6-(3-Pyrid­yl)-3-(3,4,5-trimethoxy­phen­yl)-1,2,4-triazolo[3,4-b][1,3,4]thia­diazole

Haitang Du; Haijun Du; Ying An; Shengnan Li

doi:10.1107/S1600536808019855

. 2008 Jul 5;64(Pt 8):o1402. doi: 10.1107/S1600536808019855

6-(3-Pyridyl)-3-(3,4,5-trimethoxyphenyl)-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole

Haitang Du ^a,^*, Haijun Du ^b, Ying An ^c, Shengnan Li ^c

PMCID: PMC2962035 PMID: 21203122

Abstract

In the molecule of the title compound, C₁₇H₁₅N₅O₃S, the planar central heterocylic ring system is oriented with respect to the benzene and pyridine rings at dihedral angles of 6.61 (3) and 19.22 (3)°, respectively. An intramolecular C—H⋯N hydrogen bond results in the formation of a six-membered ring, adopting a flattened boat conformation. In the crystal structure, intermolecular C—H⋯N hydrogen bonds link the molecules.

Related literature

For general background, see: Karabasanagouda et al. (2007 ▶); Mathew et al. (2007 ▶). For ring conformation puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₇H₁₅N₅O₃S
M _r = 369.40
Monoclinic,
a = 7.4682 (15) Å
b = 14.128 (3) Å
c = 15.550 (3) Å
β = 90.46 (3)°
V = 1640.6 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 113 (2) K
0.20 × 0.06 × 0.04 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005 ▶) T _min = 0.956, T _max = 0.991
18716 measured reflections
3620 independent reflections
3121 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.108
S = 1.17
3620 reflections
238 parameters
H-atom parameters constrained
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.41 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku/MSC, 2005 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808019855/hk2481sup1.cif

e-64-o1402-sup1.cif^{(20.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808019855/hk2481Isup2.hkl

e-64-o1402-Isup2.hkl^{(177.5KB, 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
C2—H2⋯N4	0.95	2.40	3.0869 (19)	129
C9—H9A⋯N1ⁱ	0.98	2.60	3.576 (2)	171
C8—H8C⋯N5ⁱⁱ	0.98	2.63	3.573 (2)	161
C14—H14⋯N2ⁱⁱⁱ	0.95	2.57	3.410 (2)	148

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

Acknowledgments

The authors thank Guiyang College (grant No. 2008012) for financial support.

supplementary crystallographic information

Comment

1,2,4-Triazole and 1,3,4-thiadiazole represent one of the most biologically active classes of compounds, possessing a wide spectrum of activities. Various substituted 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles are associated with diverse pharmacological activities such as antimicrobial (Karabasanagouda et al., 2007) and anti-inflammatory activity (Mathew et al., 2007). We report herein the crystal structure of the title compound.

In the molecule of the title compound (Fig. 1) the bond lengths and angles are within normal ranges. Rings A (C1–C6), B (N1–N3/C10/C11), C (S1/N3/N4/C11/C12) and D (N5/C13–C17) are, of course, planar, and the dihedral angles between them are A/B = 6.28 (3)°, A/C = 6.97 (3)°, A/D = 25.30 (3)°, B/C = 0.95 (2)°, B/D = 19.38 (3)° and C/D = 19.06 (3)°. So, rings B and C are nearly coplanar. The coplanar ring system is oriented with respect to rings A and D at dihedral angles of 6.61 (3)° and 19.22 (3)°. The intramolecular C—H···N hydrogen bond (Table 1) results in the formation of a six-membered ring E (N3/N4/C1/C2/C10/H2), in which it adopts flattened-boat [φ = -95.41 (2)° and θ = 21.96 (3)°] conformation, having total puckering amplitude, Q_T, of 1.463 (3) Å (Cremer & Pople, 1975).

In the crystal structure, intermolecular C—H···N hydrogen bonds (Table 1) link the molecules, in which they may be effective in the stabilization of the structure.

Experimental

For the preparation of the title compound, 4-amino-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazole-3-thiol (0.01 M) and nicotinic acid (0.01 M) were dissolved in dry phosphorous oxychloride (10 ml). The resulted solution was further heated under reflux for 7 h. The reaction mixture was cooled to room temperature and the mixture was gradually poured onto crushed ice with stirring. Finally, powdered potassium carbonate and the required amount of solid potassium hydroxide were added until the pH of the mixture was raised to 8, to remove the excess of phosphorous oxychloride. The mixture was allowed to stand overnight and the solid was separated. It was filtered, washed with cold water, and then dried. Crystals suitable for X-ray analysis were obtained by the recrystallization of the solid residue from a mixture of N,N-dimethylformamide/ethanol (1:1) by slow evaporation at room temperature.