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

Abstract

The title compounds, both C<inf>13</inf>H<inf>11</inf>NO<inf>3</inf>, exist as the ketoamine 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.