Title: Maleic Acid
CAS Registry Number: 110-16-7
CAS Name: (Z)-Butenedioic acid
Additional Names: toxilic acid; cis-1,2-ethylenedicarboxylic acid
Molecular Formula: C4H4O4
Molecular Weight: 116.07
Percent Composition: C 41.39%, H 3.47%, O 55.14%
Literature References: Prepd by the catalytic oxidation of benzene over vanadium pentoxide: Bhattacharyya, Venkataraman, J. Appl. Chem. 8, 728 (1958); Saffer, Olenberg, FR 1321416 (1963 to Scientific Design), C.A. 59, 11265d (1963). Crystal structure: Shahat, Acta Crystallogr. 5, 763 (1952). Review: W. D. Robinson, R. A. Mount in Kirk-Othmer Encyclopedia of Chemical Technology vol. 14 (Wiley-Interscience, New York, 3rd ed., 1981) pp 770-793.
Properties: White crystals from water, mp 138-139°; from alcohol and benzene, mp 130-131°. Faint, acidulous odor; characteristic repulsive, astringent taste. d 1.59. Is converted in part into the much higher-melting fumaric acid (mp 287°) when heated to a temp slightly above the melting point. Freely sol in water or alcohol. Sol in acetone, glacial acetic acid. Slightly sol in ether. Practically insol in benzene.
Melting point: mp 138-139°; mp 130-131°
Density: d 1.59
CAUTION: Strong irritant.
Use: Manuf artificial resins; to retard rancidity of fats and oils in 1:10,000 (these are said to keep 3 times longer than those without the acid); dyeing and finishing wool, cotton, and silk; preparing the maleate salts of antihistamines and similar drugs.