Kinetics of desulphonative double Smiles' rearrangement of N-(2-hydroxyalkyl)-p-nitrobenzenesulphonamides

Abstract

Support for a mechanism of formation of N-(2-hydroxyethyl)-p-nitroanilines by base-catalysed desulphonation of N-(2-hydroxyethyl)-p-nitrobenzenesulphonamides has been obtained by kinetic investigation. Derivatives bearing alkyl and aryl substituents on nitrogen, or C-alkyl substituents α- or β- to the hydroxy-group have also been studied. Substituent effects on the rate and base dependence of (i) intramolecular aromatic displacement of the sulphonamide group by the neighbouring hydroxy-group and (ii) rearrangement of the intermediate 2-(p-nitrophenoxy)alkylamine have been determined for this double Smiles' rearrangement sequence. Intermediate aminoethers have been detected spectroscopically for the first time and have in some cases been isolated.