Hydroacridines: Part 23.1H and13C NMR spectra ofsym-octahydroacridine, its 9-(3-pyridyl) and 9-(4-pyridyl) derivatives and the correspondingN(10)-oxides. An experimental approach to the diamagnetic anisotropy of the pyridine nucleus

Autor: Maria Marinescu, Calin Deleanu, Francisc Potmischil, Mircea D. Gheorghiu
Rok vydání: 2002
Předmět:
Zdroj: Magnetic Resonance in Chemistry. 40:237-240
ISSN: 1097-458X
0749-1581
DOI: 10.1002/mrc.996
Popis: The complete 1H NMR chemical shift assignments of 1,2,3,4,5,6,7,8-octahydroacridine (1), 1,2,3,4,5,6,7,8-octahydro-9-(3-pyridyl)acridine (2), 1,2,3,4,5,6,7,8-octahydro-9-(4-pyridyl)acridine (3) and the corresponding N(10)-oxides 1a, 2a and 3a, respectively, were achieved on the basis of 400 MHz 1H NMR spectra and proton–proton decoupling, HMQC and NOEDIFF experiments. The spectral data for the above compounds provided the first experimental evidence of the difference in the anisotropy effect of the two non-symmetrical moieties of the pyridine nucleus, and allowed us to ascertain that the shielding effect of the moiety defined by the C(2′)—N—C(6′) atoms is weaker than that of the C(3′)—C(4′)—C(5′) moiety. The 13C NMR spectra of 1–3 and 1a–3a and the effect of N(10)-oxidation on the 13C NMR chemical shifts are also discussed. The N-oxidation of 2 and 3 with m-chloroperbenzoic acid occurred regiospecifically, affording the N(10)-oxides 2a and 3a free of N(1′)-oxide isomers. Copyright © 2002 John Wiley & Sons, Ltd.
Databáze: OpenAIRE
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