N-Oxidation of 1,4-dihydro-2,6-dimethyl-1- phenyliminopyridine (7) with several peracids was attempted. The main compound obtained was l-phenyl-
2,6-dimethyl-4-pyridone (8), instead of the expected N-oxide (2). The reaction
of phenylhydroxylamine with dimthylrnethoxypyroxonium perchlorate, however,
successfully gave the N-oxide (3), which belongs to a class of nitrones in
which the diazomethine N-oxide group is conjugated with an electron releasing