Reaction Steps
A mixture of 4-aminomethyl-2-(2,6-dioxopiperidin-3-yl)isoindole-1,3-dione hydrochloride (0.63 g, 1.9 mmol), 2-pyrazinecarbonylchloride (0.25 g, 1.9 mmol) and triethylamine (0.61 g, 6.0 mmol) in THF (30 mL) was stirred at ambient temperature under nitrogen for 18 hours. The mixture was evaporated, and the residue was chromatographed using a methylene chloride-methanol gradient, eluting the product with 95:5 methylene chloride-methanol. This material dissolved in 4 mL acetonitrile, and this solution was poured into 50 mL of water, resulting in precipitation of the product, which was filtered, washed with additional water (20 mL), and dried, providing 0.46 g (61% yield): mp>260° C.; 1H NMR (DMSO-d6) δ 2.06-2.10 (m, 1H), 2.54-2.65 (m, 2H), 2.84-2.91 (m, 1H), 4.97 (d, J=6.3 Hz, 2H), 5.18 (dd, J=12.0 Hz, d=5.4 Hz, 1H), 7.69-7.83 (m, 3H), 8.29 (t, J=1.9 Hz, 1H), 8.91 (d, J=2.5 Hz, 1H), 9.21 (d, J=1.4 Hz, 1H), 9.61 (t, J=6.3 Hz, 1H), 11.15 (s, 1H); 13C NMR (DMSO-d6) δ 22.0, 30.9, 38.3, 48.9, 121.9, 127.2, 131.2, 131.6, 133.0, 134.7, 143.5, 143.6, 144.5, 147.7, 163.4, 167.0, 167.6, 169.8, 172.8; Anal. calcd for C19H15N5O5.0.5H2O: C, 56.71; H, 4.01; N, 17.41. Found: C, 56.64; H, 3.75; N, 17.28.
