Kinetics of the reactions of 2-bromo-3,5-dinitrothiophen with ortho-substituted anilines in methanol. An application of the Fujita–Nishioka equation

Abstract

The rates of anilino-debromination of 2-bromo-3,5-dinitrothiophen (I) by some ortho-substituted anilines (II; X = OMe, Me, Et, Cl, Br, and F) have been measured in methanol. The kinetic results have been treated according to the multiparameter analysis of ortho-effects proposed by Fujita and Nishioka. This treatment of data has also been applied to acid–base equilibria of anilinium ions. The susceptibility constants obtained in the two series of reactions (respectively ρ–2.96 and –2.90, δ 1.31 and 0.56, f–1.83 and –1.70) have been explained by taking into account the structure of the transition states involved.