(4-Fluoro-2-nitro-phenylamino)-acetic acid → 7-Fluoro-1,2,3,4-tetrahydroquinoxalin-2-one

Participants

Reaction Conditions

Reaction Steps

Iron powder (6.52 g, 116.8 mmol, 5.0 eq) is added at room temperature to a stirred solution of (4-fluoro-2-nitro-phenylamino)-acetic acid (6.85 g, 23.4 mmol, 1.0 eq) in glacial acetic acid (40 mL). The resulting suspension is heated at 90° C. for 3 hours, then cooled to room temperature, diluted with ethyl acetate (40 mL), and filtered through silica gel. The filtrate is concentrated to give a crude that is purified by column chromatography (silica gel, eluent: ethyl acetate:petroleum ether, 1:3, v/v) to afford 7-fluoro-3,4-dihydro-1H-quinoxalin-2-one as a brown solid (4.01 g, 72% yield).

Provenance & Evidence