反应详情

To a solution of cis-(+/−)-1-(benzyloxycarbonyl)-5-(tert-butoxycarbonylamino) piperidine-3-carboxylic acid (1.2 g, 3.17 mmol), DPPA (Diphenylphosphoryl azide, 1.04 g, 3.81 mmol) and DIEA(1.1 mL, 6.35 mmol) in t-BuOH(10 mL) was heated to 90° C. over night. The solvent was removed under reduced pressure. To the crude was added EtOAc (300 mL), the organic layer was washed with saturated NaHCO3(150 mL) and brine, dried and filtered, and concentrated to give the crude. The crude material was further purified by silica gel chromatography to yielding cis-(+/−)-benzyl 3,5-bis(tert-butoxycarbonylamino)piperidine-1-carboxylate, (23%). LCMS (m/z): 350(minus one Boc(MH+); LC Rt=4.40 min.

1. customThe solvent was removed under reduced pressure
2. additionTo the crude was added EtOAc (300 mL)
3. washthe organic layer was washed with saturated NaHCO3(150 mL) and brine
4. customdried
5. filtrationfiltered
6. concentrationconcentrated
7. customto give the crude
8. customThe crude material was further purified by silica gel chromatography