反应详情

A solution of the compound (10.5 g) obtained in step 1 in 20% palladium hydroxide on carbon (50% wet, 2.63 g) in ethanol (250 mL) was stirred under a hydrogen atmosphere (1 atm) at room temperature for 14 hr. The catalyst was filtered off, and the filtrate was concentrated under reduced pressure. To a solution of the obtained residue in acetonitrile (50 mL) were added triethylamine (4.6 mL) and Boc2O (7.14 g), and the mixture was stirred at room temperature for 14 hr. The reaction mixture was poured into water, and the resultant product was extracted with ethyl acetate. The organic layer was washed with saturated aqueous sodium hydrogen carbonate solution and brine and dried, and the solvent was evaporated under reduced pressure. The obtained residue was separated and purified by silica gel column chromatography (solvent gradient; 10→20% ethyl acetate/hexane) to give 4-ethyl 1-tert-butyl (3R*,4S*)-3-phenylpiperidine-1,4-dicarboxylate (8.31 g, 76%) as a colorless oil.

1. filtrationThe catalyst was filtered off
2. concentrationthe filtrate was concentrated under reduced pressure
3. additionTo a solution of the obtained residue in acetonitrile (50 mL) were added triethylamine (4.6 mL) and Boc2O (7.14 g)
4. additionThe reaction mixture was poured into water
5. extractionthe resultant product was extracted with ethyl acetate
6. washThe organic layer was washed with saturated aqueous sodium hydrogen carbonate solution and brine
7. customdried
8. customthe solvent was evaporated under reduced pressure
9. customThe obtained residue was separated
10. custompurified by silica gel column chromatography (solvent gradient; 10→20% ethyl acetate/hexane)