Hydrazine → 1H-1-Benzazepine

Participants

Reaction Steps

To a solution of the 8-(3-chloropyridazin-3-yl)benzazepine (0.77 g, 2.0 mmol) from step L above in ethanol (50 mL) were added hydrazine (1.0 mL, 20 mmol) and palladium on carbon (0.11 g). The reaction solution was heated under reflux for 16 h, and then it was cooled to room temperature, filtered through a plug of Celite and concentrated under reduced pressure. The crude product was purified by flash column chromatography (dichloromethane to 90:9:1 dichloromethane/methanol/concentrated ammonium hydroxide) to give the racemic benzazepine (0.20 g, 28%) as a yellow foam: 1H NMR (CDCl3, 500 MHz) δ 9.15 (dd, J=4.5, 1.5 Hz, 1H), 8.00 (d, J=2.0 Hz, 1H), 7.84 (dd, J=8.5, 1.5 Hz, 1H), 7.80 (d, J=8.0 Hz, 1H), 7.53 (dd, J=8.5, 5.0 Hz, 1H), 6.92-6.80 (br, 1H), 6.77-6.70 (br, 3H), 4.38 (d, J=8.5 Hz, 1H), 3.98 (d, J=13.0 Hz, 1H), 3.85 (d, J=14.0 Hz, 1H), 3.14-3.08 (m, 1H), 3.01-2.96 (m, 1H), 2.38 (s, 3H), 2.87-2.14 (m, 2H).

Provenance & Evidence