) | |
| Names | |
|---|---|
| Preferred IUPAC name (2Z)-2-Methylbut-2-enedioic acid | |
| Other names 2-Methylmaleic acid Citraconate Methylmaleic acid cis-Methylbutenedioic acid | |
| Identifiers | |
3D model (JSmol) | |
| 3DMet | |
| ChEBI | |
| ChemSpider | |
| DrugBank | |
| ECHA InfoCard | 100.007.145  |
| EC Number |
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| KEGG | |
PubChem CID | |
| UNII | |
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SMILES
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| Properties | |
Chemical formula | C5H6O4 |
| Molar mass | 130.099 g·mol−1 |
| Appearance | Monoclinic crystals[1] |
| Density | 1.62 g/cm3[1] |
| Melting point | ~90 °C (decomposition)[1] |
| Freely soluble[1] | |
| Hazards | |
| GHS pictograms | ) |
| GHS Signal word | Warning |
GHS hazard statements | H302 |
GHS precautionary statements | P264, P270, P301+312, P330, P501 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Citraconic acid is an organic compound with the formula CH3C2H(CO2H)2. It is a white solid. It is the cis-isomer of mesaconic acid. It is one of the pyrocitric acids formed upon the heating of citric acid.[1] Citraconic acid can be produced, albeit inefficiently, by oxidation of xylene and methylbutanols. The acid displays the unusual property of spontaneously forming the anhydride, which, unlike maleic anhydride, is a liquid at room temperature.[2]
)
Steps in conversion of citric acid to citraconic acid.
In the laboratory, citraconic acid can be produced by thermal isomerization of itaconic acid anhydride to give citraconic anhydride, which can be hydrolyzed to citraconic acid.[3] The required itaconic acid anhydride is obtained by dry distillation of citric acid.
References
- ^ a b c d e Budavari, Susan, ed. (1996), The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (12th ed.), Merck, ISBN 0911910123
- ^ Kurt Lohbeck; Herbert Haferkorn; Werner Fuhrmann; Norbert Fedtke. "Maleic and Fumaric Acids". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a16_053.
- ^ R. L. Shriner; S. G. Ford; l. J. Roll (1931). "Citraconic Anhydride and Citraconic Acid". Org. Synth. 28: 28. doi:10.15227/orgsyn.011.0028.