Reaktionsschritte
A solution of 2-amino-N-(2,6-dioxo-piperidin-3-yl)-4-methyl-benzamide (1.0 g, 3.8 mmol) and trimethyl orthoformate (10 mL) and p-toluene sulfonic acid (250 mg) was heated to 160° C. in a microwave oven for 30 minutes. The suspension was filtered and washed with methanol (20 mL), water (20 mL) and methanol (20 mL) to give 3-(7-methyl-4-oxo-4H-quinazolin-3-yl)-piperidine-2,6-dione as an off-white solid (880 mg, 85% yield): HPLC: Waters Symmetry C18, 5 μm, 3.9×150 mm, 1 mL/min, 240 nm, 20/80 CH3CN/0.1% H3PO4, 5.14 min (97.1%); mp: 313-315° C.; 1H NMR (DMSO-d6) δ 2.11-2.18 (m, 1H, CHH), 2.48 (s, 3H, CH3), 2.61-2.74 (m, 2H, 2CHH), 2.82-2.92 (m, 1H, CHH), 5.46 (br, 1H, NCH), 7.41 (dd, J=1, 8 Hz, 1H, Ar), 7.53 (s, 1H, Ar), 8.03 (d, J=8 Hz, 1H, Ar), 8.33 (s, 1H, CH), 11.15 (s, 1H, NH); 13C NMR (DMSO-d6) δ 21.23, 22.51, 30.91, 56.74, 118.95, 125.93, 126.74, 128.66, 145.27, 147.35, 147.59, 159.54, 169.88, 172.44; LCMS: MH=272; Anal Calcd for C14H13N3O3+0.1H2O: C, 61.58; H, 4.87; N, 15.39. Found: C, 61.41; H, 4.87; N, 15.15.
