反応手順
A mixture of 2-amino-5-bromobenzamide (0.100 g, 0.465 mmol), 4-(2-(tert-butyldimethylsilyloxy)ethoxy)-3-methylbenzaldehyde (0.143 g, 0.465 mmol), NaHSO3 (94%, 0.0515 g, 0.465 mmol), and p-TsOH.H2O (0.00885 g, 0.0465 mmol) in DMA (5.81 mL) was heated at reflux for 15 min, cooled to room temperature, the water (20 mL) was added. The precipitate was filtered, washed with water, triturated with acetone and filtered again. The crude solid was chromatographed on silica gel (CH2Cl2/CH3OH) to provide 6-bromo-2-(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)quinazolin-4(3H)-one (0.0395 g, 22%) and 6-bromo-2-(4-(2-(tert-butyldimethylsilyloxy)ethoxy)-3,5-dimethylphenyl)quinazolin-4(3H)-one (0.0227 g, 10%) as white solids. Selected data for 6-bromo-2-(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)quinazolin-4(3H)-one: 1H NMR (300 MHz, DMSO-d6) δ 12.48 (s, 1H), 8.20 (d, J=2.34 Hz, 1H), 8.01-7.80 (m, 3H), 7.66 (d, J=8.72 Hz, 1H), 4.90 (t, J=5.46 Hz, 1H), 3.85 (t, J=4.87 Hz, 2H), 3.73 (dd, J=10.06, 5.11 Hz, 2H), 2.32 (s, 6H); MS (APCI) m/z 345 [M+H]+. Selected data for 6-bromo-2-(4-(2-(tert-butyldimethylsilyloxy)ethoxy)-3,5-dimethylphenyl)quinazolin-4(3H)-one: 1H NMR (300 MHz, DMSO-d6) δ 12.49 (s, 1H), 8.20 (d, J=2.34 Hz, 1H), 7.95 (dd, J=8.71, 2.41 Hz, 1H), 7.90 (s, 2H), 7.67 (d, J=8.72 Hz, 1H), 3.90 (m, 4H), 2.32 (s, 6H), 0.90 (s, 9H), 0.09 (s, 6H); MS (APCI) m/z 503 [M+H]+.
