Diethyl Oxalate → 6,7-Difluoroquinoxaline-2,3(1H,4H)-dione

HRID 54309

Reaction equation

HRID 54309 reaction equation
[C:1]([O:8]CC)(=O)[C:2]([O:4]CC)=O.[F:11][C:12]1[C:17]([F:18])=[CH:16][C:15]([NH2:19])=[C:14]([NH2:20])[CH:13]=1>>[F:11][C:12]1[CH:13]=[C:14]2[C:15](=[CH:16][C:17]=1[F:18])[NH:19][C:1](=[O:8])[C:2](=[O:4])[NH:20]2

Participants

3

Reactant 2

HCID 7268Diethyl OxalateHCID 27367551,2-Diamino-4,5-difluorobenzene

Product 1

HCID 8228396,7-Difluoroquinoxaline-2,3(1H,4H)-dione

Procedure

The title compound (Sarges, R. et al., J. Med. Chem. 33:2240 (1990)) was prepared using an adaptation of the method of Cheeseman. (Cheeseman, G. W. H. J. Chem. Soc. 1171 (1962)). A mixture of diethyl oxalate (1.11 g, 7.63 mmol and 4,5-difluoro-1,2-diaminobenzene (110 mg, 0.763 mmol) was heated to reflux under N2 for 2 h. The reaction was allowed to cool to room temperature and the solid collected by vacuum filtration and rinsed with hexanes and air dried. This ;gray brown solid was recrystallized from 20 ml of EtOH and the brown-white crystals collected by vacuum filtration and the crystals further dried under vacuum (0.5 torr, 25° C.) to yield 45.3 mg (30.0%) mp>360° C. (lit.>310° C.). 1H NMR (d6 -acetone) δ7.19 (t, 2H, ArH, JH-F =9.3), 10.9 (br s, 2H, NH).

Workup

  1. temperaturewas heated
  2. temperatureto reflux under N2 for 2 h
  3. filtrationthe solid collected by vacuum filtration
  4. washrinsed with hexanes and air
  5. customdried
  6. customThis ;gray brown solid was recrystallized from 20 ml of EtOH
  7. filtrationthe brown-white crystals collected by vacuum filtration
  8. customthe crystals further dried under vacuum (0.5 torr, 25° C.)
  9. customto yield 45.3 mg (30.0%) mp>360° C. (lit.>310° C.)

Sources & evidence

ORD record
ord-9af37f6fb3934d89ab71b2d2bf8b1ce5
Source dataset
uspto-grants-1997_04
Patent number
US05622952

Linked notes

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