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Maleimides
Maleimide is a chemical compound with the chemical formula, formula H2C2(CO)2NH (see diagram). 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 are also a ''class'' of derivatives of the parent maleimide where the N''H'' group is replaced with alkyl or aryl groups such as a methyl or phenyl, respectively. The substituent can also be a small molecule (such as biotin, a fluorescent dye, an oligosaccharide, or a nucleic acid), a reactive group, or a synthetic polymer such as polyethylene glycol. Human hemoglobin chemically modified with maleimide-polyethylene glycol is a blood substitute called MP4. Reactions Many analogues of maleimide are prepared by treating maleic anhydride with amines followed by dehydration. A defining feature of the reactivity of maleimides is their susceptibility to additions across the double bond either by Michael additions or via D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maleic Anhydride
Maleic anhydride is an organic compound with the formula . It is the acid anhydride of maleic acid. It is a colorless or white solid with an acrid odor. It is produced industrially on a large scale for applications in coatings and polymers. Structure and bonding Maleic anhydride is a planar molecule. By virtue of the acid anhydride group, the alkene is electrophilic. On account of its cycle of 4 π electrons in an array of 5 atoms with p orbitals, maleic anhydride was long thought to exhibit antiaromaticity. However, a thermochemical study concluded that only 8 kJ/mol of destabilization energy can be ascribed to this effect, making it weakly antiaromatic at best. Production Maleic anhydride is produced by vapor-phase oxidation of butane, ''n''-butane. The overall process converts the methyl groups to carboxylate and dehydrogenation, dehydrogenates the backbone. The selectivity of the process reflects the robustness of maleic anhydride, with its conjugated double-bond system. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
