4-[(E)-4-Bromo­benzyl­ideneamino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione

Hoong-Kun Fun; Samuel Robinson Jebas; K V Sujith; P S Patil; B Kalluraya; A Muralidharan; S M Dharmaprakash

doi:10.1107/S1600536808021636

. 2008 Jul 16;64(Pt 8):o1509. doi: 10.1107/S1600536808021636

4-[(E)-4-Bromobenzylideneamino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione

Hoong-Kun Fun ^a,^*, Samuel Robinson Jebas ^a,^‡, K V Sujith ^b, P S Patil ^c, B Kalluraya ^b, A Muralidharan ^d, S M Dharmaprakash ^c

PMCID: PMC2962136 PMID: 21203218

Abstract

In the title molecule, C₁₀H₉BrN₄S, the dihedral angle between the triazole and benzene rings is 12.32 (19)°. An intramolecular C—H⋯S hydrogen bond generates an S(6) ring motif. In the crystal packing, centrosymmetrically related molecules are linked into a dimer by N—H⋯S hydrogen bonds, and the dimers are linked into a chain running along [1 Inline graphic 1] by Br⋯N short contacts [3.187 (3) Å]. The crystal packing is further strengthened by π–π interactions involving the triazole ring [centroid–centroid distance = 3.322 (2) Å].

Related literature

For the pharmacological activity of triazole compounds, see: Bekircan et al. (2006 ▶); Brandt et al. (2007 ▶); Holla et al. (1996 ▶, 2002 ▶); Yale et al. (1966 ▶). For bond-length data, see: Allen et al. (1987 ▶). For graph-set analysis of hydrogen bonding, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₁₀H₉BrN₄S
M _r = 297.18
Triclinic,
a = 6.9239 (5) Å
b = 7.6072 (5) Å
c = 11.5982 (8) Å
α = 82.453 (5)°
β = 88.339 (5)°
γ = 68.204 (4)°
V = 562.18 (7) Å³
Z = 2
Mo Kα radiation
μ = 3.82 mm⁻¹
T = 100.0 (1) K
0.32 × 0.31 × 0.12 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.265, T _max = 0.629
13535 measured reflections
3252 independent reflections
2538 reflections with I > 2σ(I)
R _int = 0.059

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.121
S = 1.09
3252 reflections
146 parameters
H-atom parameters constrained
Δρ_max = 1.20 e Å⁻³
Δρ_min = −1.50 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); 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, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808021636/ci2629sup1.cif

e-64-o1509-sup1.cif^{(16.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808021636/ci2629Isup2.hkl

e-64-o1509-Isup2.hkl^{(156.3KB, 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
N3—H1N3⋯S1ⁱ	0.87	2.48	3.321 (4)	164
C7—H7A⋯S1	0.93	2.50	3.223 (4)	134

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Symmetry code: (i) Inline graphic .

Acknowledgments

HKF and SRJ thank the Malaysian government and Universiti Sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. SRJ thanks the Universiti Sains Malaysia for a post-doctoral research fellowship.

supplementary crystallographic information

Comment

Various 1,2,4-triazole derivatives are found to be associated with diverse pharmacological activity (Holla et al., 1996,2002). Schiff bases of 1,2,4-triazoles find diverse applications and extensive biological activity. Schiff bases derived from 3-substituted-4-amino-5-mercapto-1,2,4 triazoles show antiinflammatory, analgesic, antimicrobial and antidepressant activities (Yale et al., 1966; Bekircan et al., 2006). The incorporation of the 1,2,4-triazole unit into Schiff-base macrocycles is of considerable current interest as complexes of 1,2,4-triazoles are being developed for potential use in applications such as magnetic materials and photochemically driven molecular devices (Brandt et al., 2007). These applications prompted us to synthesize a novel Schiff base, derived from the reaction of 4-amino-5-methyl-2,4-dihydro-3H-1,2,4- triazole-3-thione with 4-bromo benzaldehyde.

In the title compound (Fig.1), the bond lengths and angles are found to have normal values (Allen et al., 1987). The dihedral angle between the triazole ring (N2/C8/N3/N4/C9) and the benzene ring (C1-C6) is 12.32 (19)°, indicating that they are slightly twisted from each other. An intramolecular C—H···S hydrogen bond generates an S(6) ring motif (Bernstein et al., 1995).

In the crystal packing, centrosymmetrically related molecules are linked into a dimer by N—H···S hydrogen bonds (Table 1). The dimers are linked into a chain running along the [1 1 1] by Br1···N4(1+x, -1+y, 1+z) short contacts [3.187 (3) Å]. The crystal packing is further strengthened by π-π interactions between the N2/C8/N3/N4/C9 (centroid Cg1) rings of the molecules at (x, y, z) and (1-x, 1-y, z) [centroid-centroid distance = 3.322 (2) Å].

Experimental

A mixture of 4-amino-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (0.01 mol), 4-bromobenzaldehyde (0.01 mol) in ethanol (30 ml) and 2 drops of concentrated H₂SO₄ was refluxed for 3 h. The solid product obtained was collected by filtration, washed with ethanol and dried. Single crystals suitable for X-ray analysis were obtained from ethanol by slow evaporation.