4-((E)-{2-[N-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)carboximidoyl]benzylidene}amino)-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one

The title compound, C30H28N6O2, is a symmetric diimine derived from ortho-dibenzaldehyde. Both C=N bonds are (E)-configured. The terminal N-bonded phenyl groups adopt staggered conformations relative to their respective parent heterocycles, the relevant least-squares planes intersect at angles of 32.35 (11) and 38.59 (10)°. In the crystal, C—H⋯O contacts connect the molecules into chains along the b axis and give rise to a C 1 1(14)C 1 1(14) and a R 2 2(12) pattern on different levels of graph-set analysis. The shortest intercentroid distance between two centroids was found at 4.2074 (11) Å between the two five-membered heterocycles.

The title compound, C 30 H 28 N 6 O 2 , is a symmetric diimine derived from ortho-dibenzaldehyde. Both C N bonds are (E)-configured. The terminal N-bonded phenyl groups adopt staggered conformations relative to their respective parent heterocycles, the relevant least-squares planes intersect at angles of 32.35 (11) and 38.59 (10) . In the crystal, C-HÁ Á ÁO contacts connect the molecules into chains along the b axis and give rise to a C 1 1 (14)C 1 1 (14) and a R 2 2 (12) pattern on different levels of graph-set analysis. The shortest intercentroid distance between two centroids was found at 4.2074 (11) Å between the two five-membered heterocycles.

Related literature
For the crystal structure of another diimine capable of acting as a chelate ligand, see: Yumata et al. (2011). For graph-set analysis of hydrogen bonds, see: Etter et al. (1990); Bernstein et al. (1995). For details on puckering analysis, see: Cremer & Pople (1975). For general information about the chelate effect, see: Gade (1998 Table 1 Hydrogen-bond geometry (Å , ). Both C=N double bonds are (E)-configured. The least-squares planes defined by the five-membered heterocycles on the one hand and the central phenyl moiety on the other hand enclose angles of 3.16 (10) and 4.47 (10)°, respectively.
The nitrogen-bonded phenyl moieties adopt staggered conformations relative to their respective parent heterocycles, the relevant least-squares planes intersect at angles of 32.35 (11) and 38.59 (10)°. A conformation analysis of the five-membered heterocycles (Cremer & Pople, 1975) is invariably precluded by the small puckering amplitude (Fig. 1).
In the crystal, C-H···O contacts whose range falls by more than 0.1 Å below the sum of van-der-Waals radii are present.
These are observed between H atoms of the methyl groups and the ketonic O atoms. In terms of graph-set analysis (Etter et al., 1990;Bernstein et al., 1995), the descriptor for these interactions is C 1 1 (14)C 1 1 (14) on the unitary level and emphasizes the presence of two antidromic chains whereas a R 2 2 (12) descriptor on the binary level highlights the existence of cyclic patterns. In total, the molecules are connected to infinite chains along the crystallographic b axis. The shortest intercentroid distance between two centers of gravity was found at 4.2074 (11) Å (Fig. 2).
The packing of the title compound in the crystal is shown in Figure 3.

Experimental
A solution of 0.99 g of phthalaldehyde in 20 cm 3 of methanol was added dropwise to a stirred solution of 3.00 g of 4aminoantipyrine in 30 cm 3 of methanol. The solution was refluxed under nitrogen for 15 minutes. Upon cooling, a yellow precipitate formed which was filtered and dried under reduced pressure. The product was recrystallized from methanol to produce yellow crystals.