Reaction Steps
A mixture of 2-quinoxalinecarboxylic acid (0.35 g, 2.0 mmol) and CDI (0.39 g, 2.4 mmol) in DMF (25 mL) was stirred at ambient temperature under nitrogen for 90 minutes. 4-Aminomethyl-2-(2,6-dioxopiperidin-3-yl)isoindole-1,3-dione hydrochloride (0.65 g, 2.0 mmol) and triethylamine (0.61 g, 6.0 mmol) were added, and the mixture was allowed to stir for 16 hours. The mixture was poured into water, resulting in precipitation of the product, which was filtered, washed with additional water (40 mL) and dried, providing 0.61 g, in 69% yield: mp>260° C.; 1H NMR (DMSO-d6) δ 2.07-2.12 (m, 1H), 2.56-2.65 (m, 2H), 2.85-2.98 (m, 1H), 5.05 (d, J=6.3 Hz, 2H), 5.19 (dd, J=12.6 Hz, d=5.4 Hz, 1H), 7.78-7.83 (m, 3H), 7.98-8.04 (m, 2H), 8.19-8.24 (m, 2H), 9.50 (s, 1H), 9.76 (t, J=6.3 Hz, 1H), 11.16 (s, 1H); 13C NMR (DMSO-d6) δ 22.0, 30.9, 38.4, 48.9, 121.9, 127.2, 129.1, 129.4, 131.3, 131.6, 132.0, 133.1, 134.8, 138.7, 139.8, 143.0, 143.8, 144.1, 163.7, 167.0, 167.6, 169.8, 172.8; Anal. calcd for C23H17N5O5.0.5H2O: C, 61.06; H, 4.01; N, 15.47. Found: C, 61.19; H, 3.95; N, 15.37.
