The Orton Rearrangement in Aprotic Solvents: Iii. The Acid-Catalyzed Chlorination of Anisole by a Series of 4-Substituted N-Chloroacylanilides

Anisole has been chlorinated with a sequence of chlorinating agents generated by the reaction of a series of 4-substituted N-chloroacylanilides (4-X-C6H4NClAc (X = Me, H, and CN)) with a series of carboxylic acids (R—COOH (R = CF3, CCl3, CH2Cl, and CH3)). The isomer ratios of the 2- and 4-chloroanisoles produced in these reactions have been measured for each N-chloroacylanilide – carboxylic acid pair, and are found to be dependent on the strength of the catalyzing acid but independent of the structure of the N-chloroacylanilide within the precision of the reported data. These observations are consistent with both the termolecular scheme proposed in part II of this series and the Soper mechanism. However, evidence derived from these and other observations suggests that the termolecular scheme is still the most probable mechanism for the chlorine transfer reaction.