反应详情

To a solution (700 ml) of 1-tert-butyl 3-methyl(3R,5S)-5-{[(benzyloxy)carbonyl]amino}piperidine-1,3-dicarboxylate (115 g) in methanol was added 1M aqueous sodium hydroxide solution (350 ml) under ice-cooling, and the mixture was stirred at room temperature for 12 hr. The reaction mixture was concentrated under reduced pressure to about ⅓ volume, and the residual aqueous solution was washed with ethyl acetate-hexane (1:1, 600 ml). The aqueous layer was neutralized with 1M hydrochloric acid and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure to give the object product (98.5 g).

1. temperaturecooling
2. concentrationThe reaction mixture was concentrated under reduced pressure to about ⅓ volume
3. washthe residual aqueous solution was washed with ethyl acetate-hexane (1:1, 600 ml)
4. extractionthe mixture was extracted with ethyl acetate
5. washThe extract was washed with saturated brine
6. dry with materialdried over anhydrous magnesium sulfate
7. customThe solvent was evaporated under reduced pressure