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Mass spectra of 2 H ‐1,4‐benzoxazine and‐benzothiazine hydroxamic acids
Author(s) -
Coutts R. T.,
Hindmarsh K. W.
Publication year - 1970
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.1210030113
Subject(s) - ketene , chemistry , mass spectrum , radical , hydroxamic acid , molecule , benzothiazine , deuterium , oxygen atom , ion , oxygen , medicinal chemistry , photochemistry , stereochemistry , organic chemistry , physics , quantum mechanics
The mass spectra of various benzoxazine and benzothiazine hydroxamic acids and related lactams have been recorded and interpreted. Proposed fragmentations have been substantiated by means of deuterium‐labeling and accurate mass measurements. Abundant molecular ions were observed in all spectra. The benzoxazine hydroxamic acids fragmented initially by expelling an oxygen atom and a COOH radical from the molecular ion. The corresponding benzothiazine hydroxamic acids lost an oxygen atom and an OH radical, whereas their 1,1‐dioxides decomposed by losing an oxygen atom and a ketene or substituted ketene molecule. The expulsion of CO, HCN, CS and SO 2 molecules, as well as alkyl and NO radicals were common subsequent fragmentations.