4-Pyridone4-Pyridone is an organic compound with the formula. It is a colorless solid.Preparation4-Pyridone, and its derivatives, are prepared from 4-pyrone and amines in protic solvents.Tautomerism4-Pyridone exists a keto-enol tautomerism with its enol tautomer 4-hydroxypyridine. In solution, the keto tautomer is favoured, and the enol tautomer only becomes important in very dilute solutions or solutions of non-polar solvents. However, the enol tautomer is dominant in the gas phase.Derivativesis an aquatic herbicide that contains a 4-pyridone subunit.