4-Hydroxy-7-methoxy-2-methyl-5H-1-benzopyrano[4,3-b]pyridin-5-one

The title compound, C14H11NO4, consists of a methoxy-substituted coumarin s keleton fused to a 2-methyl-4-pyridone ring. The ring system of the molecul e is approximately planar and the methoxy group is roughly coplanar with th e ring plane. The 4-pyridone ring exists in a 4-hydroxy tautomeric form and is stabilized by an intramolecular hydrogen bond between the O-H and C=O g roups. Comparison of the results with those found for other structures cont aining the 4-pyridone substructure reveals a substantial effect of the natu re of the substituents bonded to the pyridine ring on the keto-enol tautome rism.