1-[(Z)-8-(4-Chlorophenoxy)-3-(2,4-difluorophenyl)-4-oxaocta-2-en-2-yl]-1H-1,2,4-triazol-4-ium nitrate

In the title compound C21H21ClF2N3O2 +·NO3 −, the triazole ring makes dihedral angles of 40.7 (3) and 30.2 (4)° with the 4-chloropheny and 2,4-difluorophenyl rings, respectively. The cation adopts a Z-configuration about the C=C double bond which links the triazole ring to the 4-chlorophenoxy unit via a butyloxy chain. In the crystal, the cations and the anions are linked by N—H⋯O, C—H⋯O and C—H⋯F hydrogen bonding.

In the title compound C 21 H 21 ClF 2 N 3 O 2 + ÁNO 3 À , the triazole ring makes dihedral angles of 40.7 (3) and 30.2 (4) with the 4chloropheny and 2,4-difluorophenyl rings, respectively. The cation adopts a Z-configuration about the C C double bond which links the triazole ring to the 4-chlorophenoxy unit via a butyloxy chain. In the crystal, the cations and the anions are linked by N-HÁ Á ÁO, C-HÁ Á ÁO and C-HÁ Á ÁF hydrogen bonding.
In the title compound ( Fig. 1), the cation adopts a Z conformation about the C═C double bond. In the crystal structure the anions and cations are connected via N-H···O, C-H···O and C-H···F hydrogen bonding (Table 1 and Fig. 2).
Experimental 1-(2,4-Difluorophenyl)-2-(1,2,4-triazol)-1-y1)propan-1-one (3.0 g, 0.01 mol) 10 g of a 50% aqueous sodium hydroxide, toluene (15 ml) and 1.5 ml of a 40% aqueous solution of tetrabutyl ammonium hydroxide were mixed and heated to 323 K under vigorous stirring. 1-Bromo-4-(4-chlorophenoxy)-butane (2.6 g, 0.01 mol) dissolved in 10 ml toluene, was instilled into the stirred and warmed solution in the course of 10 h. The mixture was subsequently stirred for another 20 h at 323 K. The reaction mixture was mixed with as much water and chloroform so that the aqueous phase becomes lighter than the organic phase. Thereafter, the organic and aqueous phases were separated. The organic phase was dried with sodium sulfate. The solvents were distilled under reduced pressure. The remaining residue was a dark oil that was diluted with 10 ml 2-propanol and then adjusted to a pH-value of 2 by 30% aqueous nitric acid. The resulting nitric acid solution was then cooled in the refrigerator. The impure precipitated product herein was subsequently crystallized from a 1:1 mixture of ethyl acetate and ethanol. The purified product was analytically identified as an approximately pure Z-isomer of the title compound. Crystals of the title compound suitable for X-ray diffraction were obtained by slow evaporation of an ethanol solution. Details on the synthesis can be found in the literature (Ludwig & Kurt, 1985).

Refinement
H atoms were positioned geometrically with C-H = 0.93 and 0.97 Å for aromatic and methylene H atoms, respectively, and with N-H = 0.86 Å for triazole H atom, and constrained to ride on their parent atoms, with U iso (H) = 1.2 (or 1.5 for methyl groups) times U eq (C).
supplementary materials sup-2 Figures Fig. 1. The molecular structure of the title compound, with the atom numbering scheme. Displacement ellipsoids are drawn at 30% probability levels.