2,9,12,15,18,25,27,34,37,40,43,50-Dodecaoxa-56-azaheptacyclo[24.24.5.151,55.03,8.019,24.028,33.044,49]hexapentaconta-3,5,7,19(24),20,22,28(33),29,31,44,46,48,51,53,55-pentadecaene

The title compound, C43H45NO12, was prepared from the reaction of 2,6-bis(dibromomethyl)pyridine and bisphenol in the presence of caesium carbonate as a base. The central ring makes dihedral angles of 64.83 (6), 13.48 (6), 56.96 (6) and 66.21 (6)° with the peripheral rings. In the crystal, molecules are linked by weak C—H⋯O and C—H⋯π interactions, forming a folded structure.

The title compound, C 43 H 45 NO 12 , was prepared from the reaction of 2,6-bis(dibromomethyl)pyridine and bisphenol in the presence of caesium carbonate as a base. The central ring makes dihedral angles of 64.83 (6), 13.48 (6), 56.96 (6) and 66.21 (6) with the peripheral rings. In the crystal, molecules are linked by weak C-HÁ Á ÁO and C-HÁ Á Á interactions, forming a folded structure.

Related literature
For background to crown ether-based macrocyclic compounds and their inclusion behaviour, see: Weber & Vö gtle, (1976, 1980. For the preparation and crystal structures of related compounds, see: Lee et al. (2009) Table 1 Hydrogen-bond geometry (Å , ).
Data collection: APEX2 (Bruker, 2000); cell refinement: SAINT-Plus (Bruker, 2000); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL  (Lee et al., 2009, Beack et al., 2012, we synthesized and reported the preparation and the solidstate structure of new crown ether bearing three aromatic subunits. As a part of our continuing interest in the development of new crown compounds, the preparation and crystal structure of new crown ether-based macrocyclic compound containing pyridine unit (Weber et al., 1976(Weber et al., , 1980, we report herein the crystal structure of the title compound. The crystal structure exhibits a twisted conformation with dihedral angles of 64.83 (6) Table 1; Cg1 and Cg2 are the centroids of the C7-C12 benzene ring and the N1/C1-C5 pyridine ring, respectively).

Experimental
To a refluxing suspension of caesium carbonate (14.1 mmol) in THF under nitrogen was added dropwise a solution of 2,6-bis(dibromomethyl)pyridine (2.82 mmol) and 1,8-bis(2-hydroxyphenoxy)-3,6-dioxaoctane (6.21 mmol) in THF over a period of 1 h. The mixture was then refluxed for an additional 48 h. After cooling to room temperature, 10% aqueous hydrochloric acid was added. The solvent was removed under reduced pressure and the residual mixture was extracted with dichloromethane. The organic layer was washed with water, dried over anhydrous magnesium sulfate, and evaporated in vacuo. The crude product was chromatographed on a silica-gel column using a mixed solvent of ethyl acetate and n-hexane (1:2) as eluent, and recrystallization from dichloromethane/n-hexane (1:30, v/v) gave as a crystalline solid in 24% yield (m.p. 402-404 K).

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.93 Å for aryl, 0.98 Å for methine, and 0.97 Å for methylene H atoms. U iso (H) = 1.2U eq (C) for all H atoms.

Data collection
Bruker APEXII CCD diffractometer Radiation source: fine-focus sealed tube Graphite monochromator π and ω scans Absorption correction: multi-scan (SADABS; Sheldrick, 1996) T min = 0.975, T max = 0.988 33651 measured reflections 8622 independent reflections 7657 reflections with I > 2σ(I)  443, 151.085, 146.497, 137.688, 124.763, 122.382, 121.690, 114.131, 104.316, 71.976, 70.049, 69.576 p.p.m.. 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.