Crystal structure of methyl 6-methoxy-11-(4-methoxyphenyl)-16-methyl-14-phenyl-8,12-dioxa-14,15-diazatetracyclo[8.7.0.02,7.013,17]heptadeca-2(7),3,5,13(17),15-pentaene-10-carboxylate

In the title compound, the pyran and pyrone rings adopt slightly distorted half-chair and envelope conformations, respectively. In the crystal, C—H⋯O and π–π interactions connect the molecules, forming double layers that stack along the c-axis direction.


Chemical context
Chromenes are components of many natural products (Ellis & Lockhart, 2007) and incorporated in numerous medicinal drugs as significant chromophores. They have shown to display antiviral, antitumoral, anti-anaphylactic, spasmolytic, diuretic and clotting activity (Horton et al., 2003). Furthermore, they can be used as photo-active materials, biodegradable agrochemicals and pigments. As part of our studies in this area, the crystal structure of the title compound has been determined and the results are presented here. Fig. 1 shows a displacement ellipsoid plot of the title compound, with the atom-numbering scheme. The pyran ring ISSN 1600-5368 (O1/C1/C3/C4/C5/C13) adopts a slightly distorted half-chair conformation, with the local twofold rotation axis running through the mid-points of bonds C3-C1 and C5-C4 [asymmetry parameter (Duax et al., 1976) ÁC 2 [C3-C1] = 7.5 (2) ] The pyrone ring (O2/C5/C6/C7/C12/C13) adopts an envelope conformation, with the C5 [displacement = 0.347 (1) Å ] atom as the flap and with puckering parameters q 2 = 0.3973 (2) Å and ' 2 = 119.7 (2) . The pyrazole ring is approximately planar, with a maximum deviation of 0.002 (2) Å for atom C2, and forms a dihedral angle of 13.2 (1) with the attached benzene ring. The planar atoms of the pyran ring and the pyrazole ring are close to coplanar, the dihedral angles between their mean planes being 6.4 (1) . Moreover, the planar atoms of the pyrone ring and the benzene ring of the chromene unit are also almost coplanar, the dihedral angle between their mean planes being 10.7 (1) .

Structural commentary
The geometric parameters of the title molecule agree well with those reported for similar structures (Kanchanadevi et al., 2013a,b).

Figure 2
A view of stacking of supramolecular double layer along the c axis. The C-HÁ Á ÁO andinteractions are shown as green and blue dotted lines, respectively. Table 1 Hydrogen-bond geometry (Å , ).

Synthesis and crystallization
A mixture of (E)-methyl 2-[(2-formyl-6-methoxyphenoxy)methyl]-3-(4-methoxyphenyl)acrylate (0.356g, 1mmol) and 3-methyl-1-phenyl-1H-pyrazol-5-one (0.174 g, 1 mmol) was placed in a round-bottomed flask and melted at 453 K for 1 h. After completion of the reaction as indicated by thin-layer chromatography, the crude product was washed with 5 ml of an ethyl acetate and hexane mixture (1:49 ratio), which successfully provided the title compound as a colourless solid in 93% yield. Colourless blocks were obtained by slow evaporation of an ethyl acetate solution at room temperature.

Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2. All the H atoms were positioned geometrically, with C-H = 0.93-0.98 Å , and constrained to ride on their parent atom, with U iso (H) = 1.5U eq (C) for methyl H atoms and 1.2U eq (C) for other H atoms. Owing to poor agreement, the reflections 100, 011 and 100 were omitted from the final cycles of refinement.

Computing details
Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009). where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.19 e Å −3 Δρ min = −0.14 e Å −3 Extinction correction: SHELXL97 (Sheldrick, 2008), Fc * =kFc[1+0.001xFc 2 λ 3 /sin(2θ)] -1/4 Extinction coefficient: 0.0075 (7) 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 > 2sigma(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.