Azelaeic acid

Carbon—nitrogen double bonds in imines, hydrazones, oximes, nitrones, azines, and substituted diazomethanes can be cleaved, yielding mainly ketones, aldehydes and/or carboxyHc acids. Ozonation of acetylene gives primarily glyoxal. With substituted compounds, carboxyHc acids and dicarbonyl compounds are obtained for instance, stearoHc acid yields mainly azelaic acid, and a smaH amount of 9,10-diketostearic acid. 

Mliphatic dibasic acids such as succinic acid, adipic acid, azelaic acid, and sebacic acids have also been used to make alkyd resins. Their linear chain stmcture lends higher flexibiUty and lower viscosity to the resin as compared to the rigid aromatic rings of phthaUc acids. 

Cleavage of an alkenoic acid can be carried out with permanganate, a permanganate—periodate mixture, periodate or with nitric acid, dichromate, ozone, or, if the unsaturation is first converted to a dihydroxy compound, lead tetraacetate (71,73). Oxidative ozonolysis is a process for the manufacture of azelaic acid [123-99-9] and pelargonic acid (74). 

The mixed oxidation products are fed to a stiU where the pelargonic and other low boiling acids are removed as overhead while the heavy material, esters and dimer acids, are removed as residue. The side-stream contains predominately azelaic acid along with minor amounts of other dibasic acids and palmitic and stearic acids. The side-stream is then washed with hot water that dissolves the azelaic acid, and separation can then be made from the water-insoluble acids, palmitic and stearic acids. Water is removed from the aqueous solution by evaporators or through crystallization (44,45). 

A U.S. patent describes the reaction of commercial oleic acid with hydrogen peroxide in acetic acid foUowed by air oxidation using a heavy metal compound and an inorganic bromine or chlorine compound to catalyze the oxidation. ExceUent yields of dibasic acids are obtained (up to 99%) containing up to 72% azelaic acid (55). 

A novel route to azelaic acid is based on butadiene. Butadiene is dimerized to 1,5-cyclooctadiene, which is carbonylated to the monoester in the presence of an alcohol. Hydrolysis of this ester foUowed by a caustic cleavage step produces azelaic acid in both high yield and purity (56). 

Miscellaneous Derivatives. Fimehc acid is used as an intermediate in some pharmaceuticals and in aroma chemicals ethylene brassylate is a synthetic musk (114). Salts of the diacids have shown utUity as surfactants and as corrosion inhibitors. The alkaline, ammonium, or organoamine salts of glutaric acid (115) or C-5—C-16 diacids (116) are useflil as noncorrosive components for antifreeze formulations, as are methylene azelaic acid and its alkah metal salt (117). Salts derived from C-21 diacids are used primarily as surfactants and find apphcation in detergents, fabric softeners, metal working fluids, and lubricants (118). The salts of the unsaturated C-20 diacid also exhibit anticorrosion properties, and the sodium salts of the branched C-20 diacids have the abUity to complex heavy metals from dilute aqueous solutions (88). 

Azelaic acid [123-99-9] M 188.2, m 105-106". Crystd from H2O (charcoal) or thiophene-free benzene. The material cryst from H2O was dried by azeotropic distn in toluene, the residual toluene soln was cooled and filtered, the ppte being dried in a vacuum oven. Also purified by zone refining or by sublimation onto a cold finger at 10" torr. 

Azelaic acid is made by the ozonolysis of another natural product, oleic acid ... 

CH3(CH2)7C00H + H00C(CH2)7C00H Sebacic acid is used for nylon 610 and azelaic acid for nylon 69. 

In addition several other materials have been reported by industrial companies, but have not at the time of writing been commercialised. These include the product of condensation of 2,2-bis-(p-aminocyclohexyl)propane (VI) (Figure 18.28) with a mixture of adipic and azelaic acid (Phillips Petroleum), a research material produced in the old German Democratic Republic obtained by melt condensation of /ranj -cyclohexane-l,4-dicarboxylic acid (VII) (Figure 18.28) and the two trimethylhexamethylenediamine isomers used in the manufacture of Trogamid T, and another amorphous material (Rilsan N by Ato Chimie). 

Azinphos methyl Azelaic acid Aziridine Azo dyes... 

There has been only one major use for ozone today in the field of chemical synthesis the ozonation of oleic acid to produce azelaic acid. Oleic acid is obtained from either tallow, a by-product of meat-packing plants, or from tall oil, a byproduct of making paper from wood. Oleic acid is dissolved in about half its weight of pelargonic acid and is ozonized continuously in a reactor with approximately 2 percent ozone in oxygen it is oxidized for several hours. The pelargonic and azelaic acids are recovered by vacuum distillation. The acids are then esterified to yield a plasticizer for vinyl compounds or for the production of lubricants. Azelaic acid is also a starting material in the production of a nylon type of polymer. 

The dicarboxylic acid chlorides from sebacic and azelaic acid react with 2 moles of enamine to give the tetraketone (117), which on base cleavage... 

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