Sulfuric Acid → 1,3,4,5-Tetrahydro-2H-1-benzazepin-2-one

Participants

Reaction Steps

To an ice bath cooled solution of 3,4-dihydronaphthalen-1(2H)-one (20 mL, 150 mmol) in chloroform (300 mL) was added sodium azide (14.62 g, 225 mmol) and then concentrated sulfuric acid (80 mL, 1499 mmol) was added dropwise over 30 minutes, and the mixture was stirred at room temperature for 24 hours. The biphasic solution was poured into ice, and the product was extracted twice with ethyl acetate. The organic layer was washed with water, dried over Na2SO4 and concentrated to give the crude product which was purified by silica gel chromatography (Analogix IntelliFlash™ 280, SF 25-120) loading with dichloromethane and eluting with 30% ethyl acetate/hexanes to obtain the title compound. 1H NMR (500 MHz, DMSO-d6) δ ppm 9.50 (s, 1H), 7.28-7.14 (m, 2H), 7.07 (td, J=7.4, 1.2, 1H), 7.00-6.85 (m, 1H), 2.67 (t, J=6.9, 2H), 2.20-2.03 (m, 4H); MS (ESI−) m/z 160.1 (M−H)−.

Provenance & Evidence