ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The electron-impact-induced fragmentation of 1-phenyl-3-methyl-5-pyrazolone and six 4-acyl substituted derivatives, have been studied with the aid of deuterium labelling, high resolution mass measurements and the metastable defocusing technique. The mass spectra of the pure keto and the pure enol forms do not show any significant differences. The predominant decomposition of the 4-acyl substituted pyrazolones is the α-cleavage with respect to the carbonyl group leading to intense peaks at m/e 201 by loss of the alkyl group. In the case of benzoyl and ethoxycarbonyl derivatives the α-cleavage is associated with a specific hydrogen rearrangement causing the loss of a benzene and an ethyl alcohol molecule, respectively.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210070114
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