反应详情

To a suspension of 2,4-dichloro-6,7-dimethoxyquinazoline (30.0 g, 0.12 mol) in acetonitrile (550 ml) at 0° C. was added nitronium tetrafluoroborate (25.9 g, 0.19 mol) portionwise over 15 min. The reaction was stirred for 0.75 h and then evaporated under reduced pressure. The resulting solid was suspended in a mixture of saturated aqueous sodium bicarbonate and EtOAc and the solid filtered, dissolved in CH2Cl2, dried over MgSO4 and evaporated to give the subtitle compound as a pale yellow solid (27 g). Further material was obtained by separating the organic layer of the filtrate, washing with H2O (1×), saturated brine (1×), drying over MgSO4 and filtering through a pad of silica. Subsequent evaporation under reduced pressure, trituration with EtOAc and filtration gave the subtitle compound as a pale yellow solid (3.9 g, overall yield 88%). Rf 0.24 (ether/hexane 1/1, v/v).

1. customevaporated under reduced pressure
2. additionThe resulting solid was suspended in a mixture of saturated aqueous sodium bicarbonate and EtOAc
3. filtrationthe solid filtered
4. dissolutiondissolved in CH2Cl2
5. dry with materialdried over MgSO4
6. customevaporated