KINETICS OF REACTIONS OF O-(2,4-DINITROPHENYL) BENZALDOXIMES WITH METHYLAMINE, CYCLOHEXYLAMINE AND PIPERIDINE. REACTIVITY AT DIFFERENT ELECTROPHILIC SITES

Article abstract of DOI:10.1016/S0040-4020(01)86155-X

Kinetics of reaction of E-O-(2,4-dinitrophenyl) benzaldoximes have been studied with MeNH2, cyclohexylamine (CHA) and piperdine (PiP) in 1:1 (v/v) ethanol-water at 35+/-0.1 deg C under pseudo first order conditions.The reactions are overall second order, first order with respect to each reactant.Hammett plots are linear with a ρ value of +0.75 for MeNH2, +0.61 for CHA and +1.25 for PiP.MeNH2 and CHA predominantly give the corresponding N-(2,4-dinitrophenyl)amine with attack at the aromatic carbon in sharp contrast to earlier observation with OH^-.With piperidine both elimination and substitution products are obtained, the former product predominanting when strong electron-withdrawing substituents are present in the phenyl ring of the oxime.