Dicarboxylic acid anhydrides imides

Procedures have been reported to convert 67 into the corresponding imide (74) (73USP3736299), dicarboxylic acid (75), anhydride (76), and a variety of acid/esters (77) and diesters (78) (75USP3915974). Chromic acid oxidation of 2,3-dichloroquinoxaline has also been reported as a route to 75 (58RTC842). 

Dicarboxylic acid imides from dicarboxylic acid anhydrides... 

Subst. dicarboxylic acid imides from anhydrides GO/ ... 

Dicarboxylic acid imides e.g. (189) were prepared in high yield by cyclization of carboxylic acid amides (190) with trifluoroacetic acid this technique avoided dehydration to the nitrile (191), which was easily achieved with acetic anhydride. This work is part of a total synthesis of maleimycin. ... 

Diacylamines from carboxylic acid anhydrides, and dicarboxylic acid imides from dicarboxylic acid anhydrides... 

Pyrrole is one of the most prominent heterocycles, having been known for more than 150 years, and it is the structural skeleton of several natural products, synthetic pharmaceuticals, and electrically conducting materials. A simple access to the pyrrole ring system involves the conversion of cyclic anhydrides into five-membered imides. Mortoni and coworkers have described the conversion of 2-methylquinoline-3,4-dicarboxylic acid anhydride to a quinoline-3,4-dicarboximide library by treatment of the anhydride with a diverse set of primary amines under microwave conditions (Scheme 6.180) [341]. The authors studied a range of different conditions, including dry media protocols (see Section 4.1) whereby the starting materials were adsorbed onto an inorganic support and then irradiated with microwaves. For the transforma-... 

Azo compounds like esters or imides of azo dicarboxylic acid act as reactive dienophiles in normal electron demand hetero Diels-Alder reactions due to the strong activation caused by two electron-withdrawing moieties. In the last years, considerable attention has focused on alkyl and phenyl derivatives of 1,2,4-tria-zoline-3,5-diones since their cycloadditions to chiral dienes proceed with often excellent facial selectivities. Thus, when reacting an oxapropellane derived diene with N -methyltriazolinedione, Paquette et al. obtained the cycloadduct as single diastereomer, but both maleic anhydride and N-phenyl maleimide were distinctly less reactive and turned out to undergo cycloadditions with poor selectivities [289]. 

When Af-substituted imides of cyclopropane-c/j-l,2-dicarboxylic acid were reacted with sodium borohydride in methanol the product was the corresponding hydroxyamide in excellent yield, e.g. formation of 1. Similar primary reactions occurred on reaction of a derivative of cyclopropane-cH-l,2-dicarboxylic anhydride with bis(l,2-dimethylpropyl)borane (disiamylborane) in diethyl ether and also on reaction of 7/,A -disubstituted cyclopropanecar-boxamides with sodium bis(2-methoxyethoxy)aluminum hydride. ... 

Good yields of a pyridazine (rather than the bishydrazide) are obtained from a dicarboxylic acid by first converting the latter into its anhydride by heating with acetic anhydride, and then adding a hydrazine. A related pyridine diester is cyclized vnth hydrazine hydrate [2733] (sometimes with hydrochloric acid present [3918]) at ambient tem()erature to the dihydrazide, which may be converted to the dione by heating with hydrazine [2733], and to the imide on acidification with acetic acid. The pyridazinedione may also be prepared from the imide (80J) by heating with hydrazine hydrate [2797]. 

Kricheldorf has reported the synthesis of lyotropic poly(amide-imide)s and poly(benzoxazole-amide)s. These were prepared by the polycondensation of N,N-bis(trimethylsilyl)-p-phenylenediamine or N,AT -bis(trimethylsilyl)-3,3 -dim-ethylbenzidine with the diacyl chloride of trimellitimide of p-aminobenzoic acid, or the imide formed from p-amino benzoic acid and terephthalic acid. Lyotropic behaviour was observed in cone, sulphuric acid solution [38]. A series of thermotropic poly(imide-amide)s was prepared based on trimellitimides formed from trimellitic anhydride and an a, -bis(4-aminophenoxy) alkane with carbon chain lengths 9-12. Melting points were in the range 250-300 °C. They formed smectic A phases and tended to degrade around the isotropisation temperatures (around 350 °C). Pendant methyl groups or occupied meta- groups tended to prevent mesophase formation [39]. Novel LC poly(imide-amides) have also been synthesised from new diamine spacers derived from linear diaminoalkanes and 4-nitrophthalic anhydride. A smectic and nematic phase were observed when 4,4 -biphenyl dicarboxylic acid was used as co-monomer [40]. 

Table 23 demonstrates the mesogenicity of polymers containing biphenylene-S j -tetracarboxylic imide. A comparison of series 9 and 10 in the table shows that replacement of pyromellitic dianhydride with BPTA in a copolymer with two moles of m-aminophenol and an aromatic diacid does not lead to mesogenic polymers. The assignment of an MI score of 4 compared to 2 for pyromellitic anhydride does however raise the MI as far as the borderline condition of MI=9.5 when 2,6-naphthalene dicarboxylic acid is the co-monomer. 

Catalytic hydrogenation of the imide 24 (R = H) over palladium on charcoal results in partial reduction of the pyrazine ring to give the tetrahydro compound 37. The anomalous products 31 and 32 from the reaction of the anhydride of pyrazine-2,3-dicarboxylic acid and hydrazine were presumed to have been formed by reduction of the pyrazine ring by diimide. This could have been formed in situ by oxidation of hydrazine... 

PAIs can be prepared by the condensation of a monoanhydride of a tricarboxylic acid and a primary diamine. Further PAI can be prepared by tbe reaction of dicarboxylic acid chlorides and diamines. Here, either the diamines or diacid halides already contain imide linkages, or mutatis mutandis, amide linkages. Classical PAI are usually obtained by reacting equimolar amounts of trimellitic acid hahde anhydride and a diamine. ... 

A dicarboxylic acid bearing two preformed imide rings, namely 4,4 -bis(trimellitimido)-4 -methoxytri-phenylamine, has been prepared by the condensation of 4,4 -diamino-4 -methoxytriphenylamine and trimellitic anhydride [105,106]. The synthesis is shown in Figure 14.12. 

Another important group are the polyamide imides and polyimides. The substitution of tricarboxylic acid anhydride for dicarboxylic acids during synthesis results in thermally more stable polyamide imides. The polycondensation reaction proceeds in two steps, with the solution of the intermediate polycarboxylic acid used in applications where the final product can be generated by a thermal or baking process. Uses include heat-resistant wire and cable coatings. The basic synthesis of polyamide imides is as follows ... 

There are cyclic esters (known as lactones), cyclic amides (known as lactams), cyclic anhydrides, and cyclic imides. The structures for these derivatives are presented in Chapter 20, Section 20.6.5. The chemical reactions associated with derivatives of dicarboxylic acids are discussed in Chapter 20 as well. 

Imides are formed by the reaction of amides with other acid derivatives. Cyclic anhydrides and cyclic imides can be prepared from dicarboxylic acids or acid dichlorides. 

Polyanhydride structures can be modified by the addition of aminoacids, linked via imide bonds at the amino terminus, so that the carboxylic acid terminus remains available for the interaction with acetic anhydride [459]. These poly(anhydride-imides) degrade in a similar way as the simple polyanhydride polymers. Other modifications that can take place are copolymers linked with esters. In that way, the polymer contains two types of hydrolytically cleavable bonds. In the presence of water, both types of bonds are hydrolyzed, releasing the dicarboxylic acid and the ester [460]. An example of a poly(anhydride-ester) with application in the medicinal field includes sebacic acid and salicylic acid, a therapeutically useful compound. The release of sebacic acid in the body opens up a variety of potential applications. 

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