Improved Oxidation of Active Methyl Group of N-Heteroaromatic Compounds by Selenium Dioxide in the Presence of tert-Butyl Hydroperoxide

The oxidation of active methyl group of N-heteroaromatic compounds including both of bicyclic and monocyclic compounds using SeO 2 was considerably improved in the presence of tert-butyl hydroperoxde in dioxane to give the corresponding aldehyde or carboxylic acid in the moderate to good yields.The present oxidation proceeds more mildly and more selectively to form aldehyde rather than carboxylic acid, compared with conventional SeO 2 oxidation without tert-butyl hydroperoxide.Selenium dioxide (SeO 2 ) oxidation has been well-documented as mild and selective oxidation and SeO 2 is particularly used for oxidation of active methyl, methylene and methine groups, alcohols and unsaturated bonds and for dehydrogenation of ethylene compounds.