Kinetic Study on the Effect of Substituents on the Base-catalysed Darzens’ like Condensations.

The kinetics of the base-catalysed condensation of phenacyl chloride, p-methoxy-, p-methyl and p-chlorophenacyl chlorides with phenanthrenequinone were followed potentiometrically at different temperatures. The condensations follow overall third order kinetics, first with respect to each constituent. The rate of condensation increases vith increasing electron-'withdrawing po- wer of the substituents. The rate also increases as the dielectric constant of the solvent increases. The attempts to achieve acid-catalysed Darzens’ condensations failed with phenanthrenequinone and with p-nitrobenzaldehyde.