Solvolysis of N-Sulfonoxyacetanilides in Aqueous and Alcohol Solutions: Generation of Electrophilic Species

Article abstract of DOI:10.1021/ja00331a036

A series of ring-substituted N-sulfonoxyacetanilides (1a-f) were synthesized, and their solvolysis reactions in aqueous and alcohol solvents were studied.These compounds serve as models for the carcinogenic metabolites of polynuclear aromatic amides.Kinetic and product studies yielded evidence for solvolysis via N-O bond cleavage in aqueous solution with generation of tight ion pairs and solvent-separated ion pairs.The tight ion pairs, which cannot be trapped by nucleophiles or reducing agents, give rise to o-sulfonoxyacetanilides, while the solvent-separated ion pairs can be trapped by these reagents to yield ring-substituted compounds and reduction products.The para-substituted N-sulfonoxyacetanilides yield substantial amounts of highly electrophilic p-benzoquinone imine derivatives such as 10 during solvolysis in aqueous media.In ethanol these esters solvolyze exclusively via S-O bond cleavage with apparent production of SO3.This study demonstrates that electrophilic species other than nitrenium ions can be generated during the solvolysis of N-sulfonoxy-N-arylamides.These species may play a role in the in vivo activity of these metabolites.