I. Al-Showaier, A. Hallberg, K. Schram
May 1, 1986
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0
Influential Citations
2
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Journal
Journal of Heterocyclic Chemistry
Abstract
Electron impact induced fragmentation patterns of 5H-dibenz[b,f]azepine (1a), 10,11-dihydro-5H-dibenz-[b,f]azepine (2a) and some 5-substituted derivatives were investigated using metastable ion studies, exact mass measurements and deuterated analogues. Studies employing 4,6-dideuterio derivatives indicate that the formations of ions of m/e 191, 180, 167, 166 and 152 are associated with a variety of skeletal reorganization processes accompanied by hydrogen (or deuterium) transfers involving peri (4- or 6-) hydrogen (or deuterium) atoms. The methyl radical expelled in the formation of the M-15 ion in the spectrum of 2a is derived from the benzylic carbon(s). A similar process is, in part, responsible for the expulsion of a methyl radical from the molecular ion of 5-methyl-10,1 1-dihydro-5H-dibenz[b,f]azepine (2c) based on the fragmentation of the trideuteriomethyl derivative (2d). Side chain α-cleavage processes dominate the spectra of (5H-dibenz[b,f]azepine-5-yl)acetaldehyde diethylacetal and its 10,11-dihydro analogue. Hydrogen atom transfer processes involving benzylic hydrogen atoms occur in the fragmentation of the 10,11-dihydro-5H-dibenz[b,f]azepines 2a, 2c and 2e.