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Fumaric acid

Fumaric acid
Skeletal formula of fumaric acid
Ball-and-stick model of the fumaric acid molecule
Names
Preferred IUPAC name
(2E)-But-2-enedioic acid
Other names
Fumaric acid
trans-1,2-Ethylenedicarboxylic acid
2-Butenedioic acid
trans-butenedioic acid
Allomaleic acid
Boletic acid
Donitic acid
Lichenic acid
Identifiers
110-17-8 YesY
3D model (Jmol) Interactive image
ChEBI CHEBI:18012 YesY
ChEMBL ChEMBL503160 YesY
ChemSpider 10197150 YesY
DrugBank DB04299 YesY
ECHA InfoCard 100.003.404
EC Number 203-743-0
E number E297 (preservatives)
KEGG C00122 YesY
UNII 88XHZ13131 YesY
Properties
C4H4O4
Molar mass 116.07 g·mol−1
Appearance White solid
Density 1.635 g/cm3
Melting point 287 °C (549 °F; 560 K) (decomp)
4.9 g/L at 20°C
Acidity (pKa) pka1 = 3.03, pka2 = 4.44
-49.11·10−6 cm3/mol
Pharmacology
D05AX01 (WHO)
Hazards
Irritant (Xi)
R-phrases R36
S-phrases (S2)-S26
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Related compounds
maleic acid
succinic acid
crotonic acid
Related compounds
fumaryl chloride
fumaronitrile
dimethyl fumarate
iron(II) fumarate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY  (what is YesYN ?)
Infobox references

Fumaric acid or trans-butenedioic acid is the chemical compound with the formula HO2CCH=CHCO2H. This white crystalline compound is one of two isomeric unsaturated dicarboxylic acids, the other being maleic acid. In fumaric acid the carboxylic acid groups are trans (E) and in maleic acid they are cis (Z). Fumaric acid has a fruit-like taste.

The salts and esters are known as fumarates. Fumarate can also refer to the C4H2O4−− ion (in solution).

Fumaric acid was first prepared from succinic acid. A traditional synthesis involves oxidation of furfural (from the processing of maize) using chlorate in the presence of a vanadium-based catalyst. Currently, industrial synthesis of fumaric acid is mostly based on catalytic isomerisation of maleic acid in aqueous solutions at low pH. Maleic acid is accessible in large volumes as a hydrolysis product of maleic anhydride, produced by catalytic oxidation of benzene or butane.

The chemical properties of fumaric acid can be anticipated from its component functional groups. This weak acid forms a diester, it undergoes additions across the double bond, and it is an excellent dienophile.

Fumaric acid does not combust in a bomb calorimeter under conditions where maleic acid deflagrates smoothly. For teaching experiments designed to measure the difference in energy between the cis- and trans- isomers, a measured quantity of carbon can be ground with the subject compound and the enthalpy of combustion computed by difference.


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