3-(4-Amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)pyridinium chloride

In the title compound, C7H8N5S+·Cl−, the dihedral angle formed by the pyridine ring with the triazole ring is 10.0 (1)°. There are weak intermolecular hydrogen-bond interactions in the crystal structure, involving the NH and NH2 groups as donors, and the chloride anion, the S atom in the thioketone group and the unsubstituted ring N atom as acceptors.

In the title compound, C 7 H 8 N 5 S + ÁCl À , the dihedral angle formed by the pyridine ring with the triazole ring is 10.0 (1) . There are weak intermolecular hydrogen-bond interactions in the crystal structure, involving the NH and NH 2 groups as donors, and the chloride anion, the S atom in the thioketone group and the unsubstituted ring N atom as acceptors.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: AT2512). 3-(4-Amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)pyridinium chloride G.-Q. Zhao, Z.-F. Pan and X.-X. Tang Comment Five-and six-membered heterocyclic compounds are important constituents that often exist in biologically active natural products and synthetic compounds of medicinal interest (Gilchrist,1998). The title compound (I), is known to coordinate metal centres in a variety of coordination modes involving all combination of the S and N atoms. So it was synthesized and we report here its crystal structure.
In the crystal structure of (I) (Fig. 1), the dihedral angle formed by the pyridine ring (C1-C5/N5) and the plane of the (N2-N4/C6/C7) ring was 10.0 (1)°. The C═ S bond length of 1.666 (3)Å is in agreement with that observed before (Jian et al., 2007). In the crystal structure, there are N-H···S and N-H···N and N-H···Cl hydrogen-bond interactions to stabilize the molecular packing (table 2).

Experimental
A mixture of nicotinic acid hydrazide (0.02 mol), carbon disulfide (0.02 mol) and potassium hydroxide (0.02 mol) was stirred with ethanol (50 ml) at 293 K for 5 h, the yellow precipitate was formed, upon collection by filtration,the deposit was washed with ethanol and dried for one day in air·Then dissolved in water (100 ml), hydrazine hydrate was added at 353 K with stirring.then afford the title compound (2.4 g, yield 62%). Single crystals suitable for X-ray measurements were obtained by recrystallization from 10% HCl liquor at room temperature.

Refinement
The H atoms of the amine group and H5B bonded to C5 were found from difference Fourier map and refined freely. The other H atoms were fixed geometrically and allowed to ride on their parent atoms, with N-H and C-H distances of 0.86 and 0.93 Å, respectively, and with U iso =1.2U eq of the parent atoms. Fig. 1. The molecular structure and atom-labeling scheme for (I), with displacement ellipsoids drawn at the 30% probability level.

Figures
supplementary materials sup-2 3-(4-Amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)pyridinium chloride 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.