Mesoxalic acid

Mesoxalic acid
IUPAC name oxopropanedioic acid
Other names Ketomalonic acid Oxomalonic acid Alpha-ketomalonic acid 2-Oxopropanedioic acid
Identifiers
CAS number	473-90-5
PubChem	10132
ChemSpider	9727 Y
DrugBank	DB03589
KEGG	C00830 Y
ChEBI	CHEBI:30842 Y
Jmol-3D images	Image 1
SMILES O=C(O)C(=O)C(=O)O
InChI InChI=1S/C3H2O5/c4-1(2(5)6)3(7)8/h(H,5,6)(H,7,8) Y Key: XEEVLJKYYUVTRC-UHFFFAOYSA-N Y InChI=1/C3H2O5/c4-1(2(5)6)3(7)8/h(H,5,6)(H,7,8) Key: XEEVLJKYYUVTRC-UHFFFAOYAW
Properties
Molecular formula	C3H2O5
Molar mass	118.04 g mol−1
Y acid (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Mesoxalic acid, also called oxomalonic acid or ketomalonic acid, is an organic compound with formula C₃H₂O₅ or HO-(C=O)₃-OH.

Mesoxalic acid is both a dicarboxylic acid and a ketonic acid. It readily loses two protons to yield the divalent anion C₃O₅²⁻, called mesoxalate, oxomalonate, or ketomalonate. These terms are also used for salts containing this anion, such as sodium mesoxalate, Na₂C₃O₅); and for esters containing the -C₃O₅- or -O-(C=O)₃-O- moiety, such as diethyl mesoxalate, C₂H₅)₂C₃O₅. Mesoxalate is one of the oxocarbon anions, which (like carbonate CO₃²⁻ and oxalate C₂O₄²⁻) consist solely of carbon and oxygen.

Mesoxalic acid readily absorbs and reacts with water to form a product commonly called "mesoxalic acid (mono)hydrate", more properly dihydroxymalonic acid, HO-(C=O)-C(OH)₂-(C=O)-OH.^[1] In product catalogs and other contexts, the terms "mesoxalic acid", "oxomalonic acid", etc. often refer to this "hydrated" compound. In particular, the product traded as "sodium mesoxalate monohydrate" is almost always sodium dihydroxymalonate.

Synthesis

Mesoxalic acid can be obtained synthetically by hydrolysis of alloxan with baryta water,^[1] by warming caffuric acid with lead acetate solution,^[1] or from glycerin diacetate and concentrated nitric acid in the cold. The product can be obtained also by oxidation of tartronic acid ^[2] or glycerol.^[3] Since they are carried out in water, these procedures generally give the dihydroxy derivative.

See also

• Malonic acid

References

1. ^ ^{a b c} Henry Enfield Roscoe (1888), A Treatise on Chemistry, volume 3, part2 Organic Chemistry, p. 161. D. Appleton and Co., New York.
2. ^ Rosaria Ciriminna and Mario Pagliaro (2004), Oxidation of tartronic acid and dihydroxyacetone to sodium mesoxalate mediated by TEMPO. Tetrahedron Letters, volume 45, issue 34, pp. 6381–6383. doi:10.1016/j.tetlet.2004.07.021
3. ^ Rosaria Ciriminna and Mario Pagliaro (2003), One-Pot Homogeneous and Heterogeneous Oxidation of Glycerol to Ketomalonic Acid Mediated by TEMPO. Advanced Synthesis & Catalysis, volume 345, issue 3, Pages 383–388. doi:10.1002/adsc.200390043