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A 15 N NMR investigation of some azolopyridines
Author(s) -
Stefaniak L.,
Roberts John D.,
Witanowski M.,
Hamdi B. T.,
Webb G. A.
Publication year - 1984
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270220403
Subject(s) - indolizine , pyridine , nmr spectra database , nitrogen , chemistry , spectral line , nitrogen atom , chemical shift , molecule , carbon 13 nmr satellite , crystallography , computational chemistry , stereochemistry , ring (chemistry) , physics , organic chemistry , quantum mechanics
Abstract 15 N NMR chemical shift data are presented for 14 azolopyridines, together with the results of INDO/S‐SOS calculations of nitrogen shieldings. Previous 14 N NMR results for some of these compounds are reinterpreted. The 14 N data and their assignments are shown to be reliable for the indolizine nitrogen atom from arguments based on relative line widths. The pyridine‐type nitrogens are more reliably assigned from the 15 N spectra combined with the results of the INDO/S‐SOS calculations for individual molecules. A combination of 14 N and 15 N NMR spectra, together with the shielding calculations, provides a basis for unambiguous assignments of all the various nitrogen environments considered.