ON THE PREPARATION OF AMINE N-OXIDES BY USING DIOXIRANES

The reaction of heterocyclic aromatic amines, anilines and tertiary am ines with dimethyldioxirane (DMD) was examined. Treatment of heterocyc lic aromatic amines and anilines with a slight excess of DMD at 0 degr ees C afforded the corresponding N-oxides in quantitative conversion y ields. in addition, the oxidation was chemoselective in the presence o f carbon-carbon double bonds. On the other hand, most of the tertiary amines assayed did afford also quantitative yields of the correspondin g N-oxides, although reaction conditions, in particular regarding the amount of DMD required, depended on each substrate. Additional studies carried out on selected substrates suggested that certain N-oxides de rived from tertiary amines deactivate DMD. (C) 1997 Elsevier Science L td.