Kinetics of hydrogen exchange in 1,3-dinitrobenzene in sodium methoxide–methan[2H]ol solutions

Abstract

Pseudo-first order rate coefficients for protium–deuterium exchange at the 4- and 6-positions of 1,3-dinitrobenzene in methan[²H]ol solution containing 0·2–0·9M-MeO^– have been measured at 75–100 °C by i.r. analysis of the MeOH formed. Second-order rate constants k[log (k/M^–1 s^–1)= 10·8 – 5140/T] were obtained by evaluation of the kinetic activity of the methoxide ions. Comparison with previously determined kinetic parameters relative to the 2-position shows that positional reactivity is determined by the activation energy. The mechanism is discussed in terms of proton removal and internal return.