(E)-2-{[1-(3,11-Dimethyl-4-methylene-10-oxo-1-phenyl-4,5,10,11-tetrahydro-1H-benzo[b]pyrazolo[3,4-f][1,5]diazocin-5-yl)ethylidene]amino}-N-methyl-N-(3-methyl-1-phenyl-1H-pyrazol-5-yl)benzamide

The central eight-membered ring of the title compound, C40H36N8O2, deviates from the ideal boat conformation because the bond between the exo-ethylene group and the adjacent N atom is twisted by 60.0 (4)° due to steric hindrance. Its adjacent benzene and pyrazole rings are oriented almost perpendicular to each other, making a dihedral angle of 85.8 (3)°. In the crystal, the molecules are linked by C(ar)—H⋯O hydrogen bonds, generating a three-dimensional network.

The central eight-membered ring of the title compound, C 40 H 36 N 8 O 2 , deviates from the ideal boat conformation because the bond between the exo-ethylene group and the adjacent N atom is twisted by 60.0 (4) due to steric hindrance. Its adjacent benzene and pyrazole rings are oriented almost perpendicular to each other, making a dihedral angle of 85.8 (3) . In the crystal, the molecules are linked by C(ar)-HÁ Á ÁO hydrogen bonds, generating a three-dimensional network.

Comment
We performed the Bischler-Napierlaski reaction (Plescia et al., 1979) on 2-acetamido-N-methyl-N-(3-methyl-1phenyl-1H-pyrazol-5-yl)benzamide by phosphorus oxychloride under reflux, obtaining an unexpected product related to a benzodiazocine system, whose corrected structure is now reported (Fig. 1). Single-crystal X-ray analysis on the reaction product allows to assign the formation of the title compound. The molecule crystallizes in a non-centrosymmetric space group: the possibility of the centrosymmetric space group C2/c was discounted by lack of a suitable solution and by the wholly satisfactory refinement in the space group Cc. The overall conformation of the molecular structure is determined by the central macrocycle formed by three fused cycles: a pyrazole, an eight-membered ring in the middle and a benzene.

Experimental
A mixture of 2-acetamido-N-methyl-N-(3-methyl-1-phenyl-1H-pyrazol-5-yl)benzamide (14.5 mmoles) and phosphorus oxychloride (50 ml) was refluxed for 1 h. Excess phosphorus oxychloride was evaporated under reduced pressure and the reaction mixture was poured into crushed ice mixed with solid sodium bicarbonate and extracted with chloroform (3x150 ml): the organic layers were washed with water, dried (sodium sulfate) and concentrated under reduced pressure to dryness to give a residue, which was crystallized from ethanol affording the title compound (yield 1.75 g).

Refinement
All non-H-atoms were refined anisotropically. Hydrogen atoms were located by difference Fourier synthesis, except methyl and phenyl hydrogen atoms, that were introduced at calculated positions, in their described geometries and allowed to ride on the attached carbon atom with fixed isotropic thermal parameters 1.2Ueq and 1.5Ueq of the parent supplementary materials sup-2 . E69, o1583 carbon atom for aromatic H-atoms and methyls H-atoms, respectively. For the methyls bound to the sp 2 -carbons, a rotating-group model was used. The crystal contains solvent accessible voids, however, no electron density peaks were found in chemically sensible positions for solvent molecules.

Figure 1
The molecular structure of the title compound, showing atom-labeling scheme. Displacement ellipsoids for non-H atoms are at the 50% probability level.

Data collection
Enraf-Nonius TurboCAD-4 diffractometer Radiation source: fine-focus sealed tube Graphite monochromator non-profiled ω/2θ scans 3952 measured reflections 3787 independent reflections 2014 reflections with I > 2σ(I) where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.15 e Å −3 Δρ min = −0.15 e Å −3 Absolute structure: Flack, 1983 Absolute structure parameter: 0.00 (2) 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.