J. Riand, M. Chenon, N. Lumbroso-Bader
Jan 15, 1980
Citations
0
Influential Citations
11
Citations
Journal
Journal of The Chemical Society-perkin Transactions 1
Abstract
The free energy of activation for internal rotation about the C–N exocyclic bond of some substituted 4-(NN-di-methylamino)pyrimidines has been determined using 1H and 13C n.m.r. line-shape analysis. Substituent effects on the rotational barrier of the dimethylamino group are evaluated. The influence of the position of the dimethyl-amino group with respect to the nitrogen atoms is discussed, the rotational barrier being higher in the 4- than in the 2-position. An interesting linear correlation between free energies of activation and 1J(C,H) coupling constants for the 4-dimethylamino group has been found.