INVESTIGATION OF BENZIMIDAZOLONES .7. A C-13-NMR AND N-15-NMR STUDY OF SOME NITRO BENZIMIDAZOLONES

C-13 and N-15 NMR data are reported for series of nitro substituted benzimidazolones in comparison with the results obtained both here and with those published earlier for the unsubstituted benzimidazolone. It is shown that all of the compounds considered exist essentially as the benzimidazolone rather than as its corresponding 2-hydroxy tautomer. Thus, the presence of nitro groups appears to have no influence on this form of tautomerism.