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Pulse radiolysis study of the reduction of 1‐phenyl‐1‐cyanonitroethylene. Cyclization leading to 5‐amino‐4‐phenylisoxazole
Author(s) -
Deswarte S.,
Bellec C.,
Pucheault J.,
Ferradini C.,
Gilles L.
Publication year - 1980
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570170510
Subject(s) - chemistry , hydroxylamine , radiolysis , microsecond , isoxazole , polarography , pulse (music) , reduction (mathematics) , spectral line , medicinal chemistry , photochemistry , aqueous solution , organic chemistry , physics , geometry , mathematics , astronomy , detector , electrical engineering , engineering
It is known that the electrochemical reduction of the 1‐phenyl‐1‐cyanonitroethylene leads to the formation of a cyclic compound, the 5‐amino‐4‐phenyl isoxazole, but the mechanism of such a cyclization, which is p H dependent, is not clearly established. Pulse radiolytic methods were used to follow the various stages resulting from the reduction of the 1‐phenyl‐l‐cyanonitroethylene by the radical anion COO − in order to obtain a better understanding of the preceding reduction. The transient spectra are studied between 250 and 400 nm for times ranging from 4 microseconds to several minutes after the pulse; one of these spectra concerns the ene hydroxylamine. As expected, the changes and evolution of the spectra are p H dependent and corresponding mechanisms are proposed to explain the cyclization following the formation of the ene hydroxylamine. A general scheme is given taking into account all the results obtained.