Substituent electrophilicities in the NMR spectra of barbituric derivatives.

ABSTRACT

Comparison of the (1) H and (13) C NMR spectra of a series of substituted 5-benzylidene-N,N'-dimethylbarbituric acids (1) revealed chemical-shift variations of different centers that correlated with the theoretical electrophilicities or with the substituent electrophilic constant σ(ω) , in an example of the usefulness of these DFT-based indices.