反应详情

To a solution of 7-methoxycarbonyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine [prepared in Preparation 4(1)] (1.0 g) in dimethylformamide (80 ml) were added 60% sodium hydride (in oil) (0.25 g) and ethyl iodide (1.0 g) and the mixture was stirred at room temperature for a day. Water was added to the reaction solution and extraction with ethyl acetate was conducted. The solvent was distilled off under reduced pressure and the resulting residue was recrystallized from ethyl acetate/hexane to give 4-ethyl-7-methoxycarbonyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine (0.3 g).

1. distillationThe solvent was distilled off under reduced pressure
2. customthe resulting residue was recrystallized from ethyl acetate/hexane