1H-Imidazole-2-carboxylic acid → 5H,10H-Diimidazo[1,2-a:1',2'-d]pyrazine-5,10-dione

HRID 1702919Notes

Reaction equation

HRID 1702919 reaction equation
[NH:1]1[CH:5]=[CH:4][N:3]=[C:2]1[C:6]([OH:8])=O>S(Cl)(Cl)=O>[N:3]1[CH:4]=[CH:5][N:1]2[C:6](=[O:8])[C:2]3=[N:1][CH:5]=[CH:4][N:3]3[C:6](=[O:8])[C:2]=12

Participants

3

Reactant 1

HCID 5743211H-Imidazole-2-carboxylic acid

Product 1

HCID 126303345H,10H-Diimidazo[1,2-a:1',2'-d]pyrazine-5,10-dione

Reagents, catalysts & solvents 1

HCID 24386Thionyl ChlorideSolvent

Procedure

11.2 g (0.1 mol) of imidazole-2-carboxylic acid [which could be prepared, for example, in accordance with the method of J. Am. Chem. Soc., 71, 383 (1949)] were stirred under reflux with 100 ml of thionyl chloride for 5 hours. After cooling the mixture, the solid was filtered off, washed with a little petroleum ether and dried. 5H, 10H-diimidazo[1,2-a:1',2'-d]pyrazine-5,10-dione was thus obtained in virtually quantitative yield in the form of a yellow powder. The substance still did not melt at 290° C. It could be sublimed into yellow crystals at 200°-250° C./0.01 mm Hg without decomposition. IR (KBr): 3137, 1735, 1522, 1445, 1387, 1331, 1274, 1161, 1059, 1018, 810, 800, 748, 699 and 651 cm-1.

Workup

  1. temperatureAfter cooling the mixture
  2. filtrationthe solid was filtered off
  3. washwashed with a little petroleum ether
  4. customdried

Sources & evidence

ORD record
ord-8eee8d37a5434c6b9e04460da4d3a6e7
Source dataset
uspto-grants-1982_09
Patent number
US04350520

Reaction notes

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