13C N.M.R. spectra of some 5-substituted-3-isopropyl-6-methyl uracils

Abstract

13C 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, J, NO2, NH2, N(CH3)2, C6H5, C6H4-NO2-p and C6H4-NH2-p. It has been shown that 13C chemical shifts of C-5 of some of the examined compounds correlated linearly with the 13C chemical shifts of C-5 in the 5-substituted uracils as well as with the 13C chemical shifts of the substituted carbon in an analogues series of monosubstituted benzenes. The 13C chemical shifts of C-6 in some of the above compounds depend on the steric effects of the substituent in position 5 of the uracil ring. © 1990.