(E)-2-[2-(2-Nitrophenyl)ethenyl]-8-quinolyl acetate

The title compound, C19H14N2O4, crystallizes with two molecules with very similar conformations in the asymmetric unit; the angles between the two ring systems are 8.7 (1) and 4.2 (1)°. In the crystal, intermolecular π–π interactions [centroid–centroid distance 3.973 (1) Å] lead to a three-dimensional network.

The title compound, C 19 H 14 N 2 O 4 , crystallizes with two molecules with very similar conformations in the asymmetric unit; the angles between the two ring systems are 8.7 (1) and 4.2 (1) . In the crystal, intermolecularinteractions [centroid-centroid distance 3.973 (1) Å ] lead to a threedimensional network. They have generated interest as a new class of potent HIV-1 integrase inhibitors (Mekouar et al., 1998), for modeling of the inhibition of retroviral integrases (Ouali et al., 2000), as protein tyrosine kinase inhibitors (Chen et al., 2002), as protozoal and retroviral co-infections (Fakhfakh et al., 2003), and as anti-HIV-1 agents (Storz et al., 2004). Zeng, Wang et al. (2006) reported that a series of 8-hydroxyquinoline derivatives with vinyl substituents at the 2-position could induce the proliferation of rMSCs (rat mesenchymal stem cells). With these findings, some analogs need to be synthesized for structure activity relationship research to find more potent molecules.
The molecular structure of the two molecules per asymmetric unit is illustrated in Fig. 2. In one molecule, the angle between the two ring systems is 8.7 (1)°; in the other it is 4.2 (1)°. In this crystal structure, the ethylenic bond lengths for C1-C2 and C26-C27 are 1.322 (5) and 1.329 (5) Å, respectively. The analogous bond reported by Zeng, OuYang et al.

Experimental
To a solution of 8-hydroxyquinaldine (1.19 g, 7.5 mmol) in acetic anhydride (5 ml) was added 2-nitrobenzaldehyde (1.12 g, 7.5 mmol). The mixture was heated under reflux for 11 h. After cooling, it was poured into ice water (50 ml) and stirred overnight. The yellow solid obtained was filtered and washed with water. The solid residue was recrystallized from CH 2 Cl 2 to afford the title compound (2.04 g, 75%). mp 143-144 °C. 20 mg was dissolved in 10 ml (EtOAc:petroleum ether 1:4) and the solution was kept at room temperature for 4 d. Natural evaporation gave orange single crystals suitable for X-ray analysis.

Refinement
All H atoms were positioned geometrically and refined using a riding model (including free rotation about the acetoxy C-C bond), with C-H = 0.95 Å (Csp 2 ) and 0.98 Å (methyl C); U iso (H) = kU eq (C), where k = 1.5 for methyl H atoms and 1.2 for all other H atoms. In the absence of significant anomalous scattering effects, Friedel pairs were merged.   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 Rfactors(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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )