反应详情

2-(4-Methoxy-phenyl)-6,7-dihydro-5H-quinazolin-8-one (300 mg; 1.2 mmol) in 48% HBr (30 ml) is treated drop-wise with Br2 (189 mg; 1.2 mmol) dissolved in 48% HBr (0.8 ml). The reaction mixture is heated to 350 C for 10 minutes, poured on NaHCO3/water (20 g/100 ml) and extracted with TBME three times. The organic phases are combined, dried over Na2SO4 and evaporated to dryness, yielding the desired product as brown-yellow crystals. 1H-NMR (400 MHz; DMSO-d6): 9.08 (s, 1H); 8.33 (d, 2H); 7.10 (d, 2H); 5.22 (m, 1H); 3.84 (s, 3H); 3.07 (m, 2H); 2.73 (m, 1H); 2.45 (m, 1H). MS (m/z) ES+: 335, 333 (MH+); 255 (80).

1. temperatureThe reaction mixture is heated to 350 C for 10 minutes
2. additionpoured on NaHCO3/water (20 g/100 ml)
3. extractionextracted with TBME three times
4. dry with materialdried over Na2SO4
5. customevaporated to dryness