NUCLEOPHILIC ATTACK ON THE NITRONE TAUTOMERIC FORM OF 1-HYDROXY-2-PHENYLINDOLE

Abstract 1-Hydroxy-2-phenylindole exists in solution in both hydroxylamine and nitrone tautomeric forms: the latter is able to add organometallic compounds, forming stable indolinic aminoxyls, which were also prepared for comparison by an independent way. The title compound, after irradiation with a mercury lamp lead to a spin adduct, whose identification was proved by deuteration of 1-hydroxy-2-phenylindole at different levels. A mechanism similar to that invoked in the photoreaction of phenyl- tert -butylnitrone with nucleophiles has been proposed in order to interpret this behaviour. A macroscale irradiation of 1-hydroxy-2-phenylindole affording several compounds has also been carried out.