azepane-2,4-dione

165257-04-5

29520-88-5

Example 2A: Synthesis of benzyl-2,4-dione 4-Ethoxy-6,7-dihydro-1H-azepin-2(5H)-one (2.5 g, 16 mmol) was dissolved in acetone (70 mL) and 10% HCl aqueous solution (17 mL) was added. The reaction mixture was stirred at 25°C for 12 hours. After completion of the reaction, the acetone was removed under vacuum. The resulting mixture was extracted with dichloromethane (10 x 15 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered and concentrated in vacuum to give the crude product as a yellow solid. Purification by fast column chromatography (silica gel, 10% methanol/ethyl acetate) afforded azepane-2,4-dione (2.03 g, 100%) as a white solid. The product characterization data were as follows: 1H NMR (400 MHz, CDCl3) δ 7.55 (s, NH), 3.47 (s, 2H), 3.40 (m, ), 2.59 (t, J = 6.8 Hz, 2H), 1.96 (m, 2H). 13C NMR (100 MHz, CDCl3) δ 202.5, 169.5, 51.9, 43.2, 40.8, 27.6; IR (KBr) νm, 2.59 (t, J = 6.8 Hz, 2H), 1.96 (m, 2H). IR (KBr) νmax 3213, 3105, 2942, 1702, 1671, 1482, 1412, 1348 cm?1; HRMS (ESI) m/l; δ HRMS (ESI) m/z calculated C6H9NO2Na: 150.0525; measured: 150.0507.