反应详情

A mixture of 7-fluoro-3,4-dihydro-1H-quinoxalin-2-one (4.00 g, 24.1 mmol, 1.0 eq), sodium hydroxide (1.93 g, 48.2 mmol, 2.0 eq) and of 3% hydrogen peroxide solution (50 mL) is refluxed for 2 hours, then it is acidified by slow addition of acetic acid. The resulting mixture is cooled to room temperature, the precipitated solid is collected by filtration, washed with ice-water, and dried under vacuum to give a crude that is purified by column chromatography (silica gel, eluent: dichloromethane:methanol, 50:1, v/v) to afford 7-fluoro-quinoxalin-2-ol as a yellow solid (2.60 g, 69% yield).

1. filtrationthe precipitated solid is collected by filtration
2. washwashed with ice-water
3. customdried under vacuum
4. customto give a crude that
5. customis purified by column chromatography (silica gel, eluent