Esters and salts

6 Carboxylic adds another set of CHO compounds containing C=0 groups 

Some members of this series with larger numbers of carbon atoms are called fatty acids . This is because some form part of esters with glycerol, and their compounds are present in fats. Stearic acid, CH3(CH2)i6COOH, is found in animal and vegetable fats. Arachidic acid, CH3(CH2)lgCOOH, is found in peanut oil. 

Like all acids, the carboxylic acids will form salts with alkalis. With sodium hydroxide ethanoic acid will form sodium ethanoate (or sodium acetate). Salts of 

With an alcohol the salts are known by the special name of esters . 

Acid + alcohol — esters + water CH3 CO OH + C2H5OH ch3 CO oc2h5 + h2o Ethanoic acid + ethanol — ethyl ethanoate + water 

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H02C(CH2)2C02H. Colourless prisms m.p. 182 C, b.p. 235°C. Occurs in amber, algae, lichens, sugar cane, beets and other plants, and is formed during the fermentation of sugar, tartrates, malates and other substances by a variety of yeasts, moulds and bacteria. Manufactured by the catalytic reduction of maleic acid or by heating 1,2-dicyanoethane with acids or alkalis. Forms an anhydride when heated at 235°C. Forms both acid and neutral salts and esters. Used in the manufacture of succinic anhydride and of polyesters with polyols. 

The cyclization of -halocarbonyl compounds is carried out with a great variety of reactants including thioamides, thioureas, their mono- or disubstituted derivatives, and salts and esters of monothiocar-bamic acid, leading to variously substituted thiazoles. 

Reaction wifli Salts and Esters of Thiocarbamic Acid 2-Hydroxythiazoles and Derivatives... 

Reaction witii Salts and Esters of Ditiiiocarbamic Add 2 Mercaptothiazole Derivatives and 2-Thiazolyl Sulfides... 

This type of synthesis, which was investigated by Cook and Heilbron (323) and Takahashi (393, 394) between 1947 and 1953, gives 5-aminothiazoles variously substituted in the 2-position by reacting an aminonitrile with salts and esters of dithioacids, carbon disulfide, carbon oxysulfide, and isothiocyanates under exceptionally mild conditions. 

Salts and Esters of Dithioadds S-Aminothiazole Derivatives and Related Condensations... 

The fermentation-derived food-grade product is sold in 50, 80, and 88% concentrations the other grades are available in 50 and 88% concentrations. The food-grade product meets the Vood Chemicals Codex III and the pharmaceutical grade meets the FCC and the United States Pharmacopoeia XK specifications (7). Other lactic acid derivatives such as salts and esters are also available in weU-estabhshed product specifications. Standard analytical methods such as titration and Hquid chromatography can be used to determine lactic acid, and other gravimetric and specific tests are used to detect impurities for the product specifications. A standard titration method neutralizes the acid with sodium hydroxide and then back-titrates the acid. An older standard quantitative method for determination of lactic acid was based on oxidation by potassium permanganate to acetaldehyde, which is absorbed in sodium bisulfite and titrated iodometricaHy. 

The reactions of oxaUc acid, including the formation of normal and acid salts and esters, are typical of the dicarboxyhc acids class. OxaUc acid, however, does not form an anhydride. 

Reactions of the Carboxyl Groups. Carboxyl groups in the ortho position spontaneously form a strainless ftve-membered ring when heated to give anhydrides as shown for (8). Salts and esters (4) are readily formed as shown for (4) and (5), respectively. 

In the United States all other processes have been completely phased out and virtually all benzoic acid is manufactured by the continuous hquid-phase air oxidation of toluene. In the late 1950s and the early 1960s both Dow Chemical and Snia Viscosa constmcted faciUties for Hquid-phase toluene oxidation because of large requirements for benzoic acid in the production of phenol and caprolactam. Benzoic acid, its salts, and esters are very useful and find appHcation in medicinals, food and industrial preservatives, cosmetics, resins, plasticizers, dyestuffs, and fibers. 

Carbon dioxide, the final oxidation product of carbon, is not very reactive at ordinary temperatures. However, in water solution it forms carbonic acid [463-79-6] H2CO2, which forms salts and esters through the typical reactions of a weak acid. The first ionization constant is 3.5 x 10 at 291 K the second is 4.4 x 10 at 298 K. The pH of saturated carbon dioxide solutions varies from 3.7 at 101 kPa (1 atm) to 3.2 at 2,370 kPa (23.4 atm). A soHd hydrate [27592-78-5] 8H20, separates from aqueous solutions of carbon dioxide that are chilled at elevated pressures. 

Chlorosulfuric acid is a strong acid containing a relatively weak sulfur—chlorine bond. Many salts and esters of chlorosulfuric acid are known, most of them are relatively unstable or hydrolyze readily in moist air. 

Free naphthenic acids are corrosive and are mainly used as their salts and esters. The sodium salts are emulsifying agents for preparing agricultural insecticides, additives for cutting oils, and emulsion breakers in the oil industry. 

N = N in diazo compds, hydrazoic acid, its salts and esters... 

Polymer films can be made antistatic with a-sulfonated fatty acid salts and esters [94]. For example, an antistatic additive for polypropylene manufacture can be prepared from potassium methyl a-sulfopalmitate, styrene oligomer, and 2-propanol [95]. The treatment of synthetic fibers and fabrics with a-sulfo-... 

PCP was widely applied by the leather industry before the 1990s for improving the biocidal activity of raw hides and skins. Due to the risk of transformation into dioxin during burning, the use of PCP and its salts and esters in leather manufacturing is not allowed in the EU according to EU Regulation 1997/2006 (Annex XVII) [12],... 

Some member states in the EU like Germany, Austria and Denmark have in addition implemented stricter legislation than EU and restrict the marketing of leather products containing PCP and its salt and esters. 

Contact between the salt and ester caused violent explosions on several occasions. (Methyl perchlorate may have been formed). 

Numerous preparative methods have been reported for these acids and their salts and ester derivatives.1 4 Dithiophosphoric acids are accessible from the reaction of phosphorus pentasulfide with alcohols or phenols (Equation 18). Dithiophosphinic acids can be prepared from thiophosphinic chlorides and sodium hydrosulfide (Equation 19), although the phenyl derivative is better prepared using a modified Friedel-Crafts reaction in which phosphorus pentasulfide is reacted with benzene in the presence of anhydrous aluminium trichloride (Equation 20). 

Erickson, L. E. Proton Magnetic Resonance Spectra of Substituted Succinic Anhydrides, Acids, Salts and Esters. J. Am. Chem. Soc. 87, 1867 (1965). 

In asymmetric hydrogenation of olefins, the overwhelming majority of the papers and patents deal with hydrogenation of enamides or other appropriately substituted prochiral olefins. The reason is very simple hydrogenation of olefins with no coordination ability other than provided by the C=C double bond, usually gives racemic products. This is a common observation both in non-aqueous and aqueous systems. The most frequently used substrates are shown in Scheme 3.6. These are the same compounds which are used for similar studies in organic solvents salts and esters of Z-a-acetamido-cinnamic, a-acetamidoacrylic and itaconic (methylenesuccinic) acids, and related prochiral substrates. The free acids and the methyl esters usually show appreciable solubility in water only at higher temperatures, while in most cases the alkali metal salts are well soluble. 

D salts and esters 4,6-Dinitro-o-cresol and salts Acrolein... 

Liquid oral antidiarrhoeals or any other dosage form for paediatric use containing diphenoxylate or atropine or belladonna including their salts and esters or metabolites, hyoscyamine or their extracts or their alkaloids. 

Dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), and their salts and esters are compounds of interest as herbicides used for the destruction of weeds (Figure 56-1). They have been assigned toxicity ratings of 4 or 3, respectively, which place the probable human lethal dosages at 50-500 or 500-5000 mg/kg, respectively. 

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