反应详情

To a 1,2-dichloroethane suspension (177 ml) of 3-amino-5-chloropyridin-2-ol (8.85 g) and tert-butyl 4-oxopiperidine-1-carboxylate (24.4 g) was added sodium triacetoxyborohydride (26.0 g), followed by stirring under heating at reflux for 4 hours. Tert-butyl 4-oxopiperidine-1-carboxylate (12.4 g) and sodium triacetoxyborohydride (13.7 g) were further added, and stirred under heating at reflux for 2 hours. After the reaction solution was brought back to room temperature, water and dichloromethane were added, and the solution was separated. The organic layer was dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to afford tert-butyl 4-[(5-chloro-2-hydroxypiperidin-3-yl)amino]piperidine-1-carboxylate (12.7 g).

1. temperatureunder heating
2. temperatureat reflux for 4 hours
3. stirringstirred
4. temperatureunder heating
5. temperatureat reflux for 2 hours
6. customwas brought back to room temperature
7. customthe solution was separated
8. dry with materialThe organic layer was dried over anhydrous sodium sulfate
9. concentrationconcentrated under reduced pressure
10. customThe residue was purified by silica gel column chromatography