par Declerck, Freddy ;Degroote, Roland ;De Lannoy, J.;Hinkens, Raymonde ;Nasielski, Jacques
Référence Bulletin des Sociétés chimiques belges, 74, 3-4, page (119-128)
Publication Publié, 1965
Référence Bulletin des Sociétés chimiques belges, 74, 3-4, page (119-128)
Publication Publié, 1965
Article révisé par les pairs
Résumé : | Substituted pyridazines, pyrimidines and s‐triazines yield very simple N.M.R. spectra. Substituent effects of electron releasing groups are enhanced in these heterocycles, and surprisingly large shifts occur at the meta positions. The J4–5 in 3,6‐disubstituted pyridazines vary with the electron releasing ability of the substituent located at position 6 and are shown to parallel the bond index P4–5. Nitrogen quadrupole relaxation broadens the signal of 2‐Hydrogen in pyrimidine, whereas the s‐triazine protons yield sharp lines. Copyright © 1965 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim |