The ranges of variation of the rate constant (0.031-0.153 L•mol -1 •s -1 ), energy of activation (21-55 kJ/mol), and entropy of activation (88-191 J•mol -1 •K -1 ) for the reaction of benzamide with 3-nitro benzenesulfonyl chloride in aqueous 1,4-dioxane with a concentration of water of 15-40 wt % have been determined by studying the reaction kinetics in the temperature range 298-313 K. The potential energy surface for the gasphase reaction of benzamide with 3-nitrobenzenesulfonyl chloride has been simulated at the DFT B3LYP/ 6-311G(d,p) level of theory; the results of quantum chemical simulation suggest bimolecular nucleophilic substitution mechanism of this reaction.