Reaction Steps
3-Cyanophenyl isocyanate (0.4 g, 2.7 mmol) was added to a stirred suspension of 3-(4-aminomethyl-1-oxo-1,3-dihydro-isoindol-2-yl)-piperidine-2,6-dione hydrochloride (0.7 g, 2.1 mmol) and triethylamine (0.3 g, 2.9 mmol) in THF (30 mL) at 5-10° C. After stirring at 5° C. for 10 min, the mixture was warmed to room temperature and stirred overnight. The reaction was quenched with methanol (1 mL) and concentrated. The residue was stirred with 1N HCl (30 mL) for 30 minutes and filtered. The solid was slurried with hot methanol (15 mL) to give 1-(3-cyano-phenyl)-3-[2-(2,6-dioxo-piperidin-3-yl)-1-oxo-2,3-dihydro-1H-isoindol-4-ylmethyl]-urea (0.33 g, 38%) as a white solid: mp 330-333° C.; 1H NMR (DMSO-d6) δ 2.01-2.05 (m, 1H), 2.37-2.65 (m, 2H), 2.86-3.00 (m, 1H), 4.37-4.58 (m, 4H, 2CH2), 5.11-5.18 (dd, J=4.9 and 13.1 Hz, 1H, CH), 6.92 (t, J=5.5 Hz, 1H, NH), 7.32-7.65 (m, 6H, Ar), 7.93 (s, 1H, Ar), 9.00 (s, 1H, NH), 11.01 (s, 1H, NH); 13C NMR (DMSO-d6) δ 22.55, 31.17, 39.67, 46.18, 51.57, 111.41, 118.91, 120.24, 121.59, 122.36, 124.64, 128.30, 130.02, 130.35, 131.63, 135.27, 139.92, 141.21, 154.98, 168.05, 171.00, 172.82; Anal. calcd. for C22H19N5O4+0.1H2O: C, 63.03; H, 4.62; N, 16.71. Found: C, 62.69, H, 4.48; N, 16.41.
