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Conversion of acetamido‐ and nitro‐substituted ortho ‐azidonitro derivatives of 2,3,4,5‐tetrahydrobenzo [ b ][1,4]dioxocin to the corresponding furoxans and furazans in the gas phase
Author(s) -
Takakis Ioannis M.,
Hadjimihalakis Phaedon M.,
Gross Michael L.,
Hayes Roger N.,
Haas George W.
Publication year - 1993
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210280207
Subject(s) - chemistry , nitro , electron ionization , fragmentation (computing) , ionization , ion , medicinal chemistry , nitrogen , oxygen , chemical ionization , organic chemistry , alkyl , computer science , operating system
Electron impact ionization of the five isomeric 2,3,4,5‐tetrahydro‐9‐azido‐7,8‐dinitro‐, 2,3,4,5‐tetrahydro‐8‐azido‐7,9‐dinitro‐, 2,3,4,5‐tetrahydro‐8‐azido‐7,10‐dinitro‐, 2,3,4,5‐tetrahydro‐7‐azido‐8,9‐dinitro‐, 2,3,4,5‐tetrahydro‐7‐azido‐8,10‐dinitro‐ and the related 2,3,4,5‐tetrahydro‐7‐acetamido‐8‐azido‐9‐nitro‐, 2,3,4,5‐tetrahydro‐7‐acetamido‐9‐azido‐8‐nitro‐, 2,3,4,5‐tetrahydro‐9‐acetamido‐7‐azido‐8‐nitro‐, 2,3,4,5‐tetrahydro‐10‐acetamido‐7‐azido‐8‐nitrobenzo[ b ] [1,4]dioxocin derivatives furnished, after elimination of nitrogen, the corresponding nitro and acetamido dioxocino‐annelated benzofuroxans. Further loss of oxygen from the latter afforded the corresponding benzofurazans. It was shown in two cases that these processes occur primarily upon electron impact ionization, without excluding some small fraction undergoing a thermal degradation process. The proposed fragmentation patterns are supported by high‐resolution and mass‐analyzed ion kinetic energy spectroscopic data. Similar work on the unsubstituted 6,7‐dihydro[1,4]dioxino[2,3‐ f ]‐ and 7,8‐dihydro‐6 H ‐[1,4]dioxepino[2,3‐ f ]‐2,1,3‐benzoxa‐diazole 1‐oxide reveal that loss of oxygen from the molecular ion to furnish the corresponding benzofurazans is the result of electron impact ionization (at least in part).