3-Hydroxy-6-[(4-hydroxyphenylamino)methylene]cyclohexa-2,4-dienone and 2-hydroxy-6-[(4-hydroxyphenylamino)methylene]cyclohexa-2,4-dienone.

The title compounds, both C(13)H(11)NO(3), exist as the keto-amine tautomers, and the formal hydroxyl H atoms, which display strong intramolecular hydrogen bonds, are located on the N atoms. This is a verification of the preference for the keto-amine tautomeric form in the solid state. The 2-hydroxy isomer has two independent molecules, with the molecules linked by intramolecular N-H.O and O-H.O and intermolecular O-H.O hydrogen bonds into three-dimensional networks.