Diethyl Oxalate → 5,7-Dichloro-1,4-dihydroquinoxaline-2,3-dione

HRID 439432

Reaction equation

HRID 439432 reaction equation
[C:1]([O:8]CC)(=O)[C:2]([O:4]CC)=O.[Cl:11][C:12]1[C:13]([NH2:20])=[C:14]([NH2:19])[CH:15]=[C:16]([Cl:18])[CH:17]=1>>[Cl:11][C:12]1[CH:17]=[C:16]([Cl:18])[CH:15]=[C:14]2[C:13]=1[NH:20][C:2](=[O:4])[C:1](=[O:8])[NH:19]2

Participants

3

Reactant 2

HCID 7268Diethyl OxalateHCID 42768353,5-Dichlorobenzene-1,2-diamine

Product 1

HCID 6502605,7-Dichloro-1,4-dihydroquinoxaline-2,3-dione

Procedure

The title compound (Leeson, P. D. et al., J. Med. Chem 34:1243 (1991)) was prepared using an adaptation of the method of Cheeseman. (Cheeseman, G. W. H. J. Chem. Soc. 1171 (1962)). A mixture of diethyl oxalate (4.12 g, 28.2 mmol) and 3,5-dichloro-1,2-diaminobenzene (500 mg, 2.82 mmol) was heated to reflux under N2 for 6 h. The reaction was allowed to cool to room temperature and the pale yellow shiny solid collected by vacuum filtration and rinsed with EtOH (20 mL) and air dried to give 286 mg (44%). mp 326°-328° C. (dec) Lit 337°-340° C.). 1H NMR (d6 -DMSO) δ7.05 (d, 1H, J=1.8, H-8), 7.32 (d, 1H, J=1.8, H-6), 11.5 (br s, 1H, NH), 12.1 (br s, 1H, NH). EIMS m/e 234 (M+4, 12), 232 (M+2, 67), 230 (M+, bp), 204 (52), 202 (77), 141 (19), 142 (59) EIHRMS calc. for C8H4Cl2N2O2 229.9650, found 229.9646.

Workup

  1. temperaturewas heated
  2. temperatureto reflux under N2 for 6 h
  3. filtrationthe pale yellow shiny solid collected by vacuum filtration
  4. washrinsed with EtOH (20 mL) and air
  5. customdried
  6. customto give 286 mg (44%)
  7. custommp 326°-328° C. (dec) Lit 337°-340° C.

Sources & evidence

ORD record
ord-c67323d0132f477faf761f7b0863a580
Source dataset
uspto-grants-1996_05
Patent number
US05514680

Linked notes

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