Fluorescence spectroscopic study on tautomeric equilibria of 2(1H)-pyridones

Abstract

The minor tautomers of 2(1H)-pyridones (1a–h), the pyridinol forms, have been directly observed in fluorescence spectra. The ratios of the pyridinol form obtained from the measurements correspond to the tautomeric equilibria and the substituent effects of methyl groups. Thus, the usefulness of fluorescence measurements for the study of the tautomeric properties of 2(1H)-pyridones in solution has been substantiated.