Reaktion #46853

Reaktionsgleichung

piperidin-4-yl-carbamic acid tert-butyl ester

MeOH

NaCNBH3

(1-ethoxy-cyclopropoxy)-trimethyl-silane

→

(1-cyclopropyl-piperidin-4-yl)-carbamic acid tert-butyl ester

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThe mixture was filtered over “Celite”
2. 2
   EinengenThe filtrate was concentrated under reduced pressure
3. 3
   Waschenwashed with 250 mL of a 1 M NaOH-solution
4. 4
   ExtraktionThe aqueous layer was extracted with 300 mL ethyl acetate
5. 5
   WaschenThe combined organic layers were washed with brine
6. 6
   Trocknendried over anhydrous MgSO4
7. 7
   Einengenconcentrated under vacuo

Vorschrift

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.

Quelle