反应详情

To a suspension of pyrazolidin-3-one hydrogen chloride (5.00 g, 40.8 mmol) in DCM (120 mL) at 0° C. was added DIEA (2.5 eq), followed by CbzCl (1.15 eq). The resulting clear solution was warmed to it and stirred 3 h. The reaction mixture was washed with brine. The aqueous layer was separated and back-extracted with DCM (×2). The combined organic layers were dried over Na2SO4, and concentrated. The crude product was purified by a SiO2 column (0-100% EtOAc/Hexanes, Rf=0.35 in 100% EtOAc) to afford the desired product as a white solid (5.31 g).

1. temperatureThe resulting clear solution was warmed to it
2. washThe reaction mixture was washed with brine
3. customThe aqueous layer was separated
4. extractionback-extracted with DCM (×2)
5. dry with materialThe combined organic layers were dried over Na2SO4
6. concentrationconcentrated
7. customThe crude product was purified by a SiO2 column (0-100% EtOAc/Hexanes, Rf=0.35 in 100% EtOAc)