反应详情

Pyridine (2 mL) was added to a solution of (2S,5R)-tert-butyl 5-(N-(benzyloxy)-2-nitrophenylsulfonamido)-2-carbamoylpiperidine-1-carboxylate (1.0 g, 1.87 mmol) in dry THF (40 mL). Then, Tf2O (1.0 mL) was slowly added over 5 minutes. The mixture was stiffed at 0° C. for 1 h and then EtOAc (30 mL) was added. The mixture was washed with saturated sodium chloride (4×), dried overNa2SO4, and concentrated. The residue was purified by silica gel column chromatography (gradient elution 0˜40% petroleum ether/EtOAc) to give (2S,5R)-tert-butyl 5-(N-(benzyloxy)-2-nitrophenylsulfonamido)-2-cyanopiperidine-1-carboxylate (0.76 g, 79%) as a yellow solid ESI-MS (EI+, m/z): 539.0 [M+Na]+.

1. washThe mixture was washed with saturated sodium chloride (4×)
2. customdried overNa2SO4, and
3. concentrationconcentrated
4. customThe residue was purified by silica gel column chromatography (gradient elution 0˜40% petroleum ether/EtOAc)