Crystal structure of 1-benzyl-4-(2,4-dichlorophenyl)-2-imino-1,2,5,6,7,8,9,10-octahydrocycloocta[b]pyridine-3-carbonitrile

In the title compound, the cyclooctene ring adopts a twist chair–chair conformation. No directional interactions could be identified in the crystal and the packing is governed by van der Waals interactions.

In the title compound, C 25 H 23 Cl 2 N 3 , the cyclooctene ring adopts a twist chairchair conformation. The dihedral angles between the central pyridine ring (r.m.s. deviation = 0.013 Å ) and the pendant chlorobenzene and benzyl rings are 78.07 (11) and 87.47 (12) , respectively. No directional interactions could be identified in the crystal and the packing is governed by van der Waals interactions.

Chemical context
Synthetic and naturally occurring pyridine derivatives have a broad range of biological activities (Thorat et al., 2013), including anticancer and antimicrobial (Abdel-Megeed et al., 2012) and anticoagulant (de Candia et al., 2013) properties. They also have numerous applications in medicinal chemistry (Passannanti et al., 1998). The naturally occurring B6-vitamins pyridoxine, pyrodoxal, pyridoxamine and codecarbaxylase contain a pyridine nucleus (Shankaraiah et al., 2010). The study of the properties and the formation of imines is of great interest due to the role they play in several important chemical and biological processes (Larkin, 1990). Imines and their complexes have a variety of applications in biological, clinical and analytical fields (Singh et al., 1975;Patel et al., 1999). Many pyridine-2-one and 3-cyano-2-imino pyridine derivatives exhibit antiproliferative activity (McNamara & Cook, 1987;Abadi et al.,1998). As part of our ongoing studies of substituted pyridine systems (Vishnupriya et al., 2014a,b), we now describe herein the synthesis and crystal structure of the title compound, (I).

Supramolecular features
No short directional contacts are observed in the crystal structure of (I) and the packing is governed by van der Waals interactions.

Figure 2
Partial packing diagram of the title compound. For clarity, H atoms are not shown.

Refinement
C-bound H atoms were placed in calculated positions and allowed to ride on their carrier atoms, with C-H = 0.93 (aromatic CH) or 0.97 Å (methylene CH 2 ). Imine atom H1 was found in a difference map and refined freely, with the N-H distance restrained to 0.84 (2) Å . Isotropic displacement parameters for H atoms were calculated as U iso (H) = 1.2U eq (C) for CH and CH 2 groups, while the U iso factor for H1 was refined. Crystal data, data collection and structure refinement details are summarized in Table 1. 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: SHELXL2014/6 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: SHELXL2014/6 (Sheldrick, 2008).