Abstract The kinetics of the SN Ar reactions of aniline and N-methylaniline with a variety of substituted nitrochlorobenzenes in acetonitrile demonstrate that the formation of the intermediate σ-complex is rate determining. The ratio of the rate constants of the aniline and the N-methylaniline reactions (k A/k M) increases with increasing size of the 6-substituent; with picryl chloride k A/k M reaches a value of over 20 000. The reaction of aniline with 4-X ...
