Kinetics of the reaction of phenacyl bromide with substituted 2-phenylthiazolidines

Abstract

The kinetics of the reaction of phenacyl bromide with several 2-(<i>m</i>- or <i>p</i>-substituted phenyl)thiazolidines have been studied at 30.0°, 35.0° and 43.0°C in ethanol. The reaction follows second order kinetics, first order in each reactant. Electron-releasing substituents in SPT facilitate the reaction, whereas electron-withdrawing substituents have a retarding effect. The correlation with σ values yields a better ρ value of -1.93 at 43.0°C. A similar correlation at 30.0°C provides a ρ value of -1.14. From the Bronsted plot the value of α= 0.91 is obtained. There is evidence for a triangular transition state in the reaction.