反应详情

Triphosgene (21.3 g, 72 mmol) was added in portions to a solution of (2S,5R)-ethyl 5-((benzyloxy)amino)piperidine-2-carboxylate (50 g, 0.18 mol) and DIPEA (128 mL, 0.72 mol) in DCM (2000 mL) at 0° C. After stiffing at 20° C. overnight, the reaction mixture was washed with H3PO4 (10%), sat. NaHCO3 and saturated NaCl. The combined organic layer was concentrated in vacuum and purified by silica gel column chromatography (3:1 petroleum ether/EtOAc) to afford (2S,5R)-ethyl 6-(benzyloxy)-7-oxo-1,6-diazabicyclo[3.2.1]octane-2-carboxylate (27.4 g, 50%) as a yellow solid.

1. washthe reaction mixture was washed with H3PO4 (10%), sat. NaHCO3 and saturated NaCl
2. concentrationThe combined organic layer was concentrated in vacuum
3. custompurified by silica gel column chromatography (3:1 petroleum ether/EtOAc)