Intramolecular interactions in series of oxazole, oxadiazole, and triazole derivatives

Autor: Yu. N. Surov, I. A. Fedyunyaeva, O. A. Ponomarev, N. S. Pivnenko, N. A. Popova
Rok vydání: 1997
Předmět:
Zdroj: Chemistry of Heterocyclic Compounds. 33:707-711
ISSN: 1573-8353
0009-3122
DOI: 10.1007/bf02291804
Popis: A comparison of the PMR spectra of 5-phenyl-2-methyl derivatives of oxazole, 1,3,4-oxadiazole, and 1, 3, 4-triazole with the spectrum of toluene leads to the conclusion that the electron-acceptor character of the heterocycles drops off in the order oxadiazole >oxazole>triazole. The conduction of electronic effects of the substituents by the oxazole ring is at the level of benzene; the 1, 3, 4-oxadiazole ring accomplishes the transmission somewhat better, and the 1,3,4-triazole ring more weakly, than in the case of benzene. The formation of H-complexes with a 1∶1 composition in a system consisting of the azole, phenol, and carbon tetrachloride was investigated by means of IR spectroscopy. The relative n-donor strength, of the heterocycles decreases in the series triazole >oxazole> oxadiazole. The effectiveness of transmission of electronic influence of the substituents in the phenyl radical on the pyridine nitrogen atom, which is the center of complexation, decreases in the series oxazole >oxadiazole>triazole.
Databáze: OpenAIRE
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