2-Hydr­oxy-6-[(2-methoxy­phen­yl)amino­methylene]cyclo­hexa-2,4-dienone

The mol­ecule of the title compound, C₁₄H₁₃NO₃, adopts the keto–amine tautomeric form. An intra­molecular N—H...O hydrogen bond dictates the essentially planar mol­ecular geometry; the two benzene rings make a dihedral angle of 7.93 (7)°. The crystal packing is stabilized by inter­molecular O—H...O and C—H...O hydrogen bonds.

(Z)-4-[(E)-(4-Butyl­phen­yl)diazen­yl]-6-{[1,3-dihydr­oxy-2-(hydroxy­meth­yl)propan-2-ylamino]methyl­ene}-2-methoxy­cyclo­hexa-2,4-dienone

The title compound, C₂₂H₂₉N₃O₅, is approximately planar with the aromatic rings in a trans configuration with respect to the azo double bond. The eneamine portion of the mol­ecule exists as the keto–amine tautomer, stabilized by a strong intra­molecular N—H...O hydrogen bond. Intra­molecular N—H...O and O—H...O and inter­molecular O—H...O and C—H...O inter­actions influence the conformation of the mol­ecules and the crystal packing.

(E)-5-[(3-Bromo­phen­yl)diazen­yl]-2-hydr­oxy-3-methoxy­benzaldehyde

The title structure, C₁₄H₁₁BrN₂O₃, displays the characteristic features of azobenzene derivatives. The two aromatic rings are nearly coplanar, forming a dihedral angle of 8.71 (12)°. There is a strong intra­molecular O—H...O bond, and weak π–π and C—H...π inter­actions stabilize the structure.