Carbon-13 NMR spectra of isocoumarin,N-methyl-1(2H)-isoquinolinone and related compounds

The ¹³C NMR spectra of isocoumarin, N-methyl-1(2H)-isoquinolinone and 14 of their 3- and/or 4-substituted derivatives were measured and assigned with the aid of various spectral techniques. The values of the one-bond and some of the long-range ¹³C-¹³C-¹H coupling constants are reported. The effect of substitution on the ¹³C chemical shifts is discussed.