Kinetics of solvolysis of substituted ω-bromo-2-acetonaphthones in aqueous ethanol

Abstract

The kinetics of the solvolysis of ω-bromo-2-acetonaphthone in 70, 80, and 90% ethanol have been measured at several temperatures. The Grunwald–Winstein m value is 0.155 ±0.005 over the temperature range of 55–80°. The Hammett equation applies very well to the solvolysis of 6-substituted ω-bromo-2-acetonaphthones and the ρ value in 80% ethanol is 0.33 at 80°. The first-order rate constants are increased by electron-withdrawing groups and decreased by electron-donating groups. The products indicate that there is no rearrangement involving carbonyl oxygen and naphthyl group in the transition state. The reaction may be a simple nucleophilic displacement of bromide by solvent molecules.