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Maleic anhydride

Maleic anhydride
IUPAC name Maleic anhydride
CAS number 108-31-6
RTECS number UE5950000
Molecular formula C4H2O3
Molar mass 98.06 g/mol
Appearance white crystals
Density 1.314 g/cm3
Melting point

53 °C, 326 K, 127 °F

Boiling point

202 °C, 475 K, 396 °F

Solubility in water 40 g/100 ml at ? °C
MSDS MSDS at J. T. Baker
EU classification Corrosive (C)
NFPA 704
R-phrases R22, R34, R42/43
S-phrases (S2), S22, S26,
S36/37/39, S45
Flash point 102 °C
Related Compounds
Related acid anhydrides Succinic anhydride
Related compounds Maleic acid
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Maleic anhydride (cis-butenedioic anhydride, toxilic anhydride, dihydro-2,5-dioxofuran) is an organic compound with the formula C4H2O3. In its pure state it is a colourless or white solid with an acrid odour.

Maleic anhydride was traditionally manufactured by the oxidation of benzene or other aromatic compounds. Due to rising benzene prices, most maleic anhydride plants now use n-butane as a feedstock. As of 2006, only few smaller plants continue to use benzene:

CH3CH2CH2CH3 + 3.5 O2 → C2H2(CO)2O + 4 H2O

Characteristic reactions

The chemistry of maleic anhydride is very rich, reflecting its ready availability and bifunctional reactivity.

  • It hydrolyzes, producing maleic acid, cis-HO2CCH=CHCO2H. With alcohols, the half-ester is generated, e.g., cis-HO2CCH=CHCO2CH3.
  • Maleic anhydride is a potent dienophile in Diels-Alder reactions.
  • Maleic anhydride (MA) is an excellent ligand for low-valent metal complexes, examples being Pt(PPh3)2(MA) and Fe(CO)4(MA).


    This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Maleic_anhydride". A list of authors is available in Wikipedia.
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