Kinetics and mechanism for the reaction of phenethyl p-bromobenzenesulphonate with substituted pyridines under high pressures

Abstract

Kinetic studies of the reaction of phenylethyl p-bromobenzenesulphonate with substituted pyridines at 1–2000 atm. and 35–50 °C in acetonitrile were carried out by the electrical conductivity method. From the activation volume and activation entropies, it can be deduced that the phenethyl system has more S_N2 character in the transition state, comparing with the benzyl function upon raising the pressure, the Hammett ρ and Brönsted β values increase, indicating that the reaction has increasing S_N2 character with increasing pressure.