Benzofuroxans

This chapter describes the structure, physical properties, and preparation methods of benzofuroxans. It also presents the available types of substituent groups on the benzene nucleus, such as (1) alkyl and aryl benzofuroxans, (2) halobenzofuroxans, (3) nitrobenzofuroxans, and (4) heterosubstituted benzofuroxans; and the reactions they undergo. Some other furoxano-fused compounds which subject to the limitation that the ring adjacent to the furoxan is aromatic and six-membered are also considered. The benzofuroxans are only weak oxidizing agents which do not show other properties commonly associated with the peroxy linkage. Benzofuroxan spectra are found to have similarities with furoxans and nitroso compounds. The spectroscopic properties of benzofuroxans are investigated by––infrared spectra, ultraviolet spectra, nuclear magnetic resonance spectra, and X–ray diffraction. Benzofuroxan may be obtained by oxidation of o-quinone dioxime. The benzofuroxan derivatives with their melting points are tabulated. The reaction of the heterocyclic ring undergoes electrophillic attack, oxidation, and reduction; whereas, reactions of homocyclic ring undergoes only electrophillic attack and nucleophillic attack. A few commercial applications of benzofuroxans and a wide range of biological activity of benzofuroxan and some of its derivatives are also provided.