1-{(1Z)-1-[3-(2,4-Dichlorophenoxy)propoxy]-1-(2,4-difluorophenyl)prop-1-en-2-yl}-1H-1,2,4-triazole

In the title compound, C20H17Cl2F2N3O2, the triazole ring makes dihedral angles of 28.0 (3) and 72.5 (2)° with the 2,4-dichloropheny and 2,4-difluorophenyl rings, respectively, and the molecule adopts a Z-conformation about the C=C double bond. In the crystal, C—H⋯O and C—H⋯N hydrogen bonds link the molecules.

In the title compound, C 20 H 17 Cl 2 F 2 N 3 O 2 , the triazole ring makes dihedral angles of 28.0 (3) and 72.5 (2) with the 2,4dichloropheny and 2,4-difluorophenyl rings, respectively, and the molecule adopts a Z-conformation about the C C double bond. In the crystal, C-HÁ Á ÁO and C-HÁ Á ÁN hydrogen bonds link the molecules.

Related literature
For a related structure and background to triazoles and further synthetic details, see: Shen et al. (2012).  Table 1 Hydrogen-bond geometry (Å , ).  In the molecular structure of the title compound the double bond is Z configurated. In the crystal, C-H···O and C-H···N hydrogen bonds link the molecules, in which they seem to be effective in the stabilization of the structure. (Table 1 and Experimental 3 g (0.01 mol) 1-(2,4-difluorophenyl)-2-(1,2,4-triazol)-1-y1)propan-1-one, 10 g of a 50% aqueous sodium hydroxide, 15 ml toluene and 1.5 ml of a 40% aqueous solution of tetrabutyl ammonium hydroxide are mixed and heated to 323.15 K under vigorous stirring. 2.8g (0.01 mol) 1-bromo-3-(2.4-dichlorophenoxy)-propane, dissolved in 10 ml toluene, is instilled into the stirred and warmed solution in the course of 10 h. The mixture is subsequently stirred for another 20 h at 323.15 K. The reaction mixture is mixed with as much water and chloroform so that the aqueous phase becomes lighter than the organic phase. Thereafter, the organic and aqueous phases are separated. The organic phase is dried with sodium sulfate. The solvents are distilled under reduced pressure. The impure product herein is subsequently crystallized from a 1:1 mixture of ethyl acetate and ethanol. The purified product may be analytically identified as an approximately pure Zisomer. Colourless blocks of the title compound were obtained by slow evaporation of an ethanol solution.

Refinement
H atoms were positioned geometrically with C-H = 0.93 and 0.97 Å for aromatic and methylene H atoms, respectively, constrained to ride on their parent atoms, with U iso (H) = 1.2 (or 1.5 for methyl groups) times U eq (C).  The molecular structure of the title molecule, with displacement ellipsoids drawn at 30% probability levels.  The packing diagram of the title compound. Hydron bonds are shown as dashed lines. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 1.21 e Å −3 Δρ min = −0.32 e Å −3

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq