反应详情

To a solution of compound tert-butyl piperazine-1-carboxylate (37.2 g, 200 mmol) in ClCH2CH2Cl (500 mL) was added cyclobutanone (21 g, 300 mmol) and NaBH(OAc)3 (84.8 g, 400 mmol). The reaction mixture was stirred at rt for 16 h, quenched with saturated aq. Na2CO3 (500 mL) and extracted with DCM (3×500 mL). The combined organic layers were washed with brine (50 mL), dried, filtered and concentrated under reduced pressure to afford the desired compound tert-butyl 4-cyclobutylpiperazine-1-carboxylate (48 g, 100%) [LCMS: Rt=1.67 min, m/z 241.2 (M+H)+].

1. customquenched with saturated aq. Na2CO3 (500 mL)
2. extractionextracted with DCM (3×500 mL)
3. washThe combined organic layers were washed with brine (50 mL)
4. customdried
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure