Substituent effects using ¹³C chemcial shifts for a series of substituted 2-phenyl-3-(pyridin-2-yl)-1,3-thiazolidin-4-ones with a comparison to similarly substituted 1,3-thiazolidin-4-ones

Substituted 2,3-diphenyl-1,3-thiazolidin-4-ones and substituted 3-benzyl-2-phenyl-1,3-thiazolidin-4-ones have been shown to exhibit good correlations using ¹³C chemical shift measurements (substituents chemical shifts or ses) for substituents placed on the phenyl and benzyl moieties versus Hammett a constants; the chemical shifts for C(2), C(4) and C(5) in the thiazolidinone ring have been the focus of interest. In some instances the correlations can be further improved by using dual substituent parameters. In this study the effects of substituents on ¹³C chemical shifts in the thiazolidinone ring at C(2), C(4) and C(5) were measured for a series of substituted 2-phenyl-3-pyridin2-yl-1,3-thiazolidin-4-ones. The chemical shift changes were compared to the two aforementioned series of thiazolidin-4-ones.