反应详情

温度

60 °C

To a solution of 14.0 g (0.0699 mol) piperidin-4-yl-carbamic acid tert-butyl ester in 500 mL abs. MeOH 250 g of dried molecular sieves 3 Å were added. Under argon 39.9 mL (0.699 mol) acetic acid and 52.5 mL (0.262 mol) (1-ethoxy-cyclopropoxy)-trimethyl-silane were added. Finally 314.5 mL (0.3145 mol) of a 1 M NaCNBH3-solution in THF were added dropwise. After 20 min at room temperature the reaction mixture was stirred for 6 h at 60° C. The mixture was filtered over “Celite”. The filtrate was concentrated under reduced pressure. The resulting residue was taken up in 700 mL ethyl acetate and washed with 250 mL of a 1 M NaOH-solution. The aqueous layer was extracted with 300 mL ethyl acetate. The combined organic layers were washed with brine, dried over anhydrous MgSO4 and concentrated under vacuo to give crude (1-cyclopropyl-piperidin-4-yl)-carbamic acid tert-butyl ester as a colorless solid.

1. filtrationThe mixture was filtered over “Celite”
2. concentrationThe filtrate was concentrated under reduced pressure
3. washwashed with 250 mL of a 1 M NaOH-solution
4. extractionThe aqueous layer was extracted with 300 mL ethyl acetate
5. washThe combined organic layers were washed with brine
6. dry with materialdried over anhydrous MgSO4
7. concentrationconcentrated under vacuo