Dicarboxylic Acids and Derivatives

Sulfomalonic acid is too unstable for isolation, but some related compounds are known. Cyanoacetamide did not react with chlorosulfonic acid, although the anilide 117 is claimed to react with the reagent in chloroform solution to form the disulfonic acid 118 in which sulfonation has occurred exclusively at the methylene hydrogens (Equation 46). 

The reactivity of the methylene hydrogen atoms towards the reagent apparently increased when the phenyl moiety of 117 was substituted by tolyl and naphthyl radicals which was suggested to be associated with their electronegativity. The proposed structure of the disulfonic acid 118 seems unlikely, since cyanoacetamide is inert towards chlorosulfonic acid while anilides are readily sulfonated by the reagent in the aryl ring (see Chapter 4, p 103). 

In view of these results, it is probable that at least one of the sulfonic acid groups enters the aromatic nucleus giving the isomeric disulfonic acid 119 as the more likely structure for the product (Equation 46). 

The sulfonation of malondianilide by chlorosulfonic acid (two equivalents) was also claimed to occur exclusively at the methylene hydrogens, but this is probably incorrect, since the compound is known to react with excess reagent by sulfonation of the phenyl rings giving the 4,4 -disulfonyl chloride. The structure proposed for the product from the action of chlorosulfonic acid on methyl malondiarylamides is also unlikely since at least one of the sulfonic acid groups probably enters the aryl ring. 

A solution of chlorosulfonic acid in 1,2-dichloroethane reacts with citric (2-ketopropan-1,2,3-tricarboxylic) acid 120 to give the disulfate ester 121, which on treatment with absolute alcohol at 25 °C affords 2-ketobutanedioic acid 122 (94-96 yield) (Equation 47).  

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An enormous variety of olefinic types have been found to undergo such solid-state (2 + 2) photocyclodimerizations. These include cinnamic acids (128,132) derivatives of cinnamic acids such as esters (133) and amides (134) styrene derivatives (135) stilbenes (136) aliphatic mono- (137), di- (138), and triene (139) dicarboxylic acids and derivatives 1,4-diarylbutadienes (140) and their vinylogs (141), benzylidene acetones (142) and benzylidene acetophenones (143) ... 

Benzo[c] cinnoline aldehydes are as yet unknown. The 2- and 3-acetyl derivatives have been prepared, but the majority of known compounds relevant to this section are mono- and dicarboxylic acid derivatives. These include the 2-, - - 3-, ° and 4. - o2.J55,i57 monoacids and esters, the lactone of 10-hydroxybenzo[c]cinnoline-l-carboxylic acid, some halogeno- and methyl-substituted 2- and 4. carboxylic acids, and the 2,9-, 3,8-, - - and 4,7- dicarboxylic acids and derivatives. These compounds have been obtained by ring synthesis, or, in the case of 2-methylbenzo[c]dnnoline-9-carboxylic acid, by side-chain oxidation, " rather than by the introduction of substituents into benzo[c] cinnoline. Benzo[c]cinnoline-l-carbonitrile has been prepared, albeit in low... 

Table 8.3 Aromatic dicarboxylic acids and derivatives used for polyester polyol synthesis ...

The most common reaction of this type is the cyclization of various derivatives of hydrazine and substituted hydrazines with pyridine o-dicarboxylic acids and related compounds. Reactions in which the acid derivative reacts directly with the hydrazine are dealt with as [4 + 2] reactions in Section 2.15.10.6.1. 

The degradation of more complex substances can be regarded as another route to pteridine derivatives. Already in 1895 tolualloxazine was oxidized by alkaline permanganate to lumazine-6,7-dicarboxylic acid, and further heating led in a stepwise decarboxylation to lumazine (3) (1895CB1970). 

Reaction of -picoline over degassed Raney nickel was found to give 5,5 -dimethyl-2,2 -bipyridine (5), the structure of which was established by its synthesis from 2-bromo-5-methylpyridine. Oxidation of this dimethyl-2,2 -bipyridine, and similar oxidation of the diethyl-2,2 -bipyridine derived from 3-ethylpyridinc, gave the corresponding dicarboxylic acid and the same acid was produced by the action of degassed Raney nickel on sodium nicotinate (in water) or on ethyl nicotinate. These transformations established the 5,5 -substitution pattern for three 2,2 -bipyridines derived from 3-substituted pyridines but such evidence is not available for the biaryls... 

Activating agents, such as trifluoroacetic anhydride 1,1 -carbonyldiimidazolc carbodiimides sulfonyl, tosyl, and picryl chlorides and a range of phosphorus derivatives can promote direct solution reactions between dicarboxylic acids and diols or diphenols in mild conditions. The activating agents are consumed during the reaction and, therefore, do not act as catalysts. These so-called direct polycondensation or activation polycondensation reactions proceed via the in situ transformation of one of the reactants, generally the carboxylic acid, into a more... 

Diselosed is a proeess for the simultaneous production of dicarboxylic acids and diamines from a) polymers based on polyamides of dicarboxylic acids or their derivatives with diamines or b) compositions containing essentially such polymers. It involves treating these polymers or compounds with a base in alcoholic medium and subsequently converting the resulting dicarboxylate salts electrochemically into the corresponding dicarboxylic acids and bases. 

J. Rontani, C. Aubert, Trimethylsilyl transfer during electron ionization mass spectral fragmen tation of some or hydroxycarboxylic and to dicarboxylic acid trimethylsilyl derivatives and the effect of chain length, Rapid Commun. Mass Spectrom., 18, 1889 1895 (2004). 

There has in the past been some confusion in the use of the term alkyd, which is said to have been derived from alcohol plus acid. The definition offered by Kienle [1], discussed later, is broad enough to include all polyesters derived essentially from diols and dicarboxylic acids, and consequently linear polyesters were initially included in this class of polymer. On the other hand, Bjorksten et al. [2], in their 1956 compilation of published information about polyesters, restrict the term polyester to the polycondensation products of dicarboxylic acids with dihydroxy alcohols, and say that this definition does not include materials commonly known as alkyds . At the present time, there are still problems of nomenclature in the fibre field arising from the use of polyester as a generic term to cover fibres containing only a very restricted range of chemical groups. 

The 7-azabicyclo[2.2.1]heptene derivative (57) decomposes in hot aqueous sodium carbonate solution to give A-benzylpyrrole-3,4-dicarboxylic acid and, presumably, ethylene. Furan-3,4-dicarboxylic acid derivatives are formed analogously on heating the 7-oxabicyclo-[2.2.1]heptene diesters (58). The only thermal decomposition of a... 

Polyarylates (PAr) are wholly aromatic polyesters derived from aromatic dicarboxylic acids and diphenols or their derivatives. They are amorphous in nature with good injection moldability. Figure 7 shows the typical formula structure of PAr. 

Hi) Carboxylic acids and derivatives. The haloform reaction on thienyl methyl ketones leads to thiophenecarboxylic acids, which can be treated with Raney nickel to produce the open-chain acids. This method has been used for the five-carbon homologation of carboxylic acids and to produce dicarboxylic acids (Scheme 51). Long-chain carboxylic acids may also be prepared by using dicarboxylic acid derivatives for the acylation of thiophenes (Scheme 52). In the synthesis of Queen substance, the precursor (213) has been generated by Raney nickel desulfurization of the appropriate thiophene-2-acetic acid derivative (79T329). 

VITAMINS - BIOTIN] (Vol 25) - [MAT. ETC ANHYDRIDE, MALEIC ACID AND FUMARIC ACID] (Vol 15) - [MAIONIC ACID AND DERIVATIVES] (Vol 15) - [MICROBIALTRANSFORMATIONS] (Voll6) -as food additive [FOOD ADDITIVES] (Vol 11) -fortifying roan [PAPERMAKING ADDITIVES] (Vol 18) -hydrahonof [HYDROXY DICARBOXYLIC ACIDS] (Vol 13) -m meat processing [MEAT PRODUCTS] (Vol 16)... 

A number of studies have reported the formation of carboxonium-centered distonic dications. These systems include diprotonated diketones, diproto-nated dicarboxylic acids, their derivatives, and others. A wide variety of mixed dications have also been reported such as ammonium-carboxonium dications, oxonium-carboxonium dications, acyl-carboxonium dications, and other species. Many of these carboxonium-centered dications exhibit properties indicative of distonic superelectrophiles. 

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