Studies of Organic Peroxides. XI. The Reaction of Benzoyl Peroxide with Secondary Amines in Binary Mixed Solvents

Abstract

Abstract The rate constants of the reaction of benzoyl peroxide with some typical secondary amines, namely, diphenylamine, N-methylaniline, and piperidine, were measured in benzene-nitrobenzene binary mixed solvents. The reaction rates of diphenylamine and N-methylaniline are little influenced by the compositions of the solvents, while the reaction of piperidine proceeds more rapidly in nitrobenzene than in benzene. The isokinetic relationship holds for the reaction of piperidine in the binary mixed solvents. The isokinetic temperature is calculated to be 265°K. The analysis of the behavior of these reactions in the mixed solvents leads to the conclusion that, in the cases of diphenylamine and N-methylaniline, there are no specific interactions between the activated complexes and solvent molecules, whereas in the case of piperidine the activated complex is weakly solvated with the polar nitrobenzene. The reaction of benzoyl peroxide with N-methylaniline and N-n-butylaniline was also studied in benzene. These amines have a higher reactivity than would be expected from their basicity. This higher reactivity is probably due to the resonance stabilization of the activated complex besides the formation of a lessionic activated complex.