2-pyridinium fatty acids

Rosen et aL [17] developed a variant of this procedure in which a small amount of ethanol was added to the solution. The method had to be calibrated for each individual type of betaine, by titrating pure material and adjusting the volume of ethanol until a result of 100% was obtained. Using 0.001 M sodium dodecanesulphonate as titrant they successfully titrated the two main types, 2-pyridinium fatty acids of different chain lengths, A -dodecyl-A -benzyl-A -methylglycine and nine commercial betaines. 

Quinolizinium and other fused pyridinium salts are formed when a-methylheterocycles react with 2,4,6-triphenylpyrylium, which thus behaves as a C3-synthon <96MC99>. Pyrylium salts also feature in a stereocontroUed route to conjugated dienynes which has led to a synthesis of Carduusyne A, a marine metabolic fatty acid <96TL1913> and in the formation of pyridinium containing crown ethers <96LA9S9>. 

A nonpolar solubilizate such as hexane penetrates deeply into such a micelle, and is held in the nonpolar interior hydrocarbon environment, while a solubilizate such as an alcohol, which has both polar and nonpolar ends, usually penetrates less, with its polar end at or near the polar surface of the micelle. The vapor pressure of hexane in aqueous solution is diminished by the presence of sodium oleate m a manner analogous to that cited above for systems in nonpolar solvents. A 5% aqueous solution of potassium oleate dissolves more than twice the volume of propylene at a given pressure than does pure water. Dnnethylaminoazobenzene, a water-insoluble dye, is solubilized to the extent of 125 mg per liter by a 0.05 M aqueous solution of potassium myristate. Bile salts solubilize fatty acids, and this fact is considered important physiologically. Cetyl pyridinium chloride, a cationic salt, is also a solubilizing agent, and 100 ml of its A/10 solution solubilizes about 1 g of methyl ethyl-butyl either m aqueous solution. 

Water Repellency. Water repellents may be applied to cotton fabrics to be used for special purposes, such as tentage. The simplest water-repellent treatment is the application of wax either in emulsion form or as solution. The addition of certain salts, such as aluminum acetate, improves the durability of the treatment. A more durable process of treating for water repellency consists of treating the fabric with a quaternary pyridinium compound containing a long-chain fatty acid radical and curing, whereupon presumably a chemical reaction with the cellulose occurs, affixing the radical to the cellulose. 

Johnson and coworkers investigated the cracking and isomerization of various alkanes such as nonane, tetradecane and 2-methylpentane in acidic pyridinium chloride-aluminum chloride ionic liquids. Similar product types to the cracking of hexane (above) were observed and after 15 days some polymerization of the cracked products had occurred [91]. A similar reaction occurs vyith fatty acids (such as stearic acid) or methyl stearate, which undergo isomerization, cracking, dimerization, and oligomerization reactions. This has been used to convert solid stearic acid into the more valuable liquid isostearic acid [92] (Scheme 5.2-41). The isomerization and dimerization of oleic acid and methyl oleate have also been found to occur in chloroaluminate(iii) ionic liquids [93]. 

A reduction in the corrosive action of water is an extremely important property of surfactants. The mechanism of this phenomenon has been presented in a work by Somasundaran and Huang [89], The authors assume that the adsorbed film formed at the interface efficiently separates the water from the metal surface. Experiments confirming the anticorrosive action of surfactants have been presented in several works [90-94]. The following compounds were used in the experiments as additives cationic surfactants (cetyl pyridinium chloride and trimethyl ammonium bromide) [89], ethoxylated fatty acids [90], ethoxylated fatty alcohols [91], and ethoxylated sorbitan esters [92-94]. 

Niphatidae 140-150 160-180 Amphimedon, Cribochalina, Niphates Acetylenic derivatives, macro-heterocycles, cyclopropanic fatty acids, S/ P sterols, isonitriles, isothiocyanates, pyridine derivatives (3-alkyl pyridinium), merosesquiterpenes... 

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