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One-Step Synthesis of Imidazolo-Heteroarenes from Heteroarene N-Oxides
J. M. Keith*
Johnson & Johnson Pharmaceutical Research and Development, San Diego, USA
19 March 2008 (online)
A one-step procedure for the introduction of an imidazole unit into unsubstituted, mono-, and disubstituted heteroarene N-oxides is described. Thus treatment of various pyridine, quinoline, isoquinoline, pyrimidine N-oxides with sulfuryl diimidazole at elevated temperatures leads to the corresponding α-imidazoloheteroarenes in fair to excellent yields. Electron-rich N-oxides led to optimum yields under mild conditions, whereas electron-poor, sterically encumbered substrates required longer reaction times and higher temperatures. A mechanism is proposed.