Tricarboxylic acid and

Papaverinic acid, CieHjjO N. HjO, crystallises in small tablets, m.p. 233°. It is dibasic, readily forms an anhydride, furnishes an oxime and a phenylhydrazone, contains two methoxyl groups, and on oxidation yields veratric and pyridine-2 3 4-tricarboxylic acids, and hence is represented by the following formula —... 

The aglycone of betaniu, the red-violet pigment of the beet (Beta vulgaris var. rubra), known as betanidin, has recently been shown to have the structure depicted in structural formula 113.170,282 Betanidin had previously been reported by Piattelli and Minale to contain a dopachrome unit in its structure and consequently would have been formulated as 114.109 The Italian workers obtained pyrrole-2,3,5-tricarboxylic acid and pyridine-2,4,6-tricarboxylic acid on permanganate oxidation of betanidin and they also prepared a semi-carbazone of the pigment, the absorption spectrum of which showed the pH dependency expected for an aminochrome semicarbazone.169... 

Ethane-tricarboxylic acid and derivs 6 El 52—El 54 ethane-tricarboxylic acid triazide 6 El52 ethane-1,1,1-tris (hydroxymethyl) trinitrate (MtrT) 6 El 52—El 54... 

Carbonation of lithiofurans is a useful method for obtaining these compounds. Furan-2-carboxylic acid (pKa 3.15) is a stronger acid than the 3-carboxylic acid (pKa 4.0) because of the inductive effect of the ring oxygen, and both are stronger than benzoic acid. Furancarboxylic acids can be decarboxylated by the copper-quinoline method or merely by heating. The 2-carboxylic acids are more easily decarboxylated than the 3-isomers, so furan-3-carboxylic acid can be obtained by stepwise decarboxylation of the tetracarboxylic acid via the 2,3,4-tricarboxylic acid and the 3,4-dicarboxylic acid. A more convenient source of the 3-carboxylic acid is by partial hydrolysis and decarboxylation of the readily available diethyl furan-3,4-dicarboxylate (71S545). 

HPCA is also sometimes formulated with tricarboxylic acid and TTA to provide an All Organic Closed-Loop Program as an alternative to nitrite-based treatments. 

Reddish-brown plates from water. C4iH5502oN9Fe-4H20. Gives tea-colored solutions with amM=3.74 at 4400 A. The iron is more tightly bound than in ferrichrome log Ks 32. Ferrichrome A is a tricarboxylic acid and on removal of iron with cyanide and Na2S2C>4, deferriferrichrome A is seen to acquire three new acid groups with pKa 9 (hydroxamates). 

Organic networks are also capable of exhibiting interpenetration. Figure 6 illustrates the threefold interpenetration that occurs in the cocrystal formed between trimesic acid (benzene-1,3,5-tricarboxylic acid) and bipy. This structure exhibits interpenetration in 2D to form a novel carpet-like architecture.54 The non-interpene-trated form of this compound has not yet been isolated. 

Numbered peaks refer to the carbon chain length of (no prefix) dicarboxylic acids, (T prefix) tricarboxylic acids and (0 prefix) oxirane acids. X identifies 1,2-epoxy-1,1,2,3-propanetetracarboxylic acid. 

Some acids not found in oxidation products of lignins, land plants, and marine sediments were found in the oxidation products of coals. Among these were phenolic di- and tricarboxylic acids and hydroxy-naphthalenecarboxylic acids. From some soil fulvic and humic acids, phenolic poly carboxylic acids have been found in the oxidation products together with considerable amounts of fatty acids. Therefore, phenolic esters of fatty acids are considered to be present in these soil acids (6, 27). However, little or no fatty acids were observed in the coal oxidation products. 

Chloroformyl(naphthalic anhydride), a derivative of naphthalene-1,4,5-tricarboxylic acid, and the acid itself were involved in preparing bis(naphthalic anhydrides) containing ester and amide groups (Scheme 26) ... 

Pyrindicin.—The pattern of C n.m.r. signal enhancement observed on incorporation of [1- C]- and [2- C]-acetate and [l- C]propionate into pyrindicin (9) in Streptomyces griseoflavus var. pyrindicus indicates that the metabolite is formed from five acetate units and one propionate unit, as shown in (9). Some labelling by acetate of the propionate unit was observed, which was interpreted as being the result of metabolism via both the tricarboxylic acid and glyoxalate cycles. 

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. ... 

Melt condensation of l,4, na thalei tricarboxylic acid and aromatic diacetamides yielded [122] dianhydrides containing amide groups. Scheme 28. 

Preferential esterification. Startg. tricarboxylic acid and Amberlyst 15 in methanol stirred at room temp, for 10 h monomethyl ester. Y 80%. a,p-Unsatd. and ar. carboxyl groups were left unaffected the method failed with higher alcohols (/-PrOH /-BuOH). Under these mild conditions, a-epimerization, c/5-tra 5-rearrangement, and transesterification (of ethyl esters) are avoided, and keto and olefinic groups remain intact. F.e. inch methyl esters of bile acids s. M. Petrini et al., Synth. Commun. 18, 847-53 (1988). 

Secondary products derived from the acids of the tricarboxylic acid, and glyoxylic acid cycles are built in microorganisms, plants, and animals. 

Mukkada AJ (1977) Tricarboxylic acid and glyoxylate cycles in the Leishmania. Acta Trop 34 167-175... 

Organic acids are hydrocarbons that are characterized by their carboxylate function (COOH). Their hydrocarbon structure can vary considerably from aliphatic to aromatic, saturated to unsaturated, and straight chain to branched. Other variations in structure include varying chain lengths, multiple carboxylate groups (e.g., di- or tricarboxylic acids), and presence of hydroxyl- and ketofunctions. Organic acids with different molecular structures obviously differ in their physical and chemical properties. 

In case C where jc = 1 the acid will be 1,2,4-butane tricarboxylic acid and when x = 2 the acid will be 1,3,5,6-hexane tetracarboxylic acid if the 1,2- groups are linked head-to-tail, and the 1,3,4,6- isomer if linked head-to-head. 

Effective routes to buta-l,3-diene-l,l,4-tricarboxylic acids and to derivatives of (2Z,4Z)-3-methylhexa-2,4-dienedioic acid have been reported. Five different 6-substituted (Z)-2-en-4-ynoic acids have been synthesized, mainly by the coupling of methyl (Z)-3-iodopropenoate and the appropriate cuprous acetylide followed by hydrolysis of the ester. A synthesis of racemic integerrinecic acid (31), in five steps from ethyl acrylate, is reported. ... 

By using IR, Shafizadeh and co-workers have identified phthalic (1,2-benzene dicar-boxylic acid), isophthalic (1, 3), hemimellitic (1,2, 3), trimellitic (1, 2,4), prehnitic (1, 2,3,4), mellophanic (1,2,3,5), pyromellitic (1,2,4,5), benzene penta and hexa carboxylic acids [32]. Hemimellitic and trimellitic acids were formed approximately at 2 3 ratio and prehnitic, mellophanic and pyromellitic acid approximately at 2 1 1 ratio. At the lower HTTs, in addition to the above compounds, lower amounts of monohydroxy benzene dicarboxylic acid, monohydroxy benzene tricarboxylic acid, and monohydroxy benzene tetracarboxylic acid have been detected, as well. 

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