The reactions of a series of secondary alicyclic amines with 4-methylphenyl and 4-methoxyphenyl chloroformates are subjected to a kinetic investigation in water, at 25.0ЊC, ionic strength 0.2 M (KCl). Under amine excess, pseudo-first-order rate coefficients (k obs ) are found for all reactions. Plots of k obs vs [NH] (NH is the free amine) are linear, with the slope (k N ) pH independent, except the reactions of 1-(2-hydroxyethyl)piperazine with both substrates at pH 6.2-7.3. The Bro ¨nsted-type plots for the k N values for the aminolysis of both chloroformates are linear, with slopes ca. 0.3, which is consistent with rate-determining formation of a zwitterionic tetrahedral intermediate (T Ϯ ). With the pK a and log k N data for the present reactions, together with those for the same aminolysis of phenyl and 4-nitrophenyl chloroformates, two dual parametric equations are found for log k N as a function of pK a of the nucleophile, Hammett sigma of the "nonleaving" group, and pK a of the "nonleaving" group, with coefficients  N ϭ 0.3, nlg ϭ 0.7, and  nlg ϭ Ϫ0.2, respectively.