Synthesis, crystal structure, and <i>in silico</i> molecular docking studies of 4-hydroxy-3,5-dimethoxybenzaldehyde (6-chloropyridazin-3-yl)hydrazone monohydrate

In the title compound, C₁₃H₁₃ClN₄O₃·H₂O, the organic mol-ecule has an <i>E</i> configuration with regard to the C=N bond of the hydrazone bridge. The phenyl and pyridazine rings subtend a dihedral angle of 2.1 (1)° between their mean planes, while the hydrazone moiety makes dihedral angles of 1.6 (2) and 3.0 (2)°, respectively, with these aromatic rings. This renders the entire mol-ecule comparably flat. A C-H⋯N hydrogen bond generates an inversion dimer with a large <i>R</i> ₂ ²(14) ring motif. Within this ring, a further C-H⋯N hydrogen bond establishes a smaller <i>R</i> ₂ ²(8) ring. The mol-ecules of a dimer are thereby firmly linked by four hydrogen bonds. A bifurcated O-H⋯(O,O) hydrogen bond is formed between a water hydrogen atom and the hydroxyl and meth-oxy oxygen atoms of an adjacent mol-ecule, leading to the formation of an <i>R</i> ₂ ¹(5) membered ring. C-H⋯π and face-to-face π-π stacking inter-actions are also present in the two-dimensional framework, which may be of relevance for the packing. In a complementary analysis, the compound was docked <i>in silico</i> to EGFR and HER2 receptors and the results imply that the compound targets EGFR preferentially over HER2.