NMR-Spectroscopic Investigation of E/Z-Isomerism in Substituted Dithiocarbacinic Acid Derivatives

Article abstract of DOI:10.1007/BF00808956

NMR-spectroscopic investigations of substituted dithiocarbacinic acid derivatives show the existence of configurational isomers relative to the C=N double bond, but no tautomerism.We applied chemical shift differences in the 1H-, 13C- and 15N-NMR-spectra, N-H and C-H coupling constants and NOE difference measurements in the solvents CDCl3, DMSO-d6 and partly CD3OD in order to discriminate between the isomers and to determine the configurational composition.Compounds 4 and 5 exist as E-isomers in all solvents, compounds 1, 2 and 3 as a mixture of E/Z-isomers.In DMSO-d6 the E-form is the preferred isomer.