THE QUESTION OF SULFOQUINONE INTERMEDIATES REVISITED

Results from UV-VIS spectroscopy and reactivity studies on the reactio n between the phenolsulfonyl chloride, 4, and aliphatic amines in acet onitrile suggest that simple reduction of steric hindrance around the amine nitrogen is responsible for a switch of the reaction mechanism f rom one where the amine, acting as a base, promotes dehydrochlorinatio n to sulfoquinone 2 to one where fast nucleophilic attack occurs at th e sulfonyl sulfur affording the N-sulfonylammonium derivatives 6 which , in a subsequent stage, yield the final reaction products.