反应详情

TFA (600 mL) was added to a solution of (2S,5R)-1-tert-butyl 2-ethyl 5-((benzyloxy)amino)piperidine-1,2-dicarboxylate (263 g, 0.7 mol) in DCM (600 mL) at 20° C. The mixture was stirred at rt overnight and then concentrated under reduced pressure. The crude product was adjusted to pH 10 with sat. NaHCO3 solution then extracted with DCM (3×). The combined organic layer was concentrated under reduced pressure and purified by silica gel column chromatography (20:1 DCM/MeOH) to afford (2S,5R)-ethyl 5-((benzyloxy)amino)piperidine-2-carboxylate (184.9 g, 95%) as a yellow oil.

1. concentrationconcentrated under reduced pressure
2. extractionthen extracted with DCM (3×)
3. concentrationThe combined organic layer was concentrated under reduced pressure
4. custompurified by silica gel column chromatography (20:1 DCM/MeOH)