Oxidative cyclizations. III. Kinetic studies of the oxidation of 2,4-dinitroaniline and 2-benzoylaniline with (diacetoxyiodo)benzene

Abstract

For the oxidative cyclization of 2,4-dinitroaniline and 2- benzoylaniline with (diacetoxyiodo)benzene in toluene solution, the kinetic orders are unity in amine and oxidant, zero in iodobenzene and cyclic product, and -1 in monomeric acetic acid. These characteristic orders are also those observed for 2-nitroaniline and, together with evidence for a specific solvation effect by acetic acid on the reaction rates of all three amines, indicate that a common mechanism of oxidative cyclization applies to a range of ortho-substituted anilines. For 2-benzoylaniline, there is infrared evidence of an N-H bond in an iodoso intermediate.     Equilibrium constants for the monomer ↔ dimer equilibrium of acetic acid in toluene solution have been determined at four temperatures between 25° and 46°.