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Synthesis, structure and mass spectral fragmentation of a series of substituted furazano[3,4‐ b ]quinoxaline 1‐oxides and their deoxides
Author(s) -
Gallos John K.,
Lianis Pygmalion S.,
Rodios Nestor A.
Publication year - 1994
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.5570310237
Subject(s) - chemistry , quinoxaline , fragmentation (computing) , mass spectrum , triphenylphosphine oxide , spectral line , electron ionization , triphenylphosphine , computational chemistry , mass spectrometry , medicinal chemistry , organic chemistry , ion , catalysis , physics , chromatography , astronomy , computer science , ionization , operating system
A series of substituted furazano[3,4‐ b ]quinoxaline 1‐oxides have been prepared by oxidation of the respective 2,3‐bis(hydroxyimino)‐1,2,3,4‐tetrahydroquinoxalines with nitric acid and their structure was confirmed by means of their nmr spectra. A very rapid equilibrium occurs between their two isomeric N ‐oxide forms via the dinitroso equivalent, and the influence of the 6(7)‐substituents on the equilibrium is discussed. These compounds were easily deoxygenated by triphenylphosphine in quantitative yields to the corresponding furazans. The electron impact mass spectra of both of the above series of compounds have also been recorded and their fragmentation pattern is discussed.