Ethanol → 5,6,7-Trifluoro-1,4-dihydro-2,3-quinoxalinedione

HRID 1600703Notes

Reaction equation

HRID 1600703 reaction equation
[F:1][C:2]1[C:3]([NH2:11])=[C:4]([NH2:10])[CH:5]=[C:6]([F:9])[C:7]=1[F:8].[C:12](O)(=[O:16])[C:13](O)=[O:14].C(O)C>Cl>[F:1][C:2]1[C:7]([F:8])=[C:6]([F:9])[CH:5]=[C:4]2[C:3]=1[NH:11][C:12](=[O:16])[C:13](=[O:14])[NH:10]2

Participants

5

Reactant 3

HCID 702EthanolHCID 971Oxalic AcidHCID 27739583,4,5-Trifluorobenzene-1,2-diamine

Product 1

HCID 108463705,6,7-Trifluoro-1,4-dihydro-2,3-quinoxalinedioneYield 36%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Procedure

To a brown solution of 3,4,5-trifluoro-1,2-phenylenediamine (285 mg, 1.75 mmol) in aqueous 2N HCl (10 mL) is added oxalic acid (221 mg, 1.75 mmol). The brown mixture is brought to reflux and stirred under N2 overnight. The mixture is filtered to yield 139 mg (37%) of crude title compound. An analytical sample is prepared by dissolving 42 mg of this brown powder in 2.5 mL boiling ethanol. Upon cooling, brown, rod-like, crystals are formed, which are filtered and dried in vacuo to yield 15 mg (36%) of pure title compound: 1H NMR (DMSO-d6), 6.91 (m, 1H), 12.02 (s, 1H), 12.19 (s, 1H); analysis calculated for C8H3F3N2O2 : C, 44.46; H, 1.40; N, 12.96. Found: C, 44.42; H, 1.16; N, 12.76.

Workup

  1. temperatureto reflux
  2. filtrationThe mixture is filtered
  3. customto yield 139 mg (37%) of crude title compound
  4. customAn analytical sample is prepared
  5. temperatureUpon cooling
  6. custombrown, rod-like, crystals are formed
  7. filtrationwhich are filtered
  8. customdried in vacuo

Sources & evidence

ORD record
ord-77a76341fbe24a109d652e73fca198a1
Source dataset
uspto-grants-1999_11
Patent number
US05977107

Reaction notes

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