5-Benzoyl-N,4-diphenyl-4,5-dihydro-1H-pyrazole-3-carboxamide

The title compound, C23H19N3O2, was synthesized by the 1,3-dipolar cycloaddition reaction of N-phenyl-α-diazoacetamide and chalcone. In the molecule, the pyrazoline ring assumes an envelope conformation. Weak intermolecular C—H⋯O hydrogen bonding is present in the crystal structure.

The title compound, C 23 H 19 N 3 O 2 , was synthesized by the 1,3dipolar cycloaddition reaction of N-phenyl--diazoacetamide and chalcone. In the molecule, the pyrazoline ring assumes an envelope conformation. Weak intermolecular C-HÁ Á ÁO hydrogen bonding is present in the crystal structure.

Experimental
The molecular structure of (I) is shown in Fig. 1. In the molecule the dihydropyrazole ring assumes an envelope conformation. The C6-benene ring and C15-benene ring make dihedral angles of 82.08 (7)° and 84.78 (7)° with respect to the C23-benene ring. The dihedral angle between the C6-benzene and C15-benene ring is 71.39 (7)°. Intermolecular weak C-H···O hydrogen bonding is present in the crystal structure (Table 1).
Experimental N-Phenyl-alfa-diazoacetamide (0.035 g, 0.2 mmol) and chalcone (0.042 g, 0.2 mmol) and 1,4-diaza-bicyclo[2.2.2]octan (0.02 g, 0.2 mmol) were dissolved in toluene (2 mL). The solution was warmed to 323 K, and the solution was stirred for 2 h. After removal of solvent under reduced pressure, the residue was purified through column chromatography on silica gel to give target compound. Colourless single crystals suitable for X-ray diffraction were obtained by recrystallization from ethanol.

Refinement
Imino H atoms were located in a difference Fourier map and were refined isotropically. Other H atoms were placed in calculated positions with C-H = 0.93 or 0.98 Å, and refined using a riding model, with U iso (H) =1.2U eq (C). Fig. 1. The molecular structure of (I) with 30% probability displacement ellipsoids (arbitrary spheres for H atoms).

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.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.