A-Dicarboxylic acids

To make 351C we need to convert a dicarboxylic acid into its half amide. How might we do this ... 

Write equations showing how 3 methyl 1 5 pentanediol could be prepared from a dicarboxylic acid or a diester I... 

Separate ionization constants designated Ki and K2 respectively characterize the two successive ionization steps of a dicarboxylic acid... 

Polyesters are a second class of condensation polymers and the principles behind their synthesis parallel those of polyamides Ester formation between the functional groups of a dicarboxylic acid and a diol... 

Condensation of polyhydroxy compounds with polybasic acids, e.g. a glycol with a dicarboxylic acid ... 

Alcoholysis of the acid chloride of a dicarboxylic acid with a polyhydroxy alcohol ... 

Plasticizers can be classified according to their chemical nature. The most important classes of plasticizers used in rubber adhesives are phthalates, polymeric plasticizers, and esters. The group phthalate plasticizers constitutes the biggest and most widely used plasticizers. The linear alkyl phthalates impart improved low-temperature performance and have reduced volatility. Most of the polymeric plasticizers are saturated polyesters obtained by reaction of a diol with a dicarboxylic acid. The most common diols are propanediol, 1,3- and 1,4-butanediol, and 1,6-hexanediol. Adipic, phthalic and sebacic acids are common carboxylic acids used in the manufacture of polymeric plasticizers. Some poly-hydroxybutyrates are used in rubber adhesive formulations. Both the molecular weight and the chemical nature determine the performance of the polymeric plasticizers. Increasing the molecular weight reduces the volatility of the plasticizer but reduces the plasticizing efficiency and low-temperature properties. Typical esters used as plasticizers are n-butyl acetate and cellulose acetobutyrate. 

In the endoplasmic reticulum of eukaryotic cells, the oxidation of the terminal carbon of a normal fatty acid—a process termed ch-oxidation—can lead to the synthesis of small amounts of dicarboxylic acids (Figure 24.27). Cytochrome P-450, a monooxygenase enzyme that requires NADPH as a coenzyme and uses O, as a substrate, places a hydroxyl group at the terminal carbon. Subsequent oxidation to a carboxyl group produces a dicarboxylic acid. Either end can form an ester linkage to CoA and be subjected to /3-oxidation, producing a... 

With a mixed anhydride two different arylketones may be formed. Reaction of a cyclic anhydride of a dicarboxylic acid, e.g. succinic anhydride, leads to formation of an arylketo acid. ... 

Semmler and Risse have studied the oxidation of cedrene by means of ozone. They obtained the keto-acid, Cj Hj Oj, which on further oxidation either by means of bromine or nitric acid yields a dicarboxylic acid. 

Polyesters can be produced by an esterification of a dicarboxylic acid and a diol, a transesterification of an ester of a dicarboxylic acid and a diol, or by the reaction between an acid dichloride and a diol. 

Polyamides are produced by the reaction between a dicarboxylic acid and a diamine (e.g., nylon 66), ring openings of a lactam, (e.g., nylon 6) or by the polymerization of w-amino acids (e.g., nylon 11). The production of some important nylons is discussed in the following sections. 

Vlalic acid, C.jHgO, has been isolated from apples. Because this compound reacts wnth 2 molar equivalents of base, it is a dicarboxylic acid. 

If a more powerful oxidizing agent such as warm dilute HN03 is used, an aldose is oxidized to a dicarboxylic acid, called an aldaric acid. Both the —CHO group at Cl and the terminal -CH2OH group are oxidized in this reaction. 

Maleic acid and fumaric acid are the cis- and trans- isomers, respectively, of QH COOH) a dicarboxylic acid. Draw and label their structures. 

Consider what happens when an alcohol with two —OH groups, HO—R—OH, reacts with a dicarboxylic acid, HOOC—R —COOH. In this case the ester formed still has a reactive group at both ends of the molecule. 

Linear step-growth polymerizations require exceptionally pure monomers in order to ensure 1 1 stoichiometry for mutually reactive functional groups. For example, the synthesis of high-molecular-weight polyamides requires a 1 1 molar ratio of a dicarboxylic acid and a diamine. In many commercial processes, the polymerization process is designed to ensure perfect functional group stoichiometry. For example, commercial polyesterification processes often utilize dimethyl terephthalate (DMT) in the presence of excess ethylene glycol (EG) to form the stoichiometric precursor bis(hydroxyethyl)terephthalate (BHET) in situ. 

A closely related reaction is equilibration of a dicarboxylic acid and its diester to produce monoesters ... 

N-Substituted amides can be prepared by direct attack of isocyanates on aromatic rings.The R group may be alkyl or aryl, but if the latter, dimers and trimers are also obtained. Isothiocyanates similarly give thioamides. The reaction has been carried out intramolecularly both with aralkyl isothiocyanates and acyl isothiocyanates.In the latter case, the product is easily hydrolyzable to a dicarboxylic acid this is a way of putting a carboxyl group on a ring ortho to one already there (34 is... 

Three other portions of the molecule which do not fit the polyketide combination pattern (Scheme 7B a,f,n) can be also explained by assuming they are derived from a dicarboxylic acid such as 3-hydroxy-3-methylglutaric acid (Scheme 8b). If that is the case, brevetoxins are a new type of mbced polyketides which are formed by condensation on both ends of dicarboxylic acids (Scheme 8c). In order to prove further the hypothesis, feeding experiments with such putative precursors as succinate, acetoacetate, and propionate are in progress. 

This is an typical example of a dicarboxylic acid in that C-C cleavage is the only route for oxidation. No study of the Co(III) oxidation has been made although it is highly probable that reaction would proceed through an oxalate complex. The thermal decomposition of Co(Ox)3 has been shown to be a first-order process and probably involves an internal redox reaction, viz. 

Polymerisation of a diol with a dicarboxylic acid is exemplified by the production of a polyester from ethylene glycol and terephthalic acid either by direct esterification or by a catalysed ester-interchange reaction. The resulting polyester Terylene) is used for the manufacture of fibres and fabrics, and has high tensile strength and resiliency its structure is probably ... 

Branched polyesters contain oxalkylated primary fatty amines or oxalkyl-ated polyamines together with at least trivalent oxalkylated alkanol that is responsible for branching. The condensation is achieved with a dicarboxylic acid or a dicarboxylic acid anhydride [216]. In this way, branched polyoxyalkylene mixed polyesters are formed. Suitable solvents are water or organic solvents, such as methanol, isopropanol, butanol, or aromatic hydrocarbons (e.g., toluene, xylene). 

Cationic condensation products, namely, the reaction products of a dicarboxylic acid or an ester or acid halide thereof and an aminoalkylamine, that are quatemized are recommended for breaking cmde oil emulsions from fireflooding [365],... 

If the carboxylic acid has two carboxyl functional groups (a dicarboxylic acid) and if the alcohol has two hydroxyl functional groups (a diol), a polyester will result nHOOC—R—COOH + nHO—R —OH —> +OOC—R—COO—R +n + nH20. 

Esterification of a dicarboxylic acid such as terephthalic acid via the diimidazolides with diols readily leads to the corresponding polyesters.[12]... 

Polyesters form via a condensation reaction between a dicarboxylic acid and a dialcohol to create an ester linkage, as shown in Fig. 24.1. By far, the two most common polyesters are polyethylene terephthalate and polybutylene terephthalate, the chemical structures of which are shown in Fig. 24.2. These two polymers differ from one another by the length... 

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