1H N.M.R. spectra of some 5-substituted-3-isopropyl-6-methyl uracils

Abstract

The 1H n.m.r. spectra of some 5-substituted-3-isopropyl-6-methyl uracils were determined in deuterated dimethyl sulfoxide (d6-DMSO). The substituents are: H, Cl, Br, I, NO2, NH2, N(CH3)2, C6H5, C6H4-NO2-p and C6H4-NH2-p. It has been shown that relative chemical shift (Δδ) of N(1)-H proton of some of the examined compounds correlated linearly with Hammett σm constant for the substituents in position 5 of uracil ring. The correlation with the σm constant was interpreted as providing evidence that the inductive effect of the substituent on chemical shift is dominating one.