Vm. Vinogradov et al., SYNTHESIS OF N-HYDROXYPYRAZOLES WITH ELECTRON-ACCEPTING SUBSTITUENTS IN THE RING, Mendeleev communications, (4), 1996, pp. 139-140
A method for the synthesis of N-hydroxynitropyrazoles by oxidation of
pyrazolate anions with KHSO5 in aqueous solution at constant pH has be
en developed.