The kinetics and mechanisms of aromatic halogen substitution. Part XXXIII. Kinetics and products of chlorination of some aryl acetates

Abstract

The rates and products of reaction of 4-methylphenyl acetate, 3,4- and 2,6-dimethylphenyl acetate, and 2,3,5,6-tetramethylphenyl acetate with molecular chlorine in acetic acid have been studied. ‘Abnormal’ reaction paths play a large part in the determination of the products of the chlorination of the first two of these compounds, probably through electrophilic attack on an activated ‘ipso’-position. The observed rates of reaction are compared with those calculated on the basis of additivity of substituent effects; they allow an estimate to be made of the effect of steric inhibition of resonance on the directing power of the acetoxy-group. The product of chlorination of the corresponding phenols are recorded also.