2-Aminophenol → methyl 2-(3-oxo-3,4-dihydro-2H-benzo[b][1,4]oxazin-2-yl)acetate

反応式

[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[OH:8].[C:9]1(=[O:15])[O:14][C:12](=[O:13])[CH:11]=[CH:10]1.[CH2:16](N(CC)CC)C>CO>[O:13]=[C:12]1[NH:1][C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=2[O:8][CH:11]1[CH2:10][C:9]([O:14][CH3:16])=[O:15]

参加物

実験手順

A mixture of 76.4 g of 2-aminophenol and 68.6 g of maleic anhydride in 1 liter of methanol was stirred at room temperature. After addition of 100 ml of triethylamine, the yellow mass dissolved and the solution was heated for 7 hours at reflux temperature. The methanol was then removed by evaporation under reduced pressure, and the remaining oil was added to ice-water. The mixture was extracted with dichloromethane, and the organic extract was dried over sodium sulfate and evaporated. The remaining residue was crystallized from ethanol. In this way, 47.5 g of methyl (3-oxo-2,3-dihydro-4H-1,4-benzoxazin-2-yl)acetate were obtained as white crystals having a melting point of 140° C.