Maleamic acid

Maleamic acid is an organic compound with the formula HO₂CCH=CHC(O)NH₂. It is the amide formed by reaction of maleic anhydride with ammonia. It is a colorless solid.^[1] Maleamic acid is the product of the action of the enzyme maleimide hydrolase.

Maleamic acid

Identifiers
CAS Number	557-24-4 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:29045
ChemSpider	4444106
ECHA InfoCard	100.008.332
EC Number	209-163-4
KEGG	C01596
PubChem CID	5280451
UNII	MJS1DTX3X1
CompTox Dashboard (EPA)	DTXSID301031738
InChI InChI=1S/C4H5NO3/c5-3(6)1-2-4(7)8/h1-2H,(H2,5,6)(H,7,8)/b2-1- Key: FSQQTNAZHBEJLS-UPHRSURJSA-N
SMILES C(=C\C(=O)O)\C(=O)N
Properties
Chemical formula	C4H5NO3
Molar mass	115.088 g·mol−1
Appearance	white solid
Melting point	158–161 °C (316–322 °F; 431–434 K)
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Related compounds

A variety of maleamic acids are known. Commonly they are prepared by the reaction of an amine with maleic anhydride.^[2]

Aside from maleic anhydride, other common cyclic anhydrides (and imides) undergo ring-opening to give amido carboxylic acids. Succinic anhydride gives succinamic acid (HO₂CCH₂CH₂C(O)NH₂), citraconic anhydride gives two isomers of citraconamic acid (HO₂CCH₂CH(CH₃)C(O)NH₂ and HO₂CCH(CH₃)CH₂C(O)NH₂), and phthalimide gives phthalamidic acid (HO₂CC₆H₄C(O)NH₂).^[3]