[Synthesis]
A solution of potassium carbonate (2.94 g, 14.16 mmol) in DMF (10 mL) was slowly added dropwise at room temperature to a stirred solution of 3-oxa-9-azabicyclo[3.3.1]nonan-7-one hydrochloride (1.26 g, 7.08 mmol, CAS: 1126795-00-3, purchased from PharmaBlock (Nanjing) R&D Co. 14.16 mmol) in DMF (10 mL) solution at room temperature. Benzyl bromide (1.33 g, 7.78 mmol) was then added. The reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, the mixture was concentrated and the residue was partitioned between water (5 mL) and ethyl acetate (20 mL). The organic layer was separated, dried over anhydrous sodium sulfate, filtered and concentrated. Purification of the residue by column chromatography afforded the target compound 9-benzyl-3-oxa-9-azabicyclo[3.3.1]nonan-7-one (1.38 g, 84.2% yield). The structure of the product was confirmed by 1H NMR (CDCl3, 400 MHz) and LC/MS: 1H NMR (CDCl3, 400 MHz) δ 7.36 (m, 5H), 3.93 (s, 2H), 3.86 (d, J = 11.0 Hz, 2H), 3.73 (d, J = 10.8 Hz, 2H), 3.18 (d, J = 5.6 Hz, 2H), 2.76 (d, J = 5.6 Hz, 2H), 3.18 (d, J = 5.6 Hz, 2H). 2H), 2.76 (dd, J = 15.9, 5.6 Hz, 2H), 2.35 (d, J = 15.6 Hz, 2H); LC/MS: Calculated value 232 (MH+), Experimental value 232 (MH+). |