Novel synthesis of 3-monosubstituted furoxans

The nitro group in 3-substituted 4-nitrofuroxans (4-nitro-1,2,5-oxadiazol 2-oxides) can be replaced by the hydride ion under the action of NaBH₄ in EtOH, and this reaction is convenient for the preparation of 3-monosubstituted furoxans.