Organic lubricating compositions containing esters of benzotriazole

An organic composition comprising oils of lubricating viscosity or greases prepared therefrom containing a minor anti-rust improving amount of an oil-soluble ester of an adduct of benzotriazole and an unsaturated dicarboxylic acid or anhydride thereof selected from the group consisting essentially of maleic anhydride, fumaric acid and acetylene dicarboxylic acid prepared by reacting said benzotriazole and said unsaturated dicarboxylic acid or anhydride thereof in a mole ratio of from about 0.5:1 to about 2:1 benzotriazole to acid or anhydride at a temperature of from about 80 to about 250.degree. C and thereafter esterifying said adduct.