3-Benzyl-4-ethyl-1H-1,2,4-triazole-5(4H)-thione

Zbigniew Karczmarzyk; Monika Pitucha; Waldemar Wysocki; Anna Pachuta-Stec; Andrzej Stańczuk

doi:10.1107/S1600536812051276

. 2013 Jan 4;69(Pt 2):o155–o156. doi: 10.1107/S1600536812051276

3-Benzyl-4-ethyl-1H-1,2,4-triazole-5(4H)-thione

Zbigniew Karczmarzyk ^a,^*, Monika Pitucha ^b, Waldemar Wysocki ^a, Anna Pachuta-Stec ^b, Andrzej Stańczuk ^a

PMCID: PMC3569223 PMID: 23424446

Abstract

The title compound, C₁₁H₁₃N₃S, exists in the 5-thioxo tautomeric form. The benzene ring exhibits disorder with a refined ratio of 0.77 (2):0.23 (2) for components A and B with a common bridgehead C atom. The 1,2,4-triazole ring is essentially planar, with a maximum deviation of 0.002 (3) Å for the benzyl-substituted C atom, and forms dihedral angles of 88.94 (18) and 86.56 (49)° with the benzene rings of components A and B, respectively. The angle between the plane of the ethyl chain and the mean plane of 1,2,4-triazole ring is 88.55 (15)° and this conformation is stabilized by an intramolecular C—H⋯S contact. In the crystal, pairs of N—H⋯S hydrogen bonds link molecules into inversion dimers. π–π interactions are observed between the triazole and benzene rings, with centroid–centroid separations of 3.547 (4) and 3.544 (12) Å for components A and B, and slippages of 0.49 (6) and 0.58 (15) Å, respectively.

Related literature

For background information on 1,2,4-triazole-5-thiones, see: Saadeh et al. (2010 ▶); Akhtar et al. (2008 ▶); Al-Omar et al. (2010 ▶). For their biological activity, see: Pitucha et al. (2010 ▶). For the synthesis, see: Dobosz & Pachuta-Stec (1996 ▶). For related structures, see: Karczmarzyk et al. (2012 ▶); Kruszynski et al. (2007 ▶); Siwek et al. (2008 ▶). For graph-set motifs, see Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₁₁H₁₃N₃S
M _r = 219.30
Monoclinic,
a = 7.3731 (5) Å
b = 8.9408 (19) Å
c = 16.9936 (8) Å
β = 91.892 (4)°
V = 1119.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.26 mm⁻¹
T = 296 K
0.55 × 0.20 × 0.20 mm

Data collection

Kuma KM-4 four-circle diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.834, T _max = 0.852
3392 measured reflections
3289 independent reflections
1385 reflections with I > 2σ(I)
R _int = 0.039
2 standard reflections every 100 reflections intensity decay: 1%

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.156
S = 0.98
3289 reflections
187 parameters
6 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: KM4B8 (Gałdecki et al., 1996 ▶); cell refinement: KM4B8; data reduction: DATAPROC (Gałdecki et al., 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: SHELXL97 and WinGX (Farrugia, 2012 ▶).

Supplementary Material

Click here for additional data file.^{(23.8KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812051276/fy2077sup1.cif

e-69-0o155-sup1.cif^{(23.8KB, cif)}

Click here for additional data file.^{(158.1KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812051276/fy2077Isup2.hkl

e-69-0o155-Isup2.hkl^{(158.1KB, hkl)}

Click here for additional data file.^{(4.3KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812051276/fy2077Isup3.cml

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
C7—H7B⋯S6	0.97	2.85	3.204 (3)	103
N1—H1⋯S6ⁱ	0.86 (3)	2.46 (3)	3.303 (3)	167 (3)

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

The 1,2,4-triazole-5-thiones were found to have significant antimicrobial action (Saadeh et al., 2010; Akhtar et al., 2008; Al-Omar et al., 2010). The title compound, (I), belongs to 3- and 4-substituted derivatives of 1,2,4-triazole-5-thiones with potential antituberculosis activity against mycobacterium strains of Mycobacterium smegmatis, Mycobacterium phlei and Mycobacterium H37Ra (Pitucha et al., 2010).

The X-ray analysis of the title compound revealed that this compound exists as the 5-thioxo tautomer in the crystalline state. The molecular geometry of (I) is very similar to that observed in the related structures of ethyl 2-(3-methyl-5-sulfanylidene-4,5-dihydro-1H-1,2,4-triazol-4-yl)acetate (Karczmarzyk et al., 2012), 2-(3-methyl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-4-yl)acetic acid (Kruszynski et al., 2007) and 4-[3-(2-methyl-furan-3-yl)-5-thioxo-1,2,4-triazol-4-yl]acetic acid (Siwek et al., 2008). The 1,2,4-triazole ring is planar to within 0.002 (3) Å. The benzene ring exhibits disorder giving two components A and B with a common bridgehead C atom. The benzyl group adopts a cis-gauche conformation in respect to 1,2,4-triazole ring with the torsion angles N2—C3—C9—C10 and C3—C9—C10—C11A for benzene ring A and C3—C9—C10—C11B for benzene ring B of 25.1 (5), -102.9 (9) and -105 (4)°, respectively. The plane of the ethyl chain is positioned almost perpendicular to the mean plane of the 1,2,4-triazole ring with the dihedral angle of 88.55 (15)°. This conformation is stabilized by the C7—H71···S6 intramolecular hydrogen bond specified as S(5) in graph set notation (Bernstein et al., 1995).

In the crystal structure (Fig. 2), inversion-related molecules of (I) form molecular dimers designated as R²₂(8) rings via N1—H1···S6 intermolecular hydrogen bonds. Moreover, the π-electron systems of the pairs of triazole and benzene rings belonging to the molecules related by 2₁ axis overlap each other, with centroid-to-centroid separation of 3.547 (4) Å for ring A and 3.544 (12) Å for ring B between the triazole ring at (x, y, z) and benzene rings at (-x, y+1/2, -z+1/2) and benzene rings at (x, y, z) and triazole ring at (-x, y-1/2, -z+1/2). The angle between overlapping planes is 6.6 (3)° for A and 5.0 (10)° for B and the slippage is 0.490 (58) and 0.575 (147) Å for rings A and B, respectively.

Experimental

The title compound, (I), was prepared by the cyclization reaction of 1-benzyl-4-ethylthiosemicarbazide in alkaline medium according to the metod described by Dobosz & Pachuta-Stec (1996). Crystals uitable for X-ray diffraction analysis were grown by slow evaporation of ethanol solution.