Nucleophilic substitution in azasydnone-modified dinitroanisoles

Reactions of 3-(4-methoxy-3,5-dinitrophenyl)-1,2,3,4-oxatriazolium-5-olate with <em>N</em>-nucleophiles under mild conditions results in the displacement of the methoxy group leaving 1,2,3,4-oxatriazolium-5-olate (azasydnone) moiety intact. In the case of alkylhydrazines, further cyclization involving nitro group into benzo[<em>d</em>][1,2,3]triazole 3-oxides occurs.