Electronic and steric effects in the SNAr substitution reactions of substituted anilines with 2,4‐dinitrophenyl 2,4,6‐trinitrophenyl ether in acetonitrile

Rate measurements are reported for the reactions of 12 ring‐substituted anilines with 2,4‐dinitrophenyl 2,4,6‐trinitrophenyl ether (1) in acetonitrile. Formation of the products, the correspondingly substituted 2,4,6‐trinitrodiphenylamines, occurs without the observation of intermediates in detectable amounts by both base‐catalysed and uncatalysed pathways and Hammett ρ value were determined for these processes. The results show that although substituents at the 3‐ or 4‐positions of the anilines have only small steric effects, alkyl substituents at the 2‐position may result in considerable reductions in reactivity. These effects are more pronounced for the base‐catalysed pathway and in 2,6‐dimethylaniline the uncatalysed pathway takes all the reaction flux. In the case of the 2‐fluoro substituent the electronic effect, strong inductive electron withdrawal, is dominant over steric effects.