From carboxylic acid salts

Acid Anhydrides from Carboxylic Acid Salts and Acid Halides 2.133 Acid Anhydrides by Miscellaneous Methods... 

Fallacious acetate I triphenylphosphine I sodium salt Carboxylic acid anhydrides from carboxylic acid salts and iodides Carbonylation under mild conditions... 

A selection of important anionic surfactants is displayed in table C2.3.1. Carboxylic acid salts or tire soaps are tire best known anionic surfactants. These materials were originally derived from animal fats by saponification. The ionized carboxyl group provides tire anionic charge. Examples witlr hydrocarbon chains of fewer tlran ten carbon atoms are too soluble and tliose witlr chains longer tlran 20 carbon atoms are too insoluble to be useful in aqueous applications. They may be prepared witlr cations otlrer tlran sodium. 

Amides are sometimes prepared directly from carboxylic acids and amines by a two step process The first step is an acid-base reaction m which the acid and the amine combine to form an ammonium carboxylate salt On heating the ammonium carboxy late salt loses water to form an amide... 

The two-component waterborne urethanes are similar in nature to the one-component waterborne urethanes. In fact, many one-component PUD s may benefit from the addition of a crosslinker. The two-component urethanes may have higher levels of carboxylic acid salt stabilizer built into the backbone than is actually needed to stabilize the urethane in water. As a result, if these two-component urethane dispersions were to be used as one-component adhesives by themselves (without crosslinker), they would show very poor moisture resistance. When these two-component urethane dispersions are used in conjunction with the crosslinkers listed in Fig. 8, the crosslinkers will react with the carboxylic pendant groups built into the urethane, as previously shown in the one-component waterborne urethane section. This accomplishes two tasks at the same time (1) when the crosslinker reacts with the carboxylic acid salt, it eliminates much of the hydrophilicity associated with urethane dispersion, and (2) it crosslinks the dispersion, which imparts solvent and moisture resistance to the urethane adhesive (see phase V in Fig. 5). As a result of crosslinking, the physical properties may be modified. For example, the results may be an increase in tensile properties and a decrease in elongation. Depending upon the level of crosslinking, the dispersion may lose the ability to be repositionable. (Many of the one-component PUD s may... 

Vinyl acetates are also fluormated by mixtures contammg both acyl hy-pofluorite and perfluoroalkyl hypofluorite, obtained from fluorinatton of the carboxylic acid salts [16 19] (equations 20 and 21)... 

To place the acidity of phenol in perspective, note that although phenol is more than a million times more acidic than ethanol, it is over a hundred thousand times weaker than acetic acid. Thus, phenols can be separated from alcohols because they are more acidic, and from carboxylic acids because they are less acidic. On shaking an ether solution containing both an alcohol and a phenol with dilute sodium hydroxide, the phenol is converted quantitatively to its sodium salt, which is extracted into the aqueous phase. The alcohol remains in the ether phase. 

Electrochemical reduction of oxazolinium salts 36 gives the anions 37, which add efficiently to alkyl halides or, in the presence of McsSiCl, to methyl acrylate, methyl vinyl ketone, and acrylonitrile. Simple acid hydrolysis then gives the ketone products 38 and 39, and this method is quite general since the starting salts are readily prepared from carboxylic acids, R C02H (87TL4411). 

Unsymmetrical as well as symmetrical anhydrides are often prepared by the treatment of an acyl halide with a carboxylic acid salt. The compound C0CI2 has been used as a catalyst. If a metallic salt is used, Na , K , or Ag are the most common cations, but more often pyridine or another tertiary amine is added to the free acid and the salt thus formed is treated with the acyl halide. Mixed formic anhydrides are prepared from sodium formate and an aryl halide, by use of a solid-phase copolymer of pyridine-l-oxide. Symmetrical anhydrides can be prepared by reaction of the acyl halide with aqueous NaOH or NaHCOa under phase-transfer conditions, or with sodium bicarbonate with ultrasound. 

Anhydrides can be formed from certain carboxylic acid salts for example, by treatment of trimethylammonium carboxylates with phosgene ... 

The following are further examples of amides prepared from carboxylic acids/CDI and primary amines activated by magnesium salts (additional examples are reported in ref. [90]) ... 

By use of TV-(trifluoroacetyl)- or TV-(trichloroacetyl)-imidazoleare obtained symmetric aliphatic and aromatic anhydrides even from carboxylic acids that do not form insoluble salts in benzene, ether, or THF (Table 13—1). In this case the acid is treated with the imidazolide in a 2 1 molar ratio, and an insoluble imidazolium trifluoro- or tri-chloroacetate is formed. 

The procedure described here allows for a convenient and efficient preparation in very high yields of large quantities of bromides from carboxylic acids containing an olefinic functionality. The Hunsdiecker reaction is traditionally accomplished by treating anhydrous silver carboxylates with bromine or iodine.2 Heavy metal salts such as mercury,3 lead,4 and thallium5 have also been used successfully as well as tert-butyl hypoiodite.6 The major disadvantages associated with the above methods, such as use of heavy metal salts and non-tolerance towards olefins, has led to the development of a more versatile method using O-acyl thiohydroxamates.7 8 The O-... 

The reactivity of oxiranes with lithium enoiates and related compounds has been widely explored and reviewed . Dianions derived from carboxylic acids react readily with oxiranes, but the reaction can be slowed by steric hindrance . The reaction of oxiranes with dianions of acetoacetates is greatly accelerated by the addition of BF3 Et20 " . Oxiranes react readily with lithium salts derived from nitriles , malonates and analogues , lithiated oxazolines and lithio enamines . 

Similar to inorganic acids, the reaction of carboxylic acids and bases produces carboxylic acid salts. Several of these salts are commonly used in foods and beverages as preservatives. The most common are salts from benzoic, propionic, and sorbic acids. The salts of these acids have names ending with ate, and can often be found in the list of ingredients of baked goods and fruit drinks. Several common preservatives are shown in Figure 15.11. 

Preparation of acid anhydrides Acid anhydrides are prepared from carboxylic acids by the loss of water. For example, acetic anhydride is prepared industrially by heating acetic acid to 800 °C. Other anhydrides are difficult to prepare directly from the corresponding carboxylic acids. Usually they are prepared from acid chloride and sodium carboxylate salt (see below). 

---