反应详情

To propylamine (75 μL, 1.09 mmol) and sodium acetate (92 mg, 1.12 mmol) in methanol (15 mL) was added bromomaleimide (200 mg, 1.12 mmol) dropwise in methanol (15 mL). After 10 minutes, solvent was removed in vacuo and purification by flash chromatography (10% ethyl acetate in petroleum ether) afforded the desired compound as a bright yellow waxy solid (82 mg, 0.53 mmol) in 49% yield. δH (500 MHz, CDCl3) 7.36 (s, 1H, NH), 5.45 (s, 1H, NH), 4.80 (d, 1H, J=1.3, H-5), 3.14 (dt, 2H, J=6.2 and 7.2, H2-3), 1.71-1.63 (m, 2H, H2-2), 0.99 (t, 3H, J=7.4, H3-1); δc (125 MHz, CDCl3) 172.31 (C═O), 167.73 (C═O), 149.83 (C4), 85.29 (C5), 46.16 (C3), 21.91 (C2), 11.42 (C1); IR (solid, cm−1) 3190 (m), 2962 (m), 1693 (m), 1627 (s); MS (EI) m/z (relative intensity): 154 (M+, 60), 125 (98), 84 (100); Exact Mass Calcd for [C7H10N2O2]+ requires m/z 154.0737 Found 154.0734 (EI); UV (Acetonitrile) ε240=7400 and ε348=5700 cm−1M−1 d3.

1. customsolvent was removed in vacuo and purification by flash chromatography (10% ethyl acetate in petroleum ether)