Crystal structure of (E)-3-(3,4-di­meth­oxy­phen­yl)-1-(1-hy­droxy­naphthalen-2-yl)prop-2-en-1-one

The mol­ecular structure of the title compound, C(21)H(18)O(4), consists of a 3,4-di­meth­oxy­phenyl ring and a naphthalene ring system linked via a prop-2-en-1-one spacer. The mol­ecule is almost planar, with a dihedral angle between the benzene ring and the naphthalene ring system of 2.68 (12)°. There is an intra­molecular O—H⋯O hydrogen bond involving the adjacent hy­droxy and carbonyl groups. The mol­ecule has an E conformation about the C=C bond and the carbonyl group is syn with respect to the C=C bond. In the crystal, mol­ecules are linked by bifurcated C—H⋯(O,O) hydrogen bonds, enclosing an R (2) (1)(6) ring motif, and by a further C—H⋯O hydrogen bond, forming undulating sheets extending in b- and c-axis directions. There are π–π inter­actions between the sheets, involving inversion-related naphthalene and benzene rings [inter­centroid distance = 3.7452 (17) Å], forming a three-dimensional structure.