Crystal structure and Hirshfeld surface analysis of 5-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-phenyl-4,5-dihydro-1H-pyrazole-1-carboxamide

In the title compound, the mean plane of the central pyrazole ring [r.m.s. deviation = 0.095 Å] makes dihedral angles of 11.93 (9) and 84.53 (8)°, respectively, with the phenyl and benzene rings. In the crystal, pairs of N—H⋯O hydrogen bonds link inversion-related molecules into dimers, generating an (8) ring motif.

In the title compound, C 24 H 31 N 3 O 2 , the mean plane of the central pyrazole ring [r.m.s. deviation = 0.095 Å ] makes dihedral angles of 11.93 (9) and 84.53 (8) , respectively, with the phenyl and benzene rings. There is a short intramolecular N-HÁ Á ÁN contact, which generates an S(5) ring motif. In the crystal, pairs of N-HÁ Á ÁO hydrogen bonds link inversion-related molecules into dimers, generating an R 2 2 (8) ring motif. The Hirshfeld surface analysis indicates that the most significant contribution involves HÁ Á ÁH contacts of 68.6%
The Hirshfeld surface analysis (Spackman & Jayatilaka, 2009) was generated by CrystalExplorer17 (Turner et al., 2017) and comprises d norm surface plots and two-dimensional fingerprint plots (Spackman & McKinnon, 2002). A d norm surface plot of the title compound mapped using a standard surface resolution with a fixed colour scale of À0.5426 (red) to 1.7721 a.u. (blue) is shown in Fig. 3. The dark-red spots on the d norm surface arise as a result of the N-HÁ Á ÁO hydrogen bonds (Table 1), while the other weaker intermolecular interactions appear as light-red spots. The bright-red spots indicate their roles as the respective donors and/or acceptors; they also appear as blue and red regions corresponding to positive and negative potentials on the Hirshfeld surfaces mapped over electrostatic potential (Spackman et al., 2008;Jayatilaka et al., 2005), as shown in Fig. 4.
The shape-index of the Hirshfeld surface is a tool to visualizestacking interactions by the presence of adjacent red and blue triangles; if there are no adjacent red and/or blue 1468 Ayten R. Asgarova  Symmetry code: (i) Àx þ 2; Ày þ 1; Àz þ 1.

Figure 3
View of the three-dimensional Hirshfeld surface of the title compound mapped over d norm , in the range À0.5426 to 1.7721 au.

Figure 1
The molecular structure of the title compound, with the atom labelling. Displacement ellipsoids are drawn at the 30% probability level.

Synthesis and crystallization
To a solution of of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)-1phenylprop-2-en-1-one (1.2 mmol) in 10 ml ethanol was added semicarbazide hydrochloride (1.26 mmol). The mixture was refluxed for 3 h and then cooled to room temperature. The title compound, that precipitated as colourless single crystals, was collected by filtration and washed with an ethanol-water Hirshfeld surface of the title compound mapped over the shape-index.  View of the three-dimensional Hirshfeld surface of the title compound mapped over the electrostatic potential energy in the range À0.0500 to 0.0500 a.u. using the STO-3 G basis set at the Hartree-Fock level of theory. Hydrogen-bond donors and acceptors are shown as blue and red regions around the atoms corresponding to positive and negative potentials, respectively.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. Hydrogen atoms of the amino group were located in a difference-Fourier map and refined freely. The hydroxy H atom (H15) was included in the calculated position (AFIX 147; O-H = 0.84 Å ) and refined with U iso (H) = 1.5U eq (O). All the C-bound H atoms were placed in calculated positions and refined using a riding model: C-H = 0.95-1.00 Å with U iso (H) = 1.2U eq (C).
As reported previously (   program(s) used to solve structure: SHELXT2014 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018/3 (Sheldrick, 2015b); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: PLATON (Spek, 2009).  (10) Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.