反应详情

2-Amino-4,5-dimethoxyacetophenone (5.0 g) and boron trifluoride etherate (1.5 mL) were heated in formamide (80 mL) at 140° C. for 18 h. The reaction mixture was cooled to room temperature and extracted three times with benzene. The combined organic layers were dried over anhydrous sodium sulfate and concentrated under vacuum. Flash chromatography on silical gel, eluting with a mixture of 98/2 dichloromethane/methanol gave 4-methyl-6,7-dimethoxyquinazoline (D-1) as a yellow solid, 3.43 g; 1H NMR (CDCl3, 300 MHz) 8.99 (s, 1H), 7.30 (s, 1H), 7.18 (s, 1H), 4.05 (s, 6H), 2.87 (s, 1H) ppm; MS (ES) 205 (M+H).

1. extractionextracted three times with benzene
2. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
3. concentrationconcentrated under vacuum
4. washFlash chromatography on silical gel, eluting with a mixture of 98/2 dichloromethane/methanol