Reaction Steps
A solution of 2-amino-N-(2,6-dioxo-piperidin-3-yl)-5-bromo-benzamide (0.51 g, 1.5 mmol) and trimethyl orthoformate (2 mL) and p-toluene sulfonic acid (150 mg) in acetonitrile (10 mL) was heated to reflux for 12 hours. To the mixture, was added water (70 mL), and stirred at room temperature for 2 hours. The suspension was filtered and washed with ethyl acetate (10 mL). The solid in NMP (3 mL) was heated at 80° C. To the solution, was added water (1.5 mL), and the mixture was allowed to cool to room temperature. The suspension was filtered and washed with NMP (1 mL) and ethyl acetate (10 mL) to give 3-(6-bromo-4-oxo-4H-quinazolin-3-yl)-piperidine-2,6-dione as a white solid (350 mg, 68% yield): HPLC: Waters Symmetry C18, 5 μm, 3.9×150 mm, 1 mL/min, 240 nm, 30/70 CH3CN/0.1% H3PO4, 4.18 min (99.9%); mp: 312-314° C.; 1H NMR (DMSO-d6) δ 2.14-2.21 (m, 1H, C W), 2.60-2.74 (m, 2H, 2CHH), 2.83-2.93 (m, 1H, CHH), 5.51 (brs, 1H, NCH), 7.68 (d, J=9 Hz, 1H, Ar), 8.03 (dd, J=2, 9 Hz, 1H, Ar), 8.24 (d, J=2 Hz, 1H, Ar), 8.42 (s, 1H, CH), 11.19 (s, 1H, NH); 13C NMR (DMSO-d6) δ 22.45, 30.93, 55.49, 119.83, 122.96, 128.23, 129.65, 137.61, 146.52, 147.94, 158.66, 169.75, 172.46: LCMS: MH=336, 338; Anal Calcd for C13H11N3O3Br+0.3H2O: C, 45.72; H, 3.13; N, 12.30; Br, 23.39. Found: C, 45.46; H, 2.75; N, 12.15; Br, 22.81.
