Reaction Steps
To a stirred suspension of 3-(5-aminomethyl-2-methyl-4-oxo-4H-quinazolin-3-yl)-piperidine-2,6-dione hydrogen chloride (0.53 g, 1.6 mmol) and triethylamine (0.31 mL, 2.2 mmol) in THF (15 mL) at 5˜10° C., was added 3,4-dimethyl phenyl isocyanate (0.29 mL, 2.1 mmol). Then the mixture was stirred at room temperature overnight. The mixture was quenched with methanol (˜1 mL), and the solvent was evaporated. The residue was purified by flash column chromatography (Silica gel, methanol/methylene chloride 4%/96%) to give 1-(3,4-dimethyl-phenyl)-3-[3-(2,6-dioxo-piperidin-3-yl)-2-methyl-4-oxo-3,4-dihydro-quinazolin-5-ylmethyl]-urea as an off-white solid (520 mg, 73% yield); HPLC, Waters Symmetry C18, 5 μm, 3.9×150 mm, 1 mL/min, 240 nm, 10/90 CH3CN/0.1% H3PO4, grad. to 95/5 in 5 min, kept 5 min, 6.14 min (96.6%); mp, 241-243° C.; 1HNMR (DMSO-d6)2.11-2.21 (m, 7H, CHH, 2ArCH3), 2.59-2.94 (m, 6H, CHCH2, CH3), 4.71 (d, J=5 Hz, 2H, CH2NH), 5.27 (dd, J=6, 11 Hz, 1H, CH), 6.56 (t, J=5 Hz, 1H, CH2NH), 6.92-7.78 (m, 6H, Ar), 8.58 (s, 1H, NH), 11.05 (s, 1H, NH); 13C NMR (DMSO-d6) δ 18.58, 19.59, 20.70, 23.24, 30.62, 42.26, 56.52, 115.18, 117.76, 118.99, 125.54, 126.28, 128.50, 129.46, 134.01, 136.03, 138.15, 141.69, 148.27, 154.87, 155.11, 160.94, 169.47, 172.65. LCMS MH=448; Anal Calcd For C24H25N5O4+2.0H2O: C, 59.62; H, 6.05; N, 14.48. Found: C, 59.36; H, 5.95; N, 14.24.
