Triethylamine → Benzyl 2-[4-(tert-butoxycarbonylamino)piperidin-1-yl]ethylcarbamate

Beteiligte Stoffe

Reaktionsschritte

Into a solution of 2-bromoethylamine hydrobromide (5.0 g) and potassium carbonate (5.06 g) in THF/water (20/5 ml) was added at 0° C. benzyl chloroformate (4.16 g), and the resulting mixture was stirred at room temperature for 16 hours. The reaction mixture was mixed with water and was extracted with ethyl acetate. The organic layer was washed with an aqueous saturated solution of sodium chloride and was dried with anhydrous magnesium sulfate. The resulting organic layer was evaporated under reduced pressure to obtain benzyl 2-bromoethylcarbamate (7.32 g). A solution of benzyl 2-bromoethylcarbamate (7.23 g), tert-butyl 4-piperidinyl-carbamate formic acid salt (4.63 g) and triethylamine (8 ml) in acetonitrile (30 ml) was heated at reflux for 24 hours. After the reaction mixture was concentrated under reduced pressure, water was added to the residue, and the resulting mixture was extracted with ethyl acetate. The organic layer was washed with an aqueous saturated solution of sodium chloride and was dried with magnesium sulfate. After concentration under reduced pressure, the residue was subjected to purification using column chromatography (ethyl acetate/hexane) to obtain benzyl 2-[4-(tert-butoxycarbonylamino)piperidin-1-yl]ethylcarbamate (5.5 g) as colorless crystals.

Herkunft & Nachweise