反应详情

Under a nitrogen atmosphere, to a solution of 1.5 g of tert-butyl 4-[3-(pyridin-3-yl)propanoyl]piperazine-1-carboxylate in 25 mL of tetrahydrofuran was added 7 mL of a 1 M borane/tetrahydrofuran solution under ice-cooling. The mixture was heated to reflux for 6 hours, and then cooled to room temperature, and 10 mL of methanol was added thereto, followed by further heating to reflux for 16 hours. After cooling to room temperature, the mixture was concentrated under reduced pressure, and a mixture of a saturated aqueous sodium hydrogen carbonate solution and ethyl acetate was added thereto. The aqueous layer was separated, and then the organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography (chloroform/methanol) to obtain 1.43 g of tert-butyl 4-[3-(pyridin-3-yl)propyl]piperazine-1-carboxylate.

1. temperaturecooling
2. temperatureThe mixture was heated
3. temperatureto reflux for 6 hours
4. temperatureby further heating
5. temperatureto reflux for 16 hours
6. temperatureAfter cooling to room temperature
7. concentrationthe mixture was concentrated under reduced pressure
8. additiona mixture of a saturated aqueous sodium hydrogen carbonate solution and ethyl acetate
9. additionwas added
10. customThe aqueous layer was separated
11. washthe organic layer was washed with saturated brine
12. dry with materialdried over anhydrous magnesium sulfate
13. customThe solvent was evaporated under reduced pressure
14. customthe residue was purified by silica gel column chromatography (chloroform/methanol)