2,4,6,8-Tetrakis(2-methoxyphenyl)-3,7-diazabicyclo[3.3.1]nonan-9-one diethyl ether hemisolvate

In the title compound, C35H36N2O5·0.5C4H10O, the asymmetric unit contains one bicyclo[3.3.1]nonane molecule and a half-occupancy diethyl ether solvent with the O atom lying on a crystallographic inversion center. Two intramolecular N—H⋯O hydrogen bonds generate S(6) ring motifs. The bicyclo[3.3.1]nonane ring system adopts a chair-boat conformation. In the crystal structure, the molecules are linked by weak intermolecular C—H⋯N hydrogen bonds into chains along the b axis; additional stabilization is provide by C—H⋯π interactions.

In the title compound, C 35 H 36 N 2 O 5 Á0.5C 4 H 10 O, the asymmetric unit contains one bicyclo[3.3.1]nonane molecule and a half-occupancy diethyl ether solvent with the O atom lying on a crystallographic inversion center. Two intramolecular N-HÁ Á ÁO hydrogen bonds generate S(6) ring motifs. The bicyclo[3.3.1]nonane ring system adopts a chair-boat conformation. In the crystal structure, the molecules are linked by weak intermolecular C-HÁ Á ÁN hydrogen bonds into chains along the b axis; additional stabilization is provide by C-HÁ Á Á interactions.

Related literature
For applications of bicyclo[3.3.1]nonane derivatives, see: Arias-Perez et al. (1997). For applications of N,N-diphenyl derivatives, see: Srikrishna & Vijayakumar (1998). For bicyclic systems with aryl groups, see: Vijayakumar et al. (2000). For ring conformations, see: Cremer & Pople (1975). For hydrogen-bond motifs, see: Bernstein et al. (1995). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986).  Table 1 Hydrogen-bond geometry (Å , ). (ii) Àx; Ày þ 2; Àz þ 1; (iii) Àx þ 1; Ày þ 2; Àz þ 2. Cg1 and Cg2 are the centroids of the C12-C17 and C19-C24 benzene rings, respectively. Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; 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 and PLATON (Spek, 2009 (Arias-Perez el al., 1997). Functionalized 3-azabicyclo[3.3.1]nonanes have been studied intensively because of their pharmaceutical use and these compounds find applications as an important class of organic compounds in the field of molecular recognition. The 1,5-diphenyl-3,7-diazabicyclo[3.3.1]nonan-9-ones are local anaesthetics. Some of them have hypotensive activity. N,N-diphenyl derivatives are found to possess antiphogistic and anti-thrombic activities (Srikrishna & Vijayakumar, 1998). The synthesis and stereochemistry of 3,7-diazabicyclo[3.3.1]nonan-9-ones and their derivatives are of much interest due to their diverse biological activities, such as antibacterial, antifungal, antiarrhythmic, antiphologistic, antithrombic, calcium antagonistic, hypotensive and neuroleptic properties and also because of their presence in naturally occurring lupin alkaloids. The conformational analysis of 3,7-diazabicyclo[3.3.1]nonanes (bispidines) is of considerable interest both from the theoretical view point and due to their biological activity. In recent years the 2,4,6,8-tetraaryl-3,7-diazabicyclo[3.3.1]nonanes constitutes an interesting case for study because of the presence of four aryl groups. If all the aryls are in equatorial orientations, molecular models indicate close proximity of the aryls in both rings in the bicyclic systems (Vijayakumar el al., 2000). If they are in the twin chair conformation, it causes severe non-bonded interactions between aryl groups in 2,8-positions and 4,6-positions. So in order to attain the stability, the system may exist in the twin chair conformations and the aryls may assume different orientations in order that the overall stability can be attained. Hence these systems constitute an interesting case for study.

Crystal data
In the title compound ( Fig. 1), the asymmetric unit contains one bicyclo[3.3.1]nonane molecule and a half-occupied diethyl ether solvent with the oxygen atom of diethyl ether molecule lying on the crystallographic inversion center (1/2, 1/2, 0).
In the crystal structure, the molecules are linked by intermolecular C4-H4A···N2 hydongen bonds into one-dimensional chains along the b axis. The molecules are also stabilized by the C-H···π interactions.

Experimental
A mixture of acetone (0.68 ml), 2-methoxybenzaldehyde (5 g) and dry ammonium acetate (1.4 g) was taken in 1:4:2 molar ratio in ethanol and it were heated on water bath till the colour changes to reddish orange. The mixture was allowed to supplementary materials sup-2 stand for 24 h resulting in the formation of a sticky substance. To that diethyl ether was added and warmed gently. The fine needle-shaped crystals were separated out from the reaction mixture upon slow evaporation of the solvent. The purity of the compound was checked by TLC. Yield: 53%. M.p. 507 K.

Refinement
N-bound hydrogen atoms were located from the difference Fourier map and refined riding on their parent atom with U iso (H) = 1.2U eq (N). The rest of the hydrogen atoms were positioned geometrically [C-H = 0.9300-0.9800 Å] and refined using a riding model, with U iso (H) = 1.2U eq (C) and 1.5U eq (methyl C). A rotating group model was used for the methyl groups excepting for those in the solvent molecule. Fig. 1. The molecular structure of the title compound with atom labels and 30% probability ellipsoids for non-H atoms. Atoms labelled with suffix B are generated by symmetry code (x + 1, -y + 1, -z + 2). Intramolecular hydrogen bonds are shown in as dashed lines. Hydrogen atoms of the solvent molecules have been omittted for clarity.  0.0140 (4) 0.0125 (4) 0.0120 (4) 0.0023 ( 0.0351 (7) 0.0133 (5) 0.0418 (7