Benzyl Bromide → 1-Benzylazepan-2-one

Participants

Reaction Steps

To a stirring 0° C. suspension of NaH (18.3 g, 763 mmol) in THF (195 mL) was added by addition funnel azepan-2-one (75.0 g, 667 mmol) in THF. An additional 2 L of solvent was added as the reaction progressed in order to maintain agitation of the very viscous reaction suspension. Following addition, the reaction was allowed to warm to room temperature, and when the evolution of H2 ceased after stirring overnight, benzyl bromide was added dropwise by addition funnel and the reaction was stirred overnight. The crude product was filtered through Celite and concentrated in vacuo. Recrystallization from hexanes and ethyl acetate provided pure 1-benzyl-azepan-2-one (142) as a white fluffy solid. 1H NMR (CDCl3) 7.38–7.24 (5H, m), 4.61 (2H, s), 3.33–3.29 (2H, m), 2.65–2.61 (2H, m), 1.77–1.66 (4H, m), 1.56–1.46 (2H, m) ppm. 13C NMR (CDCl3, 75 MHz) 176.13, 138.06, 128.67, 128.31, 127.43, 51.20, 49.04, 37.33, 30.12, 28.26, 23.58 ppm.

Provenance & Evidence