1-[2-(2,4-Dichlorophenyl)pentyl]-1H-1,2,4-triazole

The title compound, C13H15Cl2N3, also known as penconazole, crystallizes as a racemate. The dihedral angle between the benzene and triazole rings is 24.96 (13)°. In the crystal structure, molecules are linked into chains running parallel to the c axis by intermolecular C—H⋯N hydrogen-bonding interactions.

The title compound, C 13 H 15 Cl 2 N 3 , also known as penconazole, crystallizes as a racemate. The dihedral angle between the benzene and triazole rings is 24.96 (13) . In the crystal structure, molecules are linked into chains running parallel to the c axis by intermolecular C-HÁ Á ÁN hydrogen-bonding interactions.

Experimental
Financial support from the Universitá Politecnica delle Marche and the Universitá degli Studi di Parma is gratefully acknowledged.
I and the evaluation of the percentage of the by-product II.

Experimental
The title compound was prepared according to the literature reports (Tao et al., 2003). This method afforded compounds I and II in a 93:3 ratio. The two compounds were separated by chromatography on SiO 2 column eluting with cyclohexane/ ethyl acetate (9:1 v/v). Crystals of the title compound suitable for X-ray analysis were obtained on slow evaporation of an no molecular ion peak was observed; the highest peaks are those corresponding to the loss of a chlorine atom. The 1 H-NMR spectrum of compound II shows a singlet at δ = 7.89 corresponding to the two equivalent H atoms of the 1,3,4-triazol-1-yl ring, the other part of the spectrum is strictly similar to that of compound I. Melting points were determined by an electrochemical apparatus and were uncorrected. 1 H-NMR spectra were recorded on a Varian Gemini 200 MHz. IR spectra were recorded in the solid state with a Perkin-Elmer MGX1 spectrophotometer equipped with Spectra Tech. Mass spectra were recorded with a Carlo Erba QMD 1000 mass spectrometer in positive EI mode.
supplementary materials sup-2 Refinement All H atoms were positioned geometrically with C-H = 0.93-0.98 Å, and refined using a riding model approximation with U iso (H) = 1.2 U eq (C) or 1.5 U eq (C) for methyl H atoms. Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level.