N′-[(5-Methyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)(thiophen-2-yl)methylidene]benzohydrazide

In the title compound, C22H18N4O2S, the seven-membered ring generated by an intramolecular N—H⋯O hydrogen bond adopts an envelope conformation in both of the two independent molecules in the asymmetric unit. In the crystal, molecules are linked into C(9) chains along [100] by N—H⋯O hydrogen bonds. The molecules are also weakly linked by C—H⋯O and C—H⋯N interactions, forming dimers with edge-connected R 2 2(9) rings. The dimers are interlinked by further weak C—H⋯N hydrogen bonds into chains along [010].

In the title compound, C 22 H 18 N 4 O 2 S, the seven-membered ring generated by an intramolecular N-HÁ Á ÁO hydrogen bond adopts an envelope conformation in both of the two independent molecules in the asymmetric unit. In the crystal, molecules are linked into C(9) chains along [100] by N-HÁ Á ÁO hydrogen bonds. The molecules are also weakly linked by C-HÁ Á ÁO and C-HÁ Á ÁN interactions, forming dimers with edge-connected R 2 2 (9) rings. The dimers are interlinked by further weak C-HÁ Á ÁN hydrogen bonds into chains along [010].
anticancer (Zhang et al.,2007) and antimalarial (Gemma et al.,2006). The hydrazones are also important for their use as plasticizers and stabilizers for polymers, polymerization initiators, antioxidants and as indicators (Gupta et al., 2007).
Derivatives of 1-phenyl-3-methyl-4-acyl-5-pyrazolone have found extensive application in coordination chemistry (Shi et al., 2005) and in antibacterial activation (Zhang et al., 2008;Li et al., 2000). Recently, a large number of hydrazone compounds have been reported (Qiu, 2009;Ren et al., 2009). The possible properties and using of hydrazones and the pyrazolone derivatives make it attractive to study these compounds.
The molecular structure of the title compound is shown in Fig. 1. There are two kinds of molecules in the asymmetric unit, which partly differ from each other geometrically. For example, the distance being 1.925 (15) Å between H4A and O1 of the hydrogen bond N4-H4A···O1 in the first kind of molecules is longer than that of the hydrogen bond N8-H8A···O3 in the second kind of molecules which is 1.855 (13) Å. In each independent molecule, the seven-membered ring generated by the intramolecular N-H···O hydrogen bond adopts an envelope conformation. The coplanar atom O1,C7,C8, C11(with the largest deviation of -0.0229 (23) Å for atom C8) and the coplanar atom O3,C29,C30, C33(with the largest deviation of -0.0061 (22) Å for atom C29) form the mean planes of the envelopes, the mean planes and the bonded pyrazole ring are essentially planar, with the dihedral angle of 4.26 (11) ° and 0.56 (9) ° respectively. Plane of N3,N4, H4A and Plane of N7,N8, H8A form the up-warping parts of the envelopes, making a dihedral angle of 61.07 (9)° and 63.20 (98)° with the corresponding mean planes respectively. The pyrazole rings of the two molecules make dihedral angles of 23.16 (8)°, 58.23 (8)°, 31.23 (7)° and 20.06 (7)°, 52.36 (8)°, 20.46 (7)° with the benzene ring of pyrazolone, the thiophen ring and benzene ring of benzoyl hydrazine, respectively.

Experimental
The title compound was synthesized by refluxing the mixture of 1-phenyl-3-methyl-4-(2-thenoyl)pyrazolone-5 (30m mol) and benzoyl hydrazine (30m mol) in ethanol (150 ml) over a steam bath for about 6 h, then the solution was cooled down to room temperature. After seven days, pale yellow block was obtained and dried in air. The product was recrystallized from ethanol which afforded pale yellow crystals suitable for X-ray analysis.

Refinement
During refinement, all H atoms were geometrically positioned and treated as riding on their parent atoms, with C-H = 0.93 Å for the aromatic, 0.96 Å for the methyl and N-H= 0.86 Å with U iso (H)= 1.2 U eq (Caromatic, N) or, 1.5U eq (Cmethyl).

Figure 1
The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are presented as a small spheres of arbitrary radii. The hydrogen-bond is shown in dash line.

Figure 3
The three-dimensional structure linked by the weak interactions (shown in dash lines)   (6) Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 R-factors(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.