Crystal structure and Hirshfeld surface analysis of 4-(4-methylbenzyl)-6-phenylpyridazin-3(2H)-one

In this paper, we describe the synthesis of a new dihydro-2H-pyridazin-3-one derivative. The molecule, C18H16N2O, is not planar; the benzene and pyridazine rings are twisted with respect to each other, making a dihedral angle of 11.47 (2)°, and the toluene ring is nearly perpendicular to the pyridazine ring, with a dihedral angle of 89.624 (1)°. The molecular conformation is stabilized by weak intramolecular C—H...N contacts. In the crystal, pairs of N—H...O hydrogen bonds link the molecules into inversion dimers with an R22(8) ring motif. The intermolecular interactions were investigated using Hirshfeld surface analysis and two-dimensional (2D) fingerprint plots, revealing that the most important contributions for the crystal packing are from H...H (56.6%), H...C/C...H (22.6%), O...H/H...O (10.0%) and N...C/C...N (3.5%) interactions.