Reaction Steps
Teiethylamine (0.5 g, 5.2 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 m-toluoyl chloride (0.5 g, 2.9 mmol) in THF (30 mL) at 5-10° C. After stirring at 5° C. for 10 minutes, the mixture was stirred at room temperature overnight. The mixture was concentrated, and the residue was stirred with 1N HCl (20 mL). The mixture was filtered, and the solid was slurried with hot methanol (15 mL) to give N-[2-(2,6-dioxo-piperidin-3-yl)-1-oxo-2,3-dihydro-1H-isoindol-4-ylmethyl]-3-methyl-benzamide (0.7 g, 86%) as a white solid: mp 253-255° C.; 1H NMR (DMSO-d6) δ 2.01-2.05 (m, 1H), 2.35 (s, 3H, CH3), 2.35-2.65 (m, 2H), 2.86-3.00 (m, 1H), 4.40-4.61 (m, 4H, 2CH2), 5.12-5.19 (dd, J=5.0 and 13.2 Hz, 1H, CH), 7.34-7.70 (m, 7H, Ar), 9.05 (t, J=5.6 Hz, 1H, NH), 11.03 (s, 1H, NH); 13C NMR (DMSO-d6) δ 20.90, 22.59, 31.17, 46.28, 51.58, 121.62, 124.36, 127.76, 128.20, 128.30, 130.66, 131.60, 131.86, 134.07, 134.75, 137.59, 140.11, 166.45, 168.06, 170.99, 172.82; Anal. calcd. for C22H21N3O4: C, 67.51; H, 5.41; N, 10.74. Found: C, 67.52; H, 5.35; N, 10.71.