Allophanic acid

(Redirected from Allophanate)

Allophanic acid is the organic compound with the formula H2NC(O)NHCO2H. It is a carbamic acid, the carboxylated derivative of urea. Biuret can be viewed as the amide of allophanic acid. The compound can be prepared by treating urea with sodium bicarbonate:[1]

Allophanic acid
Names
Preferred IUPAC name
Carbamoylcarbamic acid
Identifiers
3D model (JSmol)
3DMet
1756623
ChEBI
ChemSpider
KEGG
UNII
  • InChI=1S/C2H4N2O3/c3-1(5)4-2(6)7/h(H,6,7)(H3,3,4,5)
    Key: AVWRKZWQTYIKIY-UHFFFAOYSA-N
  • C(=O)(N)NC(=O)O
Properties
C2H4N2O3
Molar mass 104.065 g·mol−1
Appearance white solid
Melting point 114 °C (237 °F; 387 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
H2NC(O)NH2 + NaHCO3 → H2NC(O)NHCO2H + NaOH

The anionicconjugate base, H2NC(O)NHCO2, is called allophanate. Salts of this anion have been characterized by X-ray crystallography.[2][3] The allophanate anion is the substrate for the enzyme allophanate hydrolase.

Allophanate esters arise from the condensation of carbamates.

References

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  1. ^ Karachinskii, S. V.; Dragalov, V. V.; Chimishkyan, A. L.; Tsvetkov, V. Yu. (1987). "Reaction of urea with alkali metal carbonates". Zhurnal Organicheskoi Khimii. 23: 93–6.  
  2. ^ Mak, Thomas C. W.; Yip, Wai Hing; Li, Qi (1995). "Novel Hydrogen-Bonded Host Lattices Built of Urea and the Elusive Allophanate Ion". Journal of the American Chemical Society. 117 (48): 11995–11996. doi:10.1021/ja00153a022.
  3. ^ Li, Qi; Mak, Thomas C. W. (1996). "A Novel Inclusion Compound Consolidated by Host-host and Host-guest Hydrogen Bonding: (2-hydro-xyethyl)trimethylammonium Ions Included in a Channel Host Lattice Built of Urea Molecules and Allophanate Ions". Supramolecular Chemistry. 8: 73–80. doi:10.1080/10610279608233970.