110-16-7

MALEIC ACID(110-16-7) is a colorless crystalline solid having a faint odor. MALEIC ACID(110-16-7) is combustible though MALEIC ACID(110-16-7) may take some effort to ignite. MALEIC ACID(110-16-7) is soluble in water. MALEIC ACID(110-16-7) is used to make other chemicals and for dyeing and finishing naturally occurring fibers.

MALEIC ACID is a colorless to white crystalline solid. Moderately toxic. When heated to decomposition MALEIC ACID emits irritating fumes and acrid smoke [Lewis, 3rd ed., 1993, p. 790].

Soluble in water.

Toxic by ingestion.

Inhalation causes irritation of nose and throat. Contact with eyes or skin causes irritation.

Maleic acid is used to make artificial resins, antihistamines, and to preserve (retard rancidity) of fats and oils

Special Hazards of Combustion Products: Irritating smoke containing maleic anhydride may form in fire.

If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 30 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, remove contaminated clothing and wash immediately with soap and water. Seek medical attention immediately If this chemical has been inhaled, remove from exposure, begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if heart action has stopped. Transfer promptly to a medical facility. When this chemical has been swallowed, get medical attention. If victim is conscious, administer water or milk. Do not induce vomiting. Medical observation is recommended for 24 to 48 hours after breathing overexposure, as pulmonary edema may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or other inhalation therapy.

UN2215 Maleic acid, Hazard class: 8; Labels: 8-Corrosive material.

Dust may form explosive mixture with air, Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, amines, reducing agents; alkali metals

Maleic acid (cas: 110-16-7) is an organic compound that is a dicarboxylic acid, a molecule with two carboxyl groups. Its chemical formula is HO₂CCHCHCO₂H. Maleic acid is the cis-isomer of butenedioic acid, where as fumaric acid is the trans-isomer. It is mainly used as a precursor to fumaric acid, and relative to its parent maleic anhydride, maleic acid has few applications.

Maleic acid is a white crystalline solid. Faint, acid like odor.

Maleic acid occurs as a white crystalline (monoclinic) powder and possesses a faint acidulous odor and an astringent taste.
Fumaric acid and maleic acid are the simplest unsaturated carboxylic diacids. These acids experience two-step dissociation in aqueous solutions.They have the same structural formula but different spatial configurations. Fumaric acid is the trans and maleic acid the cis isomer. The physical properties of maleic acid and fumaric acid are very different. The cis isomer is less stable. Maleic acid is used in the preparation of fumaric acid by catalytic isomerization.

Maleic acid, HOOCCH:CHCOOH, also known as maleinic acid and toxilic acid,is a colorless crystalline dibasic acid. It is soluble in water and alcohol. Maleic acid is used in manufacturing synthetic resins, in textile processing, and in preserving oils and fats.

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed. Liquid: incinerate after mixing with a flammable solvent. Use afterburner for complete combustion. Solid: dissolve in a flammable solvent or package in paper and burn. See above

Maleic acid is a less stable molecule than fumaric acid. The difference in heat of combustion is 22.7 kJ·mol?1. The heat of combustion is -1355 kJ / mole. Maleic acid is more soluble in water than fumaric acid. The melting point of maleic acid (135 °C) is also much lower than that of fumaric acid (287 °C). Both properties of maleic acid can be explained on account of the intramolecular hydrogen bonding that takes place in maleic acid at the expense of intermolecular interactions, and that are not possible in fumaric acid for geometric reasons.

Maleic acid is an industrial raw material for the production of glyoxylic acid by ozonolysis. It may be used to form acid addition salts with drugs to make them more stable, such as indacaterol maleate. Maleic acid is also used in manufacturing synthetic resins; in textile processing; in preserving oils and fats; 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.

ChEBI: A butenedioic acid in which the double bond has cis- (Z)-configuration.

Maleic anhydride is the main source of maleic acid produced by hydration. Maleic anhydride is prepared commercially by the oxidation of benzene or by the reaction of butane with oxygen in the presence of a vanadium catalyst.

Although not practised commercially, maleic acid can be converted into maleic anhydride by dehydration, to malic acid by hydration, and to succinic acid by hydrogenation (ethanol / palladium on carbon). It reacts with thionyl chloride or phosphorus pentachloride to give the maleic acid chloride (it is not possible to isolate the mono acid chloride). Maleic acid, being electrophilic, participates as a dienophile in many Diels - Alder reactions.

Journal of the American Chemical Society, 86, p. 4603, 1964 DOI: 10.1021/ja01075a017
The Journal of Organic Chemistry, 60, p. 6676, 1995 DOI: 10.1021/jo00126a013
Organic Syntheses, Coll. Vol. 2, p. 302, 1943

Nonflammable

Maleic acid is used in the pharmaceutical industry as a pH modifier and a buffering agent.It is also used to prevent rancidity of oils and fats; a ratio of 1 : 10 000 is usually sufficient to retard rancidity. Maleic acid is commonly used as a pharmaceutical intermediate to form the maleate salts of several categories of therapeutic agents, such as salts of antihistamines and other drug substances.

Maleic acid is generally regarded as a nontoxic and nonirritant material when used at low levels as an excipient. Maleic acid is used in oral, topical, and parenteral pharmaceutical formulations in addition to food products.
LD₅₀ (mouse, oral): 2.40g/kg(7)
LD₅₀ (rabbit, skin): 1.56g/kg
LD₅₀ (rat, oral): 0.708g/kg

In chronic feeding studies, 12 Osborne–Mendel rats per group were fed 0.5, 1.0, or 1.5% maleic acid in their diets for 2 years. Concentrations of 1.0 and 1.5% maleic acid retarded the growth rate of rats, and all concentrations of maleic acid increased mortality rate; no tumorigenesis was reported. Toxicological differences from controls were not marked, and the pathology was nonspecific.

Maleic acid converts into the much higher-melting fumaric acid (mp: 287°C) when heated to a temperature slightly above its melting point.
Maleic acid is combustible when exposed to heat or flame. The bulk material should be stored in airtight glass containers and protected from light. It is recommended not to store it above 25°C.

Crystallise the acid from acetone/pet ether (b 60-80o) or hot water. Dry it at 100o. [Beilstein 2 H 748, 2 I 303, 2 II 641, 2 III 1911, 2 IV 2199.]

Included in the FDA Inactive Ingredients Database (IM and IV injections; oral tablets and capsules; topical applications). Included in nonparenteral and parenteral medicines licensed in the UK.