反应详情

4-Methyl-6,7-dimethoxyquinazoline (D-1) (3.43 g, 14.7 mMol), N-bromosuccinimide (NBS) (2.64 g, 14.7 mMol) and benzoyl peroxide (BPO) (500 mg) were heated under reflux in 200 mL of carbon tetrachloride with irradiation by a 200 W sun lamp for 5 h. The reaction mixture was cooled to room temperature, diluted with dichloromethane and extracted twice with water. The combined organic layers were dried over anhydrous sodium sulfate and concentrated under vacuum. Flash chromatography on silica gel, eluting with hexanes/ethyl acetate gave 4-bromomethyl-6,7-dimethoxyquinazoline (E-1) as a pinkish solid, 1.39 g; 1H NMR (CDCl3, 300 MHz) 9.07 (s, 1H), 7.34 (s, 1H), 7.30 (s, 1H), 4.85 (s, 2H), 4.06 (s, 6H) ppm; 13C NMR (CDCl3, 75 MHz) 161.22, 156.32, 153.45, 150.72, 149.22, 118.85, 107.47, 101.78, 56.84, 56.70, 30.13; MS (ES) 283/285 (M+H).

1. extractionextracted twice with water
2. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
3. concentrationconcentrated under vacuum
4. washFlash chromatography on silica gel, eluting with hexanes/ethyl acetate