4-(1,2,4-Triazol-1-yl)aniline

Hoong-Kun Fun; Ching Kheng Quah; B Chandrakantha; Arun M Isloor; Prakash Shetty

doi:10.1107/S1600536810052025

. 2010 Dec 18;67(Pt 1):o164. doi: 10.1107/S1600536810052025

4-(1,2,4-Triazol-1-yl)aniline

Hoong-Kun Fun ^a,^*,^‡, Ching Kheng Quah ^a,^§, B Chandrakantha ^b, Arun M Isloor ^c, Prakash Shetty ^d

PMCID: PMC3050328 PMID: 21522671

Abstract

In the title compound, C₈H₈N₄, the dihedral angle between the triazole ring [maximum deviation = 0.003 (1) Å] and the benzene ring is 34.57 (7)°. In the crystal, molecules are linked into sheets lying parallel to the ac plane via intermolecular N—H⋯N and C—H⋯N hydrogen bonds. Aromatic π–π [centroid–centroid distance = 3.6750 (8) Å] stacking and N—H⋯π interactions are also observed.

Related literature

For general background to and the biological activity of triazole derivatives, see: Isloor et al. (2000 ▶, 2009 ▶); Soliman et al. (2001 ▶); Holla et al. (2000 ▶); Sunil et al. (2009 ▶). For bond-length data, see: Allen et al. (1987 ▶). For a related structure, see: Fun et al. (2010 ▶).

Experimental

Crystal data

C₈H₈N₄
M _r = 160.18
Monoclinic,
a = 5.5488 (1) Å
b = 7.3656 (2) Å
c = 19.5477 (5) Å
β = 99.416 (2)°
V = 788.15 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.50 × 0.42 × 0.14 mm

Data collection

Bruker SMART APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.957, T _max = 0.988
8036 measured reflections
2160 independent reflections
1722 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.118
S = 1.05
2160 reflections
110 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.17 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/S1600536810052025/hb5764sup1.cif

e-67-0o164-sup1.cif^{(15.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810052025/hb5764Isup2.hkl

e-67-0o164-Isup2.hkl^{(106.2KB, hkl)}

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

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

Cg2 is the centroid of the C3–C8 phenyl ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H2N4⋯N1ⁱ	0.871 (16)	2.208 (16)	3.0709 (18)	171.1 (15)
C1—H1A⋯N2ⁱⁱ	0.93	2.50	3.4035 (16)	166
N4—H1N4⋯Cg2ⁱⁱⁱ	0.87 (2)	2.58 (2)	3.3929 (16)	156.0 (17)

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

Acknowledgments

HKF and CKQ thank Universiti Sains Malaysia (USM) for the Research University Grant (No. 1001/PFIZIK/811160). CKQ also thanks USM for the award of a USM fellowship. AMI is thankful to the Director of the National Institute of Technology for providing research facilities and also thanks the Board for Research in Nuclear Sciences, Department of Atomic Energy, Government of India, for a Young Scientist Award.

supplementary crystallographic information

Comment

Compounds incorporating heterocyclic ring systems continue to attract considerable interests due to the wide range of biological activities they possess (Isloor et al., 2000). Triazoles are a class of heterocyclic compounds having a five-membered ring of two carbon atoms and three nitrogen atoms (Soliman et al., 2001). They have wide range of applications. In last few decades, triazoles have received much significant attention in the field of medicinal chemistry because of their diversified biological properties like antibacterial (Isloor et al., 2009) and antifungal (Holla et al., 2000) activities. In recent years, 1,2,4-triazole derivatives have been found to associate with anticancer properties (Sunil et al., 2009). It is also observed that incorporation of aryl constituent into the triazoles ring systems augments the biological activities considerably.

In the title molecule (Fig. 1), the triazol-1-yl ring (N1-N3/C1/C2, maximum deviation = 0.003 (1) Å at atom N3) is inclined at angle of 34.57 (7)° with phenyl (C3-C8) ring. Bond lengths (Allen et al., 1987) and angles are within normal ranges and are comparable to a related structure (Fun et al., 2010).

In the crystal packing (Fig. 2), the molecules are linked into two-dimensional sheets parallel to the ac-plane via intermolecular N4–H2N4···N1 and C1–H1A···N2 hydrogen bonds. π-π stacking interactions between the centroids of N1-N3/C1/C2 triazol-1-yl rings (Cg1), with Cg1···Cg1ⁱ distance of 3.6750 (8) Å [symmetry code: (i) 1-X, -Y, 2-Z] are observed. The crystal structure is further consilidated by N4–H1N4···Cg2 (Table 1) interactions, where Cg2 is the centroid of C3-C8 phenyl ring.

Experimental

1,2,4-Triazole (2 g, 0.02 mol) was added lot-wise to a suspension of sodium hydride (60%, 1.47 g, 0.0308 mol) in dry DMF (20 ml) at 0°C. After the addition, the reaction mixture was stirred at the same temperature for 30 min. A solution of 4-fluoro nitrobenzene (2.82 g, 0.02 mol) in dry DMF (20 ml) was then added and the reaction mixture was stirred at room temperature for 18 h. The reaction mixture was then quenched with ice water and extracted with ethyl acetate. The organic layer was concentrated to afford a yellow solid as a nitro compound intermediate (3 g). This nitro compound was taken in methanol (30 ml) and hydrogenated using 10% palladium on carbon (0.2 g) at 3-kg pressure of hydrogen. After the reaction was over, the catalyst was filtered, the filtrate was concentrated to afford the title compound as a yellow solid. Yellow blocks were recrystallised from ethanol. Yield : 2.8g, 60 %. M.p. 433-435K.