Methyl iodide → 2-Methyl-1,2,4,5-tetrahydro-benzo[c]azepin-3-one

Reaction equation

[H-].[Na+].[CH2:3]1[C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][C:8]=2[CH2:7][CH2:6][C:5](=[O:14])[NH:4]1.[CH3:15]I>C1COCC1>[CH3:15][N:4]1[C:5](=[O:14])[CH2:6][CH2:7][C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=2[CH2:3]1

Participants

Procedure

At 25° C., sodium hydride (150 mg, 6.3 mmol) was added to a solution of 1,2,4,5-tetrahydro-benzo[c]azepin-3-one (1 g, 6 mmol) in THF (50 mL). The suspension was stirred for 10 minutes and treated with methyl iodide (1 g, 7 mmol). The mixture was stirred for an additional 4 hours and then partitioned between ethyl acetate (100 ml) and water (50 ml). Washing once with brine (30 ml), drying over anhydrous magnesium sulfate and evaporation of solvent gave 2-methyl-1,2,4,5-tetrahydro-benzo[c]azepin-3-one (1 g, 5.7 mmol, 95%): 1H NMR (300 MHz, CDCl3) δ 7.2 (m, 5H), 4.52 (s, 2H), 3.18 (t, 2H), 3.09 (s, 3H), 3.00 (t, 2H).