Facelli, Julio C.; Orendt, Anita M.; Contreras, Ruben H.; Tufro, Maria F.; De Kowalewski, Dora G. published the artcile< Ab initio and oxygen-17 NMR studies of the substituent effects on the tautomeric equilibrium in 6-X-(1H)-2-pyridones>, SDS of cas: 73018-09-4, the main research area is keto enol tautomerism pyridone substituent effect; oxygen NMR pyridone tautomerism.
17O chem. shifts are found to be highly sensitive probes in the study of keto-enol tautomeric equilibrium due to the strong sensitivity of these shifts to the coordination of the oxygen atom. The large shielding effect observed, both exptl. and theor., for the carbonyl oxygen atom in 2-pyridone suggests that the carbonyl π-electronic system experiences strong conjugation with the formal C3:C4 double bond and/or the nitrogen lone pair. A Cl or NH2 substitution at position 6 of the pyridine ring shifts the tautomeric equilibrium toward the 2-hydroxypyridine form, while a CH3 substitution results in the keto form being predominant, as is the case in the parent compound
Journal of Physical Chemistry published new progress about Conjugation (bond). 73018-09-4 belongs to class pyridine-derivatives, and the molecular formula is C5H4ClNO, SDS of cas: 73018-09-4.