17775-01-8

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17775-01-8

B. Synthesis of 2,3,4,5-tetrahydrobenzo[f][1,4]oxazepines. Lithium aluminum hydride (0.85 g, 22 mmol) was added batchwise to a solution of 3,4-dihydro-2H-benzo[f][1,4]oxazepin-5-one (1.22 g, 7.48 mmol) in tetrahydrofuran (THF, 20 mL) at 0 °C. The reaction mixture was heated to reflux for 24 h and subsequently cooled to room temperature. Water (0.85 mL), 15% aqueous sodium hydroxide solution (0.85 mL) and water (2.55 mL) were added sequentially and slowly dropwise with continuous stirring. The insoluble salt was removed by filtration and the filtrate was concentrated to give the target product 2,3,4,5-tetrahydrobenzo[f][1,4]oxazepine (0.80 g, 72% yield). Thin layer chromatography (TLC) analysis (silica gel plate, unfolding agent: ethyl acetate) showed an Rf value of 0.14. Nuclear magnetic resonance hydrogen spectroscopy (1H NMR, 500 MHz, CDCl3) data: δ 7.19-7.12 (m, 2H), 7.03-6.97 (m, 2H), 4.04 (t, J = 4.5 Hz, 2H), 3.96 (s, 2H). 3.23 (t, J = 4.5 Hz, 2H), (one hydrogen signal not observed).