14-Methoxy-4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diazatetracyclo[8.8.0.02,7.013,18]octadeca-2(7),13,15,17-tetraene-3,5,11-trione

The title compound, C23H20N2O6, crystallizes with two molecules in the asymmetric unit in which the dihedral angles between the mean planes of the pyran and phenyl rings are 66.6 (1) and 61.9 (1) °. The fused pyrone and pyran rings each adopts a sofa conformation. In the crystal, C—H⋯O hydrogen bonds link the molecules, forming a two-dimensional network parallel to [001].

The title compound, C 23 H 20 N 2 O 6 , crystallizes with two molecules in the asymmetric unit in which the dihedral angles between the mean planes of the pyran and phenyl rings are 66.6 (1) and 61.9 (1) . The fused pyrone and pyran rings each adopts a sofa conformation. In the crystal, C-HÁ Á ÁO hydrogen bonds link the molecules, forming a two-dimensional network parallel to [001].
We have already reported a similar compound (Jagadeesan et al., 2013). The title compound crystallizes with two molecules in the asymmetric unit. Geometrical parameters are almost similar the title compound and the previously reported structure. The six-membered pyrone and pyran rings adopt a sofa conformation. The dihedral angle between the mean planes of the pyran and phenyl rings is 66.6 (1) ° and 61.9 (1) ° for the molecule A and B respectively. The crystal packing is stabilized by C-H···O intermolecular hydrogen bonds ( Fig. 2 and Table 1).

Experimental
A mixture of 2-ethoxy-6-formylphenyl (2E)-but-2-enoate (0.234 g, 1 mmol) and N,N-dimethylbarbituric acid (0.156 g, 1 mmol) was placed in a round bottom flask and melted at 180 °C for 1 h. After completion of the reaction as indicated by TLC, the crude product was washed with 5 ml of ethylacetate and hexane mixture (1:49 ratio) which successfully provided the pure product in 90% yield as colorless solid. Diffraction quality crystals were obtained by slow evaporation of a solution in (Methonal and ethanol)6:4 ratio.
The methyl groups bonded to N were refined as disordered over two equally occupied sites rotated by 60 degrees.   The molecular structure of the title compound. Displacement ellipsoids are drawn at the 30% probability level, H atoms have been omitted for clarity.

Computing details
Δρ min = −0.18 e Å −3 Extinction correction: SHELXL97 (Sheldrick, 2008), Fc * =kFc[1+0.001xFc 2 λ 3 /sin(2θ)] -1/4 Extinction coefficient: 0.0041 (7) 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.