Mass-spectral study of heterocyclic analogs of 4-dimethylamino- and 4-azidochalcones

✍ Scribed by M. F. Budyka; M. M. Kantor; A. P. Pieshkova

• Publisher: Springer US
• Year: 1991
• Tongue: English
• Weight: 337 KB
• Volume: 27
• Category: Article
• ISSN: 0009-3122
• DOI: 10.1007/bf00474000

✦ Synopsis

The predominant pathway in the mass-spectral fragmentation of 4-dimethylamino-and 4-azidochalcones under the influence of electron impact is cleavage of the aryl--CO and CO--.CH bonds and localization of the charge on the fragment with the lower ionization energy. The characteristic "chalcone" rearrangement with the ejection of a molecule of CO from the molecular ion and subsequent cyclization and aromatization of the stilbene derivative is also observed; in the case of azides this process takes place only after the loss of a molecule of nitrogen by the molecular ion. The differences in the pathways of fragmentation of the hetero analogs make it possible to identify compounds with 04 fl, and "1 orientations of the substituent relative to the heteroring nitrogen atom.

In this research we studied the behavior under the influence of electron impact (El) of 4-dimethylaminochalcone (la) and 4-azidochalcone (Ib) as compared with the corresponding heterocyclic analogs IIa, b-VIIa, b, and IX and vinylog VIII.

Ar CO CIi Cll..