Maleamic acid derivatives

Arylhydrazones 111 and enamines 112 also reportedly yield maleamic acid derivatives on reaction with MA. In some cases, the initial... 

Azines were also examined by Snyder et al. Benzaldehyde azine (benzalazine) with MA in ether saturated with water gave a maleamic acid derivative 21 in a 78% yield. Maleamic acid formation suggests that the rate of azine hydrolysis may be faster than that of MA under these conditions. 

Dutt and Guha have examined cyclohexanone azine 23 and observed that the nature of the product is dependent on the reaction conditions. In ether, 23 and MA gave the maleamic acid derivative similar to that obtained by Caronna. " On the other hand, in aromatic solvents the criss-cross adduct... 

Amidation. Reaction of maleic anhydride or its isomeric acids with ammonia [7664-41-7] (qv), primary amines (qv), and secondary amines produces mono- or diamides. The monoamide derivative from the reaction of ammonia and maleic anhydride is called maleamic acid [557-24-4] (8). Another monoamide derivative formed from the reaction of aniline [62-53-3] and maleic anhydride is maleanilic acid [555-59-9] (9). 

Photosensitive functions are in many cases also heat sensitive, so the preparation of photosensitive polyimides needs smooth conditions for the condensations and imidization reactions. Some chemical reactants, which can be used for polyamide preparation, have been patented for the synthesis of polyimides and polyimide precursors. For example, chemical imidization takes place at room temperature by using phosphonic derivative of a thiabenzothiazoline.102 A mixture of N -hydroxybenzotriazole and dicyclohexylcarbodiimide allows the room temperature condensation of diacid di(photosensitive) ester with a diamine.103 Dimethyl-2-chloro-imidazolinium chloride (Fig. 5.25) has been patented for the cyclization of a maleamic acid in toluene at 90°C.104 The chemistry of imidazolide has been recently investigated for the synthesis of polyimide precursor.105 As shown in Fig. 5.26, a secondary amine reacts with a dianhydride giving meta- and para-diamide diacid. The carbonyldiimidazole... 

Scheme 4 Polycarbobetaines derived from alternating copolymers of maleic or maleamic acid...

Carbobetaine units are employed in many copolymers with uncharged monomers. Examples are the alternating copolymers of la (n = 1) [47], 4 [20] or 5 [21] with SO2, or alternating copolymers 22 with betaine structures derived from maleamic acid [48,49]. 

Structural studies of polymer surfaces. Materials that have been studied include PMMA [239], PMMA-polypyrrole composites [240], polyfchloromethyl styrene) honnd 1,4,8,11-tetrazacyclotetradecane, polyfchloromethyl styrene) honnd thenoyl triflnoroacetone [241], poly(dimethyl siloxane)-polyamide copolymers [242], PS [243], ion-implanted PE [244], monoazido-terminated polyethylene oxide [245], polynrethanes [246], polyaniline [247], flnorinated polymer films [248], poly(o-tolnidine) [249], polyetherimide and poly benzimidazole [250], polyfnllerene palladinm [251], imidazole-containing imidazolylethyl maleamic acid-octadecyl vinyl ether copolymer [252], polyphenylene vinylene ether [253], thiophene oligomers [254], flnorinated styrene-isoprene derivative of a methyl methacrylate-hydroxyethyl methacrylate copolymer [255], polythiophene [256], dibromoalkane-hexaflnorisopropylidene diphenol and bisphenol A [257], and geopolymers [258]. 

When MA reacts with ammonia, a primary or a secondary amine, acylation occurs resulting in formation of an amide derivative. This half-amide derivative is called maleamic acid 108. When one of the R groups in 108 is aryl, often the product is referred to as a maleanilic acid. 

Although no geometries have been indicated in most of these synthetic works, it is known that amines isomerize maleic acid derivatives to the thermodynamically more stable fumaric acid derivatives. Furthermore, cycliz-ation to imides is much more easily obtained with succinic acid and phthalic acid/ It may be concluded, therefore, that low yields of cyclization in maleamic acid is not so much due to lack of reactivity as to the formation of less reactive fumaramic derivative by isomerization. 

Michael addition reactions alcohols with maleates, 46 with fumarates, 63 MA with acetylacetone, 235 MA derivatives, 65, 66 in maleamic acid cyclization, 83 with maleates, 63 maleates with thiols, 506 maleic anhydride, 65, 229 maleimides with amines, 512 Mitsubishi process, MA production, 29... 

Unlike 2,1-benzisoxazoles, 2,1-benzisothiazole (and its 5-methoxy-derivative) does not undergo the Diels-Alder reaction. 3-Amino-2,l-benzisothiazole (118 R=H) reacts with maleic anhydride in boiling benzene to yield simply the maleamic acid (119 R = H). 3-Methyl(and ethyl)amino-2,l-benzisothiazole (118 R = Me or Et), on the other hand, produce the thioamide (121), possibly by way of the intermediate (non-isolable) Diels-Alder adduct (120). ... 

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