Triuret is an organic compound with the formula (H2NC(O)NH)2CO. It is a product from the pyrolysis of urea. Triuret is a colorless, crystalline, hygroscopic solid, slightly soluble in cold water or ether, and more soluble in hot water. It is a planar molecule. The central carbonyl is hydrogen-bonded to both terminal amino groups.D. Carlström and H. Ringertz "The molecular and crystal structure of triuret" Acta Crystallogr. (1965. vol. 18, 307-313.
Synthesis The compound is typically prepared by heating thin layers of urea, the thin layers facilitating escape of ammonia: 3 (H2N)2CO → [H2NC(O)NH]2CO + 2 NH3 It can also prepared by treatment of urea with phosgene: 2 (H2N)2CO + COCl2 → [H2NC(O)NH]2CO + 2 HCl A similar synthesis employs urea and dimethyl carbonate with potassium methoxide as a catalyst: 2 (H2N)2CO + CO(OCH3)2 → [H2NC(O)NH]2CO + 2 MeOH
The original synthesis entailed oxidation of uric acid with hydrogen peroxide.Alfred Schittenhelm, Karl Wiener "Carbonyldiharnstoff als Oxydationsprodukt der Harnsäure" Zeitschrift für Physiologische Chemie 1909, volume 62, 100 ff.
Triuret is a complicating by-product in the industrial synthesis of melamine from urea.
Related compounds Urea Biuret Cyanuric acid
References