Crystal structure of 5-(4-methoxyphenyl)-3-(4-methylphenyl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde

In the title compound, C18H18N2O2, the pyrazole ring has a twisted conformation on the CH—CH2 bond. The tolyl ring and the 4-methoxyphenyl ring are inclined to the mean plane of the pyrazole ring by 4.40 (9) and 86.22 (9)°, respectively, while the two aromatic rings are inclined to one another by 88.75 (9)°. In the crystal, molecules are linked via bifurcated C—H⋯(O,O) hydrogen bonds and C—H⋯π interactions, forming sheets lying parallel to the ab plane.

Cg2 is the centroid of the C1-C6 ring.
The molecular structure of the title compound is illustrated in Fig. 1. The pyrazole ring has a twisted conformation on bond C7-C8. The toluyl ring and the 4-methoxyphenyl ring are inclined to the mean plane of the pyrazole ring by 4.40 (9) and 86.22 (9) °, respectively. The two aromatic rings are inclined to one another by 88.75 (9) °.
In the crystal, molecules are linked via C-H···O hydrogen bonds and C-H···π interactions forming sheets lying parallel to the ab plane (Table 1 and Fig. 2).

S3. Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. The hydrogen atoms were fixed geometrically (C-H = 0.95-1.00 Å) and allowed to ride on their parent atoms with U iso (H) = 1.5U eq (C-methyl) and 1.2U eq (C) for other H atoms.
supporting information

Figure 1
A view of the molecular structure of the title compound, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

Figure 2
A view along the ab axis of the crystal packing of the title compound. Hydrogen bonds are shown as dashed lines (see Table 1).