8-[(3-Phenyl-1,2,4-oxadiazol-5-yl)methoxy]quinoline monohydrate

In the title compound, C18H13N3O2·H2O, the oxadiazole ring forms dihedral angles 7.21 (10) and 21.25 (11)° with the quinoline and benzene rings, respectively. The crystal structure features O—H⋯N hydrogen bonds and is further consolidated by C—H⋯O hydrogen-bonding interactions involving the water molecule of hydration.

In the title compound, C 18 H 13 N 3 O 2 ÁH 2 O, the oxadiazole ring forms dihedral angles 7.21 (10) and 21.25 (11) with the quinoline and benzene rings, respectively. The crystal structure features O-HÁ Á ÁN hydrogen bonds and is further consolidated by C-HÁ Á ÁO hydrogen-bonding interactions involving the water molecule of hydration.

Related literature
For general background, see: Katritzky et al. (1992). For preparation of the title compound, see: Shishue & Henry (1989). For crystal structure of a related compound, see: Liu et al. (2006).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PV2633). Due to unique biological activity in medicine and pesticide, 1,2,4-oxadiazole derivatives have received an increased attention. It plays an increasingly important role in pharmaceutical synthesis, if different heterocyclics were introduced into 1,2,4-oxadiazole ring (Katritzky et al., 1992). We have synthesized the title compound which is a novel derivative of 1,2,4-oxadiazole. In this article, we describe the synthesis and crystal structure of the title compound.
In the title molecule ( Fig. 1) the bond distances and bond angles agree very well with the corresponding bond distances and angles reported in a closely related compound (Liu et al., 2006). The quinoline ring is essentially planar (rmsd = 0.0118 Å). The oxadiazole ring forms dihedral angles 7.21 (10)
The reaction mixture was stirred at refluxing condition for about 5 h. After being cooled to room temperature, the mixture was filtered and evaporated in vacuo. The crude product was further recrystallized from ethyl acetate to give white solid (yield = 2.26 g; 75%). Crystals suitable for X-ray crystallographic studies were grown by slow evaporation of ethyl acetate solution.

Refinement
H atoms were positioned geometrically, with C-H = 0.93, 0.97 and 0.96 Å for aromatic, methylene and methyl H, respectively, and constrained to ride on their parent atoms, with U iso (H) = xU eq (C,N), where x = 1.5 for methyl H and x = 1.2 for all other H atoms. The H-atoms of the water of hydration were located from a difference map and were allowed to refine with U iso (H) = 1.5U eq (O).

Computing details
Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf-Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: PLATON (Spek, 2009  The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Special details 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.