The preparation of 5-hydroxy-4-nitroso-and 7-hydroxy-4-nitrosobenzofurazan as well as of their 6-chloro and methyl derivatives is described and the oxime structure of these compounds is established. NMR spectra of benzofurazan-4, 5-dione-4-monoxime and benzofurazan-4, 7-dione-4-monoxime show evidence for an interconversion, in solution, of two monoximes, the 4, 5-and 4, 7-derivative prevailing in organic solvents and aqueous ...
