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

HRID 1019865Notes

Reaction equation

HRID 1019865 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([NH:8][CH2:9][C:10](O)=[O:11])=[C:4]([N+:13]([O-])=O)[CH:3]=1>C(O)(=O)C.C(OCC)(=O)C.[Fe]>[F:1][C:2]1[CH:3]=[C:4]2[C:5]([NH:8][CH2:9][C:10](=[O:11])[NH:13]2)=[CH:6][CH:7]=1

Participants

5

Reactant 1

HCID 23337266(4-Fluoro-2-nitro-phenylamino)-acetic acid

Product 1

HCID 229129097-Fluoro-1,2,3,4-tetrahydroquinoxalin-2-oneYield 103.1%

Reagents, catalysts & solvents 3

HCID 23925IronCatalystHCID 176Acetic AcidSolventHCID 8857Ethyl AcetateSolvent2×

Conditions

Temperature
90 °C

Procedure

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).

Workup

  1. temperaturecooled to room temperature
  2. filtrationfiltered through silica gel
  3. concentrationThe filtrate is concentrated
  4. customto give a crude that
  5. customis purified by column chromatography (silica gel, eluent

Sources & evidence

ORD record
ord-385ad5bf0f874060a964254b11200ed8
Source dataset
uspto-grants-2014_05
Patent number
US08716280B2

Reaction notes

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