ISSN:
0030-493X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 70 eV electron impact mass spectra of some 1,3,4-thiadiazolo[3,2-a]pyrimidin-7-one and isomeric-5-one derivatives are discussed with the aid of defocused metastable spectra and exact mass measurements. The compounds are shown to be very stable to electron impact and ring contraction reactions are in most cases the characterstic fragmentations. Most importantly, the 7-one derivatives fragment by a retro-Diels-Alder process which does not occur in the 5-one isomers. This provides a diagnostic tool for differentiation between the isomers and for the unequivocal assignment of the structure.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/oms.1210190906
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