Alkyl arylstearates and process of producing same

摘要

The invention comprises alkyl arylstearates of general formula where x + y = 15, Ar is aryl, R1 is hydrogen or an alkyl, cycloalkyl or alkyl substituted cycloalkyl group of 4-18 carbon atoms, or together with R2 is a divalent alkylene group containing from 4-18 carbon atoms and R2 and R3 are alkyl cycloalkyl or alkyl substituted cycloalkyl groups containing from 4-18 carbon atoms. The compounds may be prepared in two stages. In the first stage a substituted aromatic compound of the formula is condensed with an hydroxystearate of the formula where R4 is methyl or ethyl, in the presence of boron fluoride, the methyl or ethyl arylstearate so formed being hydrolysed to give the free arylstearic acid, which is then esterified with an alcohol of formula R3OH. The first stage of the invention is preferably carried out at elevated temperatures, e.g. 120-180 DEG C. in the presence of a dehydrating agent such as phosphoric acid, zinc chloride or phosphoric anhydride, in a proportion of 1/4 to 2 mols. per mol. of hydroxystearate. The boron fluoride is preferably present in 1/2 to 3 mols. per mol. of hydroxystearate. The methyl or ethyl arylstearate may be isolated by neutralizing the reaction mixture and then distilling it under reduced pressure. The hydrolysis may be carried out by adding the methyl or ethyl amylstearate to a boiling solution of a strong base, e.g. caustic soda or potash, calcium or barium hydroxide, in an aqueous alcohol. The mixture is kept at elevated temperature for a time and then cooled and acidified with e.g. 5 per cent aqueous hydrochloric acid when the liberated arylstearic acid separates out on top of the aqueous phase. The esterification of the acid may be carried out in the presence of an acid catalyst such as sulphuric acid benzene sulphonic acid, or b -naphthylsulphonic acid, and an inert solvent such as benzene. The excess water is azeotropically distilled off and the excess inert solvent evaporated. Specified substituents Ar are phenyl or naphthyl and specified substituents for R1, R2 and R3 are butyl, hexyl, ethylhexyl, cyclohexyl, methylcyclohexyl, dimethyl cyclohexyl, ethylcyclohexyl, diethylcyclohexyl, bicyclodecyl, dodecyl, palmityl and stearyl. Examples are given of the preparation of 2-ethylhexyl dibutylphenylstearate, dodecyl 2-ethylhexylphenylstearate, butyl dodecylphenylstearate, butyl di-2-ethylhexylphenylstearate, 2-ethylhexyl bicyclododecylphenylstearate, butyl stearylphenylstearate, methylcyclohexyl cyclohexylphenylstearate, 2-ethylhexyl dodecylnaphthylstearate, stearyl tetrahydronaphthylstearate and their corresponding methyl compounds.