Ammonia reactivity in the acylation with 4-nitrophenyl benzoate in a water-2-propanol system

The kinetics of acylation of ammonia with 4-nitrophenylbenzoates in water-2-propanol mixtures was studied. Increase in the reaction rate with increasing proportion of water in the system is attributed to the formation of ammonia solvato complexes with the components of the solvent. By the RHF/6-31G* method were calculated structural and energetic properties of the solvato complexes. The potential energy surfaces of the acylation reaction of ammonia and its solvato complexes were calculated. It was shown that solvation of the transition state decreases the reaction activation energy compared to the gas-phase process. All the reactions proceed by S _N2 mechanism without formation of intermediates, with only one transition state.