Hydrochloric Acid → 8-methoxy-2,3-dihydro-1H-3-benzazepin-2-one

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Reaction Steps

A solution of N-(2,2-dimethoxy-ethyl)-2-(3-methoxy-phenyl)-acetamide (53.6 g, 0.21 mol) in acetic acid (140 mL) and aqueous 37% HCl (100 mL) was stirred at room temperature overnight. The reaction mixture was diluted with a ice/water mixture with vigorous stirring to yield a precipitate. The precipitate was filtered, rinsed with water, and then dissolved in dichloromethane, dried (MgSO4), concentrated and dried in high vacuum to give 8-methoxy-1,3-dihydrobenzo[d]azepin-2-one (20.5 g, 51%) as a tan solid. 1H-NMR (CDCl3) δ 8.23 (br s, 1H), 7.15 (d, J=8.3 Hz, 1H), 6.86 (d, J=8.6 Hz, 1H), 6.79, (s, 1H), 6.33 (d, J=9.1 Hz, 1H), 6.16 (dd, J=4.8, 9.3 Hz, 1H), 3.83 (s, 3H), 3.48 (s, 2H); LC/MS (ESI+): 190.05 (M+H).

Provenance & Evidence