Proton magnetic resonance spectra of some 1,2-Dithiole-3-ones and 1,2-Dithiole-3-thiones

Abstract

    P.m.r. spectra of 31 derivatives in the title series are tabulated. The chemical shifts of the heterocyclic ring protons, the influence of substituents upon them, the differences between the two systems, and allylic coupling in methyl derivatives are discussed. It was not found possible to make any firm conclusion regarding aromaticity of these systems, but there is some evidence that the bond order of C4 - C5 bond is less than 2.     The p.m.r. spectra of a number of simple aniline derivatives were examined as model compounds. Acetylation of the amino groups causes a downfield shift (0.7-2.2 p.p.m.) in the ortho ring protons.