Kinetics of aminolysis of some antibacterial vinylic ketones Besicity effect of anilines on aminolysis of trans-1,3-diphenyl prop-2-en-1-one

ABSTRACT

The addition of para-substituted anilines on 1, 3-diphenyl prop-2-en-1-one in methanol is of the first order in the amine and of the second order in the amine for the reaction in benzene. The reaction in both solvents involves both general-acid and general-base catalysis. The rates of addition in benzene satisfy a similar rate equation for general-base catalysis, where aniline itself acts as a catalyzing base. Pyridine showed catalysis much more strongly than some aromatic amines. Good Hammett correlations with negative beta values of 0.739-1.715 and of 0.599-0.894 for the reactions in methanol and benzene, respectively, were obtained which suggested a cationic character of the transition state. An catalysis-addition reaction of aromatic amine on vinylic ketone [I] proceeding via a multistep mechanism