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

The synthesis, mol­ecular X-ray structure and in silico EGFR and HER2 mol­ecular docking studies are reported for 4-hy­droxy-3,5-di­meth­oxy­benzaldehyde (6-chloro­pyridazin-3-yl)hydrazone hydrate, which constitutes a new pyridazine-based compound incorporating a syringaldehyde moiety by condensation of the hydrazine linker with the aldehyde function.

In the title compound, C₁₃H₁₃ClN₄O₃·H₂O, the organic mol­ecule has an E 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 mol­ecule comparably flat. A C—H⋯N hydrogen bond generates an inversion dimer with a large R₂²(14) ring motif. Within this ring, a further C—H⋯N hydrogen bond establishes a smaller R₂²(8) ring. The mol­ecules 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 meth­oxy oxygen atoms of an adjacent mol­ecule, leading to the formation of an R₂¹(5) membered ring. C—H⋯π and face-to-face π–π stacking inter­actions are also present in the two-dimensional framework, which may be of relevance for the packing. In a complementary analysis, the compound was docked in silico to EGFR and HER2 receptors and the results imply that the compound targets EGFR preferentially over HER2.