2,2′,2′′-[(2,4,6-Trimethoxybenzene-1,3,5-triyl)tris(methylene)]tris(isoindole-1,3-dione)

The title molecule, C36H27N3O9, adopts an almost symmetric conformation in which the mean planes of the phthalimido units are inclined at dihedral angles of 81.1 (1), 85.3 (1) and 86.3 (1)° with respect to the plane of the central aromatic ring. The O atoms are involved in intra- and intermolecular C—H⋯O hydrogen bonding. The crystal structure also features π–π arene interactions [minimum ring centroid separation = 3.683 (2) Å]. The present mode of non-covalent interactions leads to a three-dimensional supramolecular architecture.

The title molecule, C 36 H 27 N 3 O 9 , adopts an almost symmetric conformation in which the mean planes of the phthalimido units are inclined at dihedral angles of 81.1 (1), 85.3 (1) and 86.3 (1) with respect to the plane of the central aromatic ring. The O atoms are involved in intra-and intermolecular C-HÁ Á ÁO hydrogen bonding. The crystal structure also features arene interactions [minimum ring centroid separation = 3.683 (2) Å ]. The present mode of non-covalent interactions leads to a three-dimensional supramolecular architecture.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZQ2198).

Jan-Ruven Rosien, Wilhelm Seichter and Monika Mazik Comment
Our interest in the title compound, C 36 H 27 N 3 O 9 , arises from its use as an important precursor in the synthesis of artificial receptors based on trimethoxybenzene-derived core (for a review on acyclic carbohydrate receptors containing a trimethyl-or triethylbenzene scaffold, see: Mazik, 2009). The title compound crystallizes in the space group P-1 with one molecule in the asymmetric part of the unit cell. The interplanar angles between the phthalimido residues are 6.67 (4) (B/C), 48.86 (3) (B/D) and 53.23 (3)° (C/D). According to the three-dimensional arrangement of substituents around the benzene ring the present conformational isomer can be named 1-up, 3,5-down tris(phthalimidomethyl), 2,4-up, 6-downtrimethoxybenzene. The molecular conformation is stabilized by seven C-H···O hydrogen bonds (Desiraju, 2002;Desiraju & Steiner, 1999;Mazik et al., 2001;Steiner, 2002)
Then the precipitate was suspended in water (150 ml), and the suspension was extracted with chloroform (3 x 100 ml).
The combined organic layers were washed with brine (100 ml) and water (100 ml), dried over magnesium sulfate and concentrated in vacuo. The desired product was obtained as a white solid after flash chromatography (SiO 2 , toluene/ethyl Suitable crystals of the title compound for X-ray analysis were obtained by slow evaporation of a CHCl 3 solution.

Computing details
Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); 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: SHELXTL (Sheldrick, 2008).  Perspective view of the title compound including the atom numbering. Anisotropic displacement parameters for nonhydrogen atoms are drawn at a 50% probability level.  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.