2,5-Bis(5-methyl­pyrazin-2-yl)-1,3,4-oxadiazole

Yue Ju; Jing-Min Wu; Cheng-Peng Li; Jian-Hua Guo

doi:10.1107/S1600536811015029

. 2011 May 14;67(Pt 6):o1416. doi: 10.1107/S1600536811015029

2,5-Bis(5-methylpyrazin-2-yl)-1,3,4-oxadiazole

Yue Ju ^a, Jing-Min Wu ^a, Cheng-Peng Li ^a,^*, Jian-Hua Guo ^a

PMCID: PMC3120570 PMID: 21754798

Abstract

In the title molecule, C₁₂H₁₀N₆O, the dihedral angle between the two pyrazine rings [planar to within 0.009 (3) and 0.018 (3) Å] is 5.62 (15)°. They deviate from the central oxadiazole ring [planar to within 0.005 (3) Å] by 1.52 (16) and 5.55 (17)°, respectively. In the crystal, C—H⋯N interactions involving the pyrazine rings connect molecules to form zigzag supramolecular chains propagating in [010].

Related literature

For background information and applications of oxadiazole derivatives, see: Schnurch et al. (2006 ▶); Crabtree (2005 ▶); Venkatakrishnan et al. (2000 ▶). For related oxadiazole derivatives, see: Du et al. (2005 ▶, 2006 ▶, 2009 ▶).

Experimental

Crystal data

C₁₂H₁₀N₆O
M _r = 254.26
Monoclinic,
a = 3.9084 (8) Å
b = 19.054 (4) Å
c = 16.328 (4) Å
β = 101.64 (3)°
V = 1191.0 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 296 K
0.16 × 0.12 × 0.08 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.984, T _max = 0.992
6101 measured reflections
2108 independent reflections
1077 reflections with I > 2σ(I)
R _int = 0.074

Refinement

R[F ² > 2σ(F ²)] = 0.064
wR(F ²) = 0.120
S = 1.00
2108 reflections
174 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 1999 ▶); software used to prepare material for publication: SHELXTL (Bruker, 2007 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811015029/su2270sup1.cif

e-67-o1416-sup1.cif^{(17.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811015029/su2270Isup2.hkl

e-67-o1416-Isup2.hkl^{(103.7KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811015029/su2270Isup3.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
C11—H11⋯N2ⁱ	0.93	2.59	3.414 (4)	148

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was supported financially by Tianjin Normal University (grant No. 52X09004). Professor Hai-Bin Song, Department of Chemistry, Nankai University, Tianjin 300371, People’s Republic of China, is thanked for the data collection.

supplementary crystallographic information

Comment

Currently derivatives of oxadiazole systems are of growing research interest, as they are precursors to functional N-heterocyclic compounds, as well as being used in pharmaceuticals as metabolically stable surrogates and photographically active systems (Schnurch et al., 2006; Crabtree, 2005; Venkatakrishnan, et al., 2000). Among them, oxadiazole compounds decorated by different groups on the 5-membered ring, such as pyridyl (Du, et al., 2009) and pyrazinyl rings, (Du, et al., 2005, 2006), also show interesting coordination behaviors. However, the related ligands involving methyl-pyrazinyl groups remain uninvestigated. They may display three typical configurations under different surroundings and multiple binding patterns (hexadentate at the most) during coordination. In this contribution, we present the crystal structure of the title compound, a bis(4-methylpyrazinyl) substituted oxadiazole. It was prepared by the reaction of 5-methylpyrazine-2-carboxylic acid and hydrazine dihydrochloride in the presence of polyphosphoric acid and anhydrous phosphorus pentoxide.

In the molecule of the title compound, Fig.1, pyrazinyl ring A [(N1,C3,C2,N2,C13,C4); planar to within 0.009 (3) Å] is inclined to pyrazinyl ring B [(N5,C9,C10,N6,C11,C9); planar to within 0.018 (3) Å] by 5.62 (15) °. They deviate from the central oxadiazole ring (planar to within 0.005 (3) Å) by 1.52 (16)° and 5.55 (17)°, respectively.

In the crystal a C—H···N interaction, involving pyrazinyl rings A and B, connect molecules to form zigzag poylmer chains propagating in [010] (Table 1 and Fig. 2).

Experimental

5-Methylpyrazine-2-carboxylic acid (0.3 mol) and hydrazine dihydrochloride (0.2 mol) were mixed with stirring, to which polyphosphoric acid (85%, 60 ml) was added. Then, anhydrous phosphorus pentoxide (0.6 mol) was carefully added to the above mixture. The viscous solution was heated at 393 K, with stirring for ca 6 h. After cooling to room temperature, the resultant viscous liquid was poured over distilled water with stirring, dissolved, and then neutralized with sodium hydrate (3 mol/L). A large amount of orange precipitation of title compound was obtained and dried in air. Its single-crystal can be recrystallized from its methanol solution (Yield: 63%). Anal. Calc. for C₁₂H₁₀N₆O: C, 55.69; H, 3.96; N, 33.05%. Found: C, 55.62; H, 4.01; N, 33.09%. Spectroscopic data for the title compound is given in the archived CIF.