Diethyl Oxalate → 5,6,7,8-Tetrachloro-1,4-dihydro-2,3-quinoxalinedione

HRID 54303Notes

Reaction equation

HRID 54303 reaction equation
[C:1]([O:8]CC)(=O)[C:2]([O:4]CC)=O.[NH2:11][C:12]1[C:17]([Cl:18])=[C:16]([Cl:19])[C:15]([Cl:20])=[C:14]([Cl:21])[C:13]=1[NH2:22]>>[Cl:18][C:17]1[C:16]([Cl:19])=[C:15]([Cl:20])[C:14]([Cl:21])=[C:13]2[C:12]=1[NH:11][C:2](=[O:4])[C:1](=[O:8])[NH:22]2

Participants

3

Reactant 2

HCID 7268Diethyl OxalateHCID 2817911,2-Diamino-3,4,5,6-tetrachlorobenzene

Product 1

HCID 3337015,6,7,8-Tetrachloro-1,4-dihydro-2,3-quinoxalinedione

Procedure

5,6,7,8-Tetrachloro-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 (2.97 g, 20.0 mmol) and 1,2-diamino-3,4,5,6-tetrachlorobenzene (500 mg, 2.03 mmol) was heated to reflux under N2 for 6 h. The reaction was allowed to cool to room temperature and the orange solid collected by vacuum filtration and rinsed with cold EtOH (10 mL) and air dried. This solid was recrystallized from abs. ethanol to give 97.0 mg (16%) of an orange solid mp 326°-328° C. (dec). (Lit., >360°). FT-IR: 3198, 3135 cm-1 (N--H), 1750, 1623 cm-1 (C=O). 1H NMR δ (d6 -DMSO) δ11.7 (br s, 2H, N--H) EIMS m/z 306 (M+8, 1.7), 304 (M+6, 11.5), 302 (M+4, 47.4), 300 (M+2, 93.9), 288 (M+, 76.7), 274 (50.0), 272 (bp), 270 (79.0), 209 (61.0), 207 (64.0). EIHRMS calc. for C8H2Cl4N2O2 297.8870, found 297.8864.

Workup

  1. temperaturewas heated
  2. temperatureto reflux under N2 for 6 h
  3. filtrationthe orange solid collected by vacuum filtration
  4. washrinsed with cold EtOH (10 mL) and air
  5. customdried
  6. customThis solid was recrystallized from abs

Sources & evidence

ORD record
ord-fe2352b82fcf417d854a95372a5c39f7
Source dataset
uspto-grants-1997_04
Patent number
US05622952

Reaction notes

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