Etude par RMN du Proton et du Carbone-13 de Pyrimidines Substituées. I—Effets de Substituant dans les Dérivés Méthylés et Aminés

Substituent effects of methyl and amino groups on the chemical shifts of pyrimidine have been investigated by ¹H and ¹³C n.m.r. and compared with similar data obtained for benzene and pyridine. Taking into account pairwise interactions, the chemical shifts calculated by using an additivity relationship are in very good agreement with the experimental results, except for some hindered pyrimidines. This study enabled us to assign the ¹³C n.m.r. spectra of some trisubstituted pyrimidines.