3-Methyl-4-[(E)-3-thien­ylmethyl­idene­amino]-1H-1,2,4-triazole-5(4H)-thione

Mohammad Asad; Chuan-Wei Oo; Hasnah Osman; Chin Sing Yeap; Hoong-Kun Fun

doi:10.1107/S1600536810041152

. 2010 Oct 20;66(Pt 11):o2861–o2862. doi: 10.1107/S1600536810041152

3-Methyl-4-[(E)-3-thienylmethylideneamino]-1H-1,2,4-triazole-5(4H)-thione

Mohammad Asad ^a, Chuan-Wei Oo ^a,^‡, Hasnah Osman ^a, Chin Sing Yeap ^b,^§, Hoong-Kun Fun ^b,^*,^¶

PMCID: PMC3009062 PMID: 21589044

Abstract

The asymmetric unit of the title compound, C₈H₈N₄S₂, contains two crystallographically independent molecules. The thiophene ring of one molecule is disordered over two positions with refined site occupancies of 0.6375 (19) and 0.3625 (19). One molecule is almost planar and the other one is twisted, the dihedral angles between the thiophene and triazole rings being 7.28 (7) and 48.9 (2)° [48.5 (4)° for the minor component], respectively. An intramolecular C—H⋯S hydrogen bond stabilizes the molecular conformation of the planar molecule. In the crystal, the two molecules are interconnected by N—H⋯S hydrogen bonds into dimers, which are further consolidated into chains along the b axis by C—H⋯N hydrogen bonds. Weak C–H⋯π and π–π interactions [centroid–centroid distance = 3.5149 (7) Å] are also observed.

Related literature

For general background and the biological activity of Schiff bases of 1,2,4-triazole derivatives, see: Ghazzali et al. (2010 ▶); Xia et al. (2010 ▶); Aytac et al. (2009 ▶); Siddiqui et al. (2006 ▶); Kucukguzel et al. (2008 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₈H₈N₄S₂
M _r = 224.30
Triclinic,
a = 9.3108 (7) Å
b = 10.2848 (8) Å
c = 12.7798 (10) Å
α = 66.632 (2)°
β = 83.409 (2)°
γ = 63.974 (2)°
V = 1006.88 (13) Å³
Z = 4
Mo Kα radiation
μ = 0.49 mm⁻¹
T = 100 K
0.36 × 0.25 × 0.23 mm

Data collection

Bruker APEXII DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.845, T _max = 0.896
23519 measured reflections
8745 independent reflections
7500 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.114
S = 1.06
8745 reflections
288 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 1.06 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810041152/rz2500sup1.cif

e-66-o2861-sup1.cif^{(23.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810041152/rz2500Isup2.hkl

e-66-o2861-Isup2.hkl^{(427.7KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3A—H3NA⋯S2Bⁱ	0.894 (19)	2.46 (2)	3.3494 (11)	177.7 (18)
N3B—H3NB⋯S2Aⁱⁱ	0.84 (2)	2.45 (2)	3.2728 (12)	167.7 (19)
C5A—H5AA⋯S2A	0.93	2.50	3.2311 (12)	135
C8B—H8BA⋯N4Aⁱⁱⁱ	0.96	2.59	3.5503 (16)	175
C5B—H5BA⋯Cg1^iv	0.93	2.91	3.4955 (12)	122

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

The authors are thankful to Universiti Sains Malaysia (USM) for providing the necessary research facilities and RU research funding under grant No. 1001/PKIMIA/811134. MA also thanks Universiti Sains Malaysia for the award of a post doctoral fellowship and HKF and CSY thank USM for the Research University Grant No. 1001/PFIZIK/811160.

supplementary crystallographic information

Comment

Schiff bases of 1,2,4-triazole and its derivatives have been the subject of current research in the field of pharmacology and coordination chemistry (Ghazzali et al., 2010). Due to the bioactivity associated with substituted 1,2,4-triazoles, researchers and chemists are very much interested to study the chemistry of these compounds, as they exhibit a broad spectrum of biological properties such as anticancer (Xia et al., 2010), anti-inflammatory/analgesic (Aytac et al., 2009), antibacterial/antifungal (Siddiqui et al., 2006), antiviral/anti-HIV and anti-tuberculosis (Kucukguzel et al., 2008) activities.

The asymmetric unit of the title compound consists of two crystallographically independent molecules (Fig. 1). The thiophene ring of molecule B is disordered over two positions with refined site occupancies of 0.6375 (19) and 0.3625 (19). Both molecules exist in an E configuration with respect to the central C=N double bond. Molecule A is almost planar and molecule B is twisted, the dihedral angles between the thiophene ring and the triazole ring being 7.28 (7)° and 48.9 (2)° [48.5 (4)° for the minor component] respectively. Intramolecular C—H···S hydrogen bonds stabilize the molecular structures. In the crystal structure, the two molecules are interconnected by N3A—H3NA···S2B and N3B—H3NB···S2A hydrogen bonds (Table 1) into dimers and these dimers are further consolidated into chains along the b axis (Fig. 2) by C8B—H8BA···N4A hydrogen bonds (Table 1). Weak C–H···π and π···π interactions are also observed [Cg1···Cg2^v = 3.5149 (7) Å; (v) 1 - x, -y, -z. Cg1 and Cg2 are centroids of S1A–C1A–C4A–C3A–C2A and N2A–C6A–N3A–N4A–C7A ring, respectively].

Experimental

A mixture of 3-methyl-4-amino-5-mercapto-1,2,4-triazole (4.46 mmol, 0.58 g) and thiophene-3-carboxaldehyde (4.46 mmol, 0.5 g) containing pyridine (0.1 ml) in ethanol was refluxed for about 13 to 14 h. The reaction mixture was cooled to room temperature and the light yellow solid was filtered off, washed with water, dried and recrystallized from chloroform-methanol (1:1 v/v) to get the title compound in 65% yield.