4-Pyridone, and its derivatives, are prepared from 4-pyrone and amines in protic solvents.

[1][2][3] 4-Pyridone exists a keto-enol tautomerism with its enol tautomer 4-hydroxypyridine.

In solution, the keto tautomer is favoured,[4] 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.

[5] Fluridone is an aquatic herbicide that contains a 4-pyridone subunit.