Maleimide

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Maleimide

IUPAC name	Maleimide
Other names	2,5-Pyrroledione
Identifiers
CAS number	[541-59-3]
Properties
Molecular formula	C₄H₃NO₂
Molar mass	97.07 g/mol
Melting point	91-93 °C
Solubility in water	organic solvents
Hazards
R-phrases	R25 R34 R43
S-phrases	S26 S36/37/39 S45
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Maleimide is the chemical compound with the formula H₂C₂(CO)₂NH. This unsaturated imide is an important building block in organic synthesis. The name is a contraction of maleic acid and imide, the -C(O)NHC(O)- functional group. Maleimides also describes a class of derivatives of the parent maleimide where the NH group is replaced with alkyl or aryl groups such as a methyl or phenyl. The substituent can also be a polymer such as polyethylene glycol. Human hemoglobin chemically modified with maleimide-polyethylene glycol is a blood substitute called MP4.

1 Organic chemistry
2 Biotechnology applications
3 Technological applications
4 See also
5 References
6 External links

[edit] Organic chemistry

Maleimide and its derivatives are prepared from maleic anhydride by treatment with amines followed by dehydration.^[1] A special feature of the reactivity of maleimides is their susceptibility to additions across the double bond either by Michael additions or via Diels-Alder reactions. Bismaleimides are a class of compounds with two maleimide groups connected through a molecular unit and used as crosslinking reagents in polymer chemistry.

[edit] Biotechnology applications

Maleimides linked to polyethylene glycol chains are often used as flexible linking molecules to attach proteins to surfaces. The double bond readily reacts with the thiol group found on cysteine to form a stable carbon-sulfur bond. Attaching the other end of the polyethylene chain to a bead or solid support allows for easy separation of protein from other molecules in solution, provided these molecules do not also possess thiol groups.

[edit] Technological applications

Mono- and bismaleimides are used for high temperature applications up to 250°C.^{[citation needed]} Maleimides linked to rubber chains are often used as flexible linking molecules to reinforce the rubber (tire). The double bond readily reacts with all hydroxy, amine or thiol groups found on the matrix to form a stable carbon-sulfur, carbon-nitrogen or carbon-carbon bond.