The reactions of four 4-nitrobenzofurazans (4a 4d) substituted at the 7 position with (a) N- ethyl,(b) N-butyl,(c) piperidino, or (d) pyrrolidino groups have been examined with sulfite ions and with hydroxide ions in water DMSO (80: 20, v/v). Addition of sulfite at the 5 position gives σ adducts with equilibrium constants ca. 105 lower than that for the formation of the corresponding adduct from 4-nitrobenzofurazan. These reductions are attributed to the ...
