反应详情

Stir a solution of methyl 2,2-dimethyl-3-oxo-propanoate (30.88 g, 237.31 mmoles) and tert-butyl piperazine-1-carboxylate (34.00 g, 182.55 mmoles) in DCM (500 mL) at room temperature for 20 minutes. Add acetic acid (2 equiv); 20.92 mL, 365.09 mmoles) followed by sodium triacetoxyborohydride (1.4 equiv; 54.17 g, 255.56 mmoles) over 0.5 h and stir the resulting mixture stirred at room temperature overnight. Carefully quench with water (250 mL) and transfer the mixture to a separating funnel with DCM (300 mL). Wash the resulting organic layer with brine. Dry over MgSO4, filter and evaporate to give tert-butyl 4-(3-methoxy-2,2-dimethyl-3-oxopropyl)piperazine-1-carboxylate. (58 g, 100%). MS (m/z): 301.2 (M+1).

1. stirringstirred at room temperature overnight
2. customCarefully quench with water (250 mL) and transfer the mixture to a separating funnel with DCM (300 mL)
3. washWash the resulting organic layer with brine
4. dry with materialDry over MgSO4
5. filtrationfilter
6. customevaporate