maleamic acid
{{Chembox
| ImageFile = MaleamicAcid.svg
| ImageSize =
| ImageAlt =
| IUPACName =
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo = 557-24-4
| CASNo_Ref = {{cascite|correct|CAS}}
| ChEBI = 29045
| ChemSpiderID = 4444106
| EC_number = 209-163-4
| KEGG = C01596
| PubChem = 5280451
| UNII = MJS1DTX3X1
| StdInChI=1S/C4H5NO3/c5-3(6)1-2-4(7)8/h1-2H,(H2,5,6)(H,7,8)/b2-1-
| StdInChIKey = FSQQTNAZHBEJLS-UPHRSURJSA-N
| SMILES = C(=C\C(=O)O)\C(=O)N
}}
|Section2={{Chembox Properties
| C = 4|H=5|O=3|N=1
| MolarMass =
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| Appearance = white solid
| Density =
| MeltingPtC = 158 - 161
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| Solubility = }}
|Section3={{Chembox Hazards
| GHS_ref=[https://pubchem.ncbi.nlm.nih.gov/compound/5280451#section=Safety-and-Hazards]
| GHSPictograms = {{GHS07}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|315|319|335}}
| PPhrases = {{P-phrases|261|264|264+265|271|280|302+352|304+340|305+351+338|319|321|332+317|337+317|362+364|403+233|405|501}}
| MainHazards =
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Maleamic acid is an organic compound with the formula {{chem2|HO2CCH\dCHC(O)NH2}}. It is the amide formed by reaction of maleic anhydride with ammonia. It is a colorless solid.{{cite book |doi=10.1002/0471238961.1301120506051220.a01.pub3 |chapter=Maleic Anhydride, Maleic Acid, and Fumaric Acid |title=Kirk-Othmer Encyclopedia of Chemical Technology |date=2024 |last1=Hood |first1=David K. |pages=1–51 |isbn=978-0-471-48494-3 }} Maleamic acid is the product of the action of the enzyme maleimide hydrolase.
Related compounds
A variety of maleamic acids are known. Commonly they are prepared by the reaction of an amine with maleic anhydride.{{cite journal |doi=10.1021/jo01076a038 |title=Maleamic and Citraconamic Acids, Methyl Esters, and Imides |date=1960 |last1=Mehta |first1=Nariman B. |last2=Phillips |first2=Arthur P. |last3=Lui |first3=(MRS.) Florence FU |last4=Brooks |first4=Ronald E. |journal=The Journal of Organic Chemistry |volume=25 |issue=6 |pages=1012–1015 }}
Aside from maleic anhydride, other common cyclic anhydrides (and imides) undergo ring-opening to give amido carboxylic acids. Succinic anhydride gives succinamic acid ({{chem2|HO2CCH2CH2C(O)NH2}}), citraconic anhydride gives two isomers of citraconamic acid ({{chem2|HO2CCH2CH(CH3)C(O)NH2}} and {{chem2|HO2CCH(CH3)CH2C(O)NH2}}), and phthalimide gives phthalamidic acid ({{chem2|HO2CC6H4C(O)NH2}}).{{cite journal |doi=10.1021/cr60266a001 |title=Cyclic Carboxylic Monoimides |date=1970 |last1=Hargreaves |first1=Michael K. |last2=Pritchard |first2=J. G. |last3=Dave |first3=H. R. |journal=Chemical Reviews |volume=70 |issue=4 |pages=439–469 }}