
6. filtrationwas filtered off
7. customEvaporation of the solvent under reduced pressure