Carboxylic acids, olefinic

No. Carboxylic acid Olefin Additive monomer (%-yield) Additive dimer (%-yield) Ref. 

Some preparations of olefinic and acetylenic compounds from olefinic and acetylenic starting materials can, in principle, be classified in either the monofunctional or difunctional sections for example, RCH=CHBr - RCH=CHCOOH, carboxylic acids from halides (Section 25, monofunctional compounds) or carboxylic acid-olefin (Section 322, difunctional compounds). In such cases both sections should be consulted. 

Dehydrative decarboxylation of fi-hydroxy carboxylic acids. Olefins are formed when 3-hydroxy carboxylic acids are refluxed with excess DMF dimethyl acetal in CHCI3 for 5-10 hr. Yields generally are fair to good (50-90%). 

Nitrations in the vapor phase such as these are always accompanied by competing oxidative and decomposition reactions which may produce such organic materials as aldehydes, ketones, alcohols, carboxylic acids, olefins, nitrolefins, and polymers. Such simple compounds as CO2 and CO, NO, and H2O are also end products of the nitration reaction. The nitrator is operated to minimize production of nitrogen, and little excess nitric acid appears in the effluent stream. 

The chemical inertness of alkanes can be overcome if the transformations are carried out at high temperatures. However, the low selectivity of such processes motivates chemists into searching principally for new routes of alkane conversion which could transform them into very valuable products (hydroperoxides, alcohols, aldehydes, ketones, carboxylic acids, olefins, aromatic compounds etc.) under mild conditions and selectively. This is also connected with the necessity for the development of intensive technologies and for solving... 

One of the useful application.s of NMR has been i/i the delerniitiation of functional groups, such as hy droxyl groups in alcohols and phenols, aldehydes, carboxylic acids, olefins, acetylenic hydiogeiis. amines, and amides. Relaiive errors in the range of I % to are reported. 

Carboxylic Acids may be alkylated and homologated via ketoacid, ketoester and olefinic acid intermediates. See section 320 (Carboxylic Acid -Ketone), section 360 (Ester - Ketone) and section 322 (Carboxylic Acid -Olefin)... 

The less hindered f/ans-olefins may be obtained by reduction with lithium or sodium metal in liquid ammonia or amine solvents (Birch reduction). This reagent, however, attacks most polar functional groups (except for carboxylic acids R.E.A. Dear, 1963 J. Fried, 1968), and their protection is necessary (see section 2.6). 

The boric and sulfuric acids are recycled to a HBF solution by reaction with CaF2. As a strong acid, fluoroboric acid is frequently used as an acid catalyst, eg, in synthesizing mixed polyol esters (29). This process provides an inexpensive route to confectioner s hard-butter compositions which are substitutes for cocoa butter in chocolate candies (see Chocolate and cocoa). Epichlorohydrin is polymerized in the presence of HBF for eventual conversion to polyglycidyl ethers (30) (see Chlorohydrins). A more concentrated solution, 61—71% HBF, catalyzes the addition of CO and water to olefins under pressure to form neo acids (31) (see Carboxylic acids). 

Olefins are carbonylated in concentrated sulfuric acid at moderate temperatures (0—40°C) and low pressures with formic acid, which serves as the source of carbon monoxide (Koch-Haaf reaction) (187). Liquid hydrogen fluoride, preferably in the presence of boron trifluoride, is an equally good catalyst and solvent system (see Carboxylic acids). 

Interest in synthetic naphthenic acid has grown as the supply of natural product has fluctuated. Oxidation of naphthene-based hydrocarbons has been studied extensively (35—37), but no commercially viable processes are known. Extensive purification schemes must be employed to maximize naphthene content in the feedstock and remove hydroxy acids and nonacidic by-products from the oxidation product. Free-radical addition of carboxylic acids to olefins (38,39) and addition of unsaturated fatty acids to cycloparaffins (40) have also been studied but have not been commercialized. 

Highly Branched Acids. These acids, called neoacids, are produced from highly branched olefins, carbon monoxide, and an acid catalyst such as sulfuric acid, hydrogen fluoride, or boron trifluoride. 2,2,2-Trimethylacetic acid (pivaUc acid) is made from isobutylene and neodecanoic acid is produced from propylene trimer (see Carboxylic Acids, trialkylacetic acids). 

Rhodium catalyst is used to convert linear alpha-olefins to heptanoic and pelargonic acids (see Carboxylic acids, manufacture). These acids can also be made from the ozonolysis of oleic acid, as done by the Henkel Corp. Emery Group, or by steam cracking methyl ricinoleate, a by-product of the manufacture of nylon-11, an Atochem process in France (4). Neoacids are derived from isobutylene and nonene (4) (see Carboxylic acids, trialkylacetic acids). 

Neo acids are prepared from selected olefins using carbon monoxide and acid catalyst (4) (see Carboxylic Acids, trialkylacetic acids). 2-EthyIhexanoic acid is manufactured by an aldol condensation of butyraldehyde followed by an oxidation of the resulting aldehyde (5). Isopalmitic acid [4669-02-7] is probably made by an aldol reaction of octanal. 

There have been other approaches to obtaining rubber/metal adhesion besides primers or additives consisting of phenolics or epoxies plus halogenated elastomers. For example, carboxylated polymers (olefins and diolefins copolymerized with acrylic acid monomers) have shown excellent adhesion to metals. Very little carboxyl is necessary, and polymers with carboxyl contents as low as 0.1% show good adhesion when laminated to bare steel. When these materials possess... 

Most rosin utilization takes advantage of the carboxyl and olefinic functionalities of the resin acids. 

Homer-Emmons reagents react with trifluoromethyl ketones to form tnfluo romethylated olefins, however, the double bond can isomerize out of conjugation with the carboxylic acid group with the product olefin that bears a y-proton [37] (equation 30)... 

Simple isothiazole-4-carboxylic acids have been made from the corresponding nitriles, which are available in turn from the halogeno derivatives, or directly by the olefin route.5-Aminoiso-thiazole-4-esters and -nitriles are readily obtained by the thioamide route. The 4-acids behave normally and form acid chlorides, esters, amides, and hydrazides. In contrast to the 5-series... 

Nonclassical Wittig reaction, olefination by phosphoranes interaction with carboxylic acid derivatives, in transformation of heterocycles 99JCS(P1)3049. 

Free radical additions to mono-olefins are quite common and can frequently be employed to advantage on a synthetic scale. Formamide, for example, on exposure to sunlight or UV radiation adds to olefins in an anti-Markovnikov sense giving 1 1 adducts that are readily isolated and crystallized. Moreover, since alkyl formamides may be conveniently converted to carboxylic acids by conventional means, the reaction represents a general method of chain extension. 

In the petrochemical field, hydrogen is used to hydrogenate benzene to cyclohexane and benzoic acid to cyclohexane carboxylic acid. These compounds are precursors for nylon production (Chapter 10). It is also used to selectively hydrogenate acetylene from C4 olefin mixture. 

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