Kinetics of solvolysis of substituted ω-bromo-1-acetonaphthones in aqueous ethanol

Abstract

The kinetics of solvolysis of ω-bromo-1-acetonaphthone in 70, 80, and 90% ethanol have been measured at several temperatures. The Grunwald–Winstein m value is 0.112 ± 0.005 over the temperature range 55–80 °C. The Hammett equation applies well to the solvolysis of 4-substituted ω-bromo-1-acetonaphthones and the ρ value in 80% ethanol is 0.41 at 80°. The first-order rate constants are increased by electron-withdrawing groups and decreased by electron-donating groups. The nature of the products indicates that there is no rearrangement involving the carbonyl oxygen and the naphthyl group in the transition state. The reaction may be a simple nucleophilic displacement of bromide by solvent molecules.