Methane → 5-Chloro-7-fluoro-1,4-dihydro-2,3-quinoxalinedione

HRID 54288Notes

Reaction equation

HRID 54288 reaction equation
[C:1]([O:8]CC)(=O)[C:2]([O:4]CC)=O.[NH2:11][C:12]1[CH:17]=[C:16]([F:18])[CH:15]=[C:14]([Cl:19])[C:13]=1[NH2:20].C>[OH-].[Na+]>[Cl:19][C:14]1[CH:15]=[C:16]([F:18])[CH:17]=[C:12]2[C:13]=1[NH:20][C:2](=[O:4])[C:1](=[O:8])[NH:11]2

Participants

5

Reactant 3

HCID 297MethaneHCID 7268Diethyl OxalateHCID 153457433-Chloro-5-fluorobenzene-1,2-diamine

Product 1

HCID 153457445-Chloro-7-fluoro-1,4-dihydro-2,3-quinoxalinedione

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

5-Chloro-7-fluoro-1,4-dihydro-2,3-quinoxalinedione was prepared using an adaptation of the method of Cheeseman. (Cheeseman, G. W. H. J. Chem. Soc. 1171 (1962)). A mixture of diethyl oxalate (2.64 g, 18.1 mmol) and 1,2-diamino-3-chloro-5-fluorobenzene (290 mg, 1.81 mmol) was heated to reflux under N2 for 10 h. The reaction was allowed to cool to room temperature and the shiny yellow-brown crystals collected by vacuum filtration and rinsed with EtOH (10 mL) and air dried to give 164.1 mg (42%). A portion of this solid was taken and dissolved in 10 mL 1N NaOH. The solution was treated with activated charcoal and filtered through a pad of Celite. The resulting solution was carefully acidified with 1N HCl (pH=6). Pale yellow needles slowly formed in the solution and were collected by vacuum filtration, rinsed with 20 mL of H2O and further dried under vacuum (0.1 torr, 78° C.) to yield 67.8 of powdery pale yellow crystals. mp 306°-308° C. (dec), 1H NMR (d6 -DMSO) δ7.28 (s, 1H, ArH), 7.56 (s, 1H, ArH), 11.7 (br s, 2H, NH), EIMS m/z 216 (M+2,34, 214 (M+, bp), 188 (21), 186 (68), 123 (61), 131 (62). EIHRMS calc. for C8H4ClFN2O2 213.9945, found 213.9961.

Workup

  1. temperaturewas heated
  2. temperatureto reflux under N2 for 10 h
  3. filtrationthe shiny yellow-brown crystals collected by vacuum filtration
  4. washrinsed with EtOH (10 mL) and air
  5. customdried
  6. customto give 164.1 mg (42%)
  7. filtrationfiltered through a pad of Celite
  8. customPale yellow needles slowly formed in the solution
  9. filtrationwere collected by vacuum filtration
  10. washrinsed with 20 mL of H2O
  11. customfurther dried under vacuum (0.1 torr, 78° C.)

Sources & evidence

ORD record
ord-7662a00a0fdf4fa0adbd540b1b9edfdc
Source dataset
uspto-grants-1997_04
Patent number
US05622952

Reaction notes

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