Aromatic substitutions with carbanion nucleophiles. III. The kinetics of the reaction of picryl chloride with diethylmalonate anion

Abstract

The reaction between 1-chloro-2,4,6-trinitrobenzene (picryl chloride) and diethylmalonate anion in benzene–DMSO 7:1 v/v solvent has been investigated by means of stopped-flow and uv–visible spectrophotometers. The results support a simple bimolecular aromatic substitution with a fast formation of a Meisenheimer-like coloured intermediate, followed by a slower decomposition to the picryl ester. The latter is rapidly deprotonated by the excess base. The steps of the reaction were followed separately and the rate constants and activation parameters have been measured.