Aromatic amides: IX. Temperature effects on the N.M.R. spectra of substituted acetanilides

Abstract

N.m.r. spectra have been measured for several anilides in dimethyl sulphoxide solution for temperatures in the range 40-140°. The change of the N-H chemical shift with temperature depends on the nature of the ortho substituent on the benzene ring, being least when a strong intramolecular hydrogen bond is possible between the amide N-H and the ortho substituent. For 2'-nitroanilides, the 6'-proton becomes increasingly deshielded as the temperature is raised. © 1974, CSIRO. All rights reserved.