Dinitrogen trioxide-mediated domino process for the regioselective construction of 4-nitrofuroxans from acrylic acids

Article abstract of DOI:10.1002/hc.21166

4-Nitrofuroxans (4-nitro-1,2,5-oxadiazole 2-oxides) were prepared by a dinitrogen trioxide-mediated domino reaction of acrylic acids under the action of NaNO₂ excess in AcOH at room temperature. The reaction proceeds completely regioselectively and presents a new, simple, general, and safe method for the preparation of both 3-aryl- and 3-alkyl-4-nitrofuroxans available with difficulty before. A mechanism for the furoxan ring construction through a four-step one-pot protocol is proposed. The synthesized nitrofuroxans have been characterized by multinuclear NMR spectroscopy and X-ray powder diffraction.