Kinetic Study on Nucleophilic Substitution Reactions of 4-Chloro-2-nitrophenyl X-Substituted-benzoates with Cyclic Secondary Amines: Effect of Substituent X on Reactivity and Reaction Mechanism

= 1.25and r = 0.58, indicating that the nonlinear Hammett plot is not due to a change in the rate-determining step(RDS) but is caused by ground-state stabilization through resonance interactions for substrates possessing anelectron-withdrawing group in the benzoyl moiety. The Bronsted-type plot for the reactions of 4-chloro-2-nitrophenyl benzoate ( 1d) with a series of cyclic secondary amines curves downward with β