10, 11-ジアリールウンデカン酸メチルおよび11-アリール-9-ウンデセン酸メチルの合成とそれらの抗酸化性およびサビ止め効果

抄録

Methyl 10-undecenoate and mercuric acetate were reacted in methanol to give methyl methoxyacetoxy mercury-undecanoate. The mercurial adduct was then reacted with phenol, o-cresol, m-cresol, p-cresol and o-tert-butylphenol in 1: 5 mole ratio each at 60 °C for one hour in the presence of perchloric acid as a catalyst, giving methyl 10, 11-diaryl undecanoates corresponding to the respective phenols. The reaction of the mercurial adduct and 2, 6-di-tert-butylphenol gave methyl 11- (hydroxy, di-tert-butylphenyl) 9-undecenoate instead of methyl 10, 11-diaryl undecanoate. The mercurial adduct was then reacted with methyl benzoate, dimethyl phthalate, and methyl acetylsalicylate at the same reaction condition for 2 hours, giving methyl 11-methoxycarbonylphenyl-9-undecenoate, methyl 11-dimethoxycarbonylphenyl-9-undecenoate, and methyl 11-acetoxymethoxycarbonylphenyl-9-undecenoate.
All diaryl undecanoates listed above showed antioxidant activity for methyl oleate at 40 °C and 100 °C. However, their activities are somewhat less than the activity of BRA. They were found effective as corrosion inhibitors by the water-dip method with a sample of turbine oil and test pieces o mild steel, aluminium, zinc and brass at the concentrations of 0.2, 0.4, 0.6 and 0.8%. Especially, the derivatives from p-cresol and o-cresol were excellent as corrosion inhibitors. Methyl 11-methoxycarbonylphenyl-9-undecenoate, methyl 11-dimethoxycarbonylphenyl-9-undecenoate and methyl 11- (acetoxy, methoxycarbonylphenyl) -9-undecenoate were converted to its sodium, calcium, strontium and barium soaps, and their activity as corrosion inhibitors was tested with a sample of turbine oil and test pieces of mild steel at the concentrations of 0.2, 0.4, 0.6 and 0.8% by the water-dip method. Regerding the acid components, the activity was ranked in the order of 11- (hydroxy, carboxyphenyl) -9-undecenoic acid>11-dicarboxyphenyl-9-undecenoic acid>11-carboxyphenyl-9-undecenoic acid. As for the base components, strontium and barium soaps were very effective followed by calcium soaps, sodium soaps being slightly less effective.