1-(3-Bromo­prop­yl)-4-(2-pyrid­yl)-1H-1,2,3-triazole

James D Crowley; Pauline H Bandeen; Lyall R Hanton

doi:10.1107/S1600536809012148

. 2009 Apr 8;65(Pt 5):o999–o1000. doi: 10.1107/S1600536809012148

1-(3-Bromopropyl)-4-(2-pyridyl)-1H-1,2,3-triazole

James D Crowley ^a,^*, Pauline H Bandeen ^a, Lyall R Hanton ^a

PMCID: PMC2977690 PMID: 21584033

Abstract

In the structure of the title compound, C₁₀H₁₁BrN₄, the plane of the substituted 1,2,3-triazole ring is tilted by 14.84 (10)° with respect to the mean plane of the pyridine ring. The pyridine and closest triazole N atoms adopt an anti arrangement which removes any lone pair–lone pair repulsions between the N atoms. This conformation is further stabilized by weak intermolecular C—H⋯N interactions. There are two molecules in the unit cell, which form a centrosymmetric head-to-tail dimer. The dimers are stabilized through π–π interactions [centroid–centroid distance = 3.733 (4) Å and mean interplanar distance = 3.806 (12) Å] between the substituted 1,2,3-triazole ring and the pyridine rings in adjacent molecules. Each dimer interacts with two neighbouring dimers above and below, forming a slipped stack of dimers through the crystal. The 3-bromopropyl chain sits over the pyridine ring of a neighbouring molecule and the triazole rings of nearby molecules are adjacent.

Related literature

For details of the Cu(I)-catalysed 1,3-cycloaddition of organic azides with terminal alkynes, see: Rostovtsev et al. (2002 ▶); Tornoe et al. (2002 ▶); Meldal & Tornoe (2008 ▶). For applications of pyridyl-functionalized 1,2,3-triazoles, see: Li & Flood (2008 ▶); Meudtner & Hecht (2008 ▶); Krivopalov & Shkurko (2005 ▶); Li et al. (2007 ▶); Richardson et al. (2008 ▶). For related structures, see Schweinfurth et al. (2008 ▶); Obata et al. (2008 ▶).

Experimental

Crystal data

C₁₀H₁₁BrN₄
M _r = 267.14
Triclinic,
a = 5.658 (2) Å
b = 9.688 (4) Å
c = 10.191 (4) Å
α = 84.498 (3)°
β = 85.663 (2)°
γ = 83.854 (2)°
V = 551.6 (4) Å³
Z = 2
Mo Kα radiation
μ = 3.70 mm⁻¹
T = 90 K
0.53 × 0.23 × 0.11 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.358, T _max = 0.66
8776 measured reflections
1879 independent reflections
1759 reflections with I > 2σ(I)
R _int = 0.043

Refinement

R[F ² > 2σ(F ²)] = 0.027
wR(F ²) = 0.071
S = 0.97
1879 reflections
136 parameters
H-atom parameters constrained
Δρ_max = 0.64 e Å⁻³
Δρ_min = −0.61 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2 and SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Bruno et al., 2002 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶) and enCIFer (Allen et al., 2004 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809012148/fj2204sup1.cif

e-65-0o999-sup1.cif^{(14.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809012148/fj2204Isup2.hkl

e-65-0o999-Isup2.hkl^{(90.6KB, 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
C7—H7⋯N2ⁱ	0.93	2.62	3.449 (4)	149
C10—H10B⋯N1ⁱⁱ	0.97	2.51	3.450 (4)	164

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

Acknowledgments

We thank the Chemistry Department, University of Otago, for financial assistance.

supplementary crystallographic information

Comment

The Cu(I)-catalyzed 1,3-cycloaddition of organic azides with terminal alkynes (the CuAAC reaction) (Rostovtsev et al. 2002; Tornoe et al. 2002) has quickly become an indispensable tool for functional molecule synthesis and renewed interest in the chemistry of functionalized 1,2,3-triazoles (Meldal & Tornoe, 2008). Because they are readily synthesized using the CuAAC reaction, pyridyl functionalized 1,2,3-triazoles have begun attracting significant attention in a range of areas including anion recognition (Li & Flood, 2008), stimuli responsive foldamers (Meudtner & Hecht, 2008), drug discovery (Krivopalov & Shkurko, 2005) and coordination chemistry (Li et al. 2007; Richardson et al., 2008; Schweinfurth et al., 2008; Obata et al., 2008)

The molecular structure of the new triazole compound 1 is shown in Fig. 1. The molecule consists of an essentially co-planar (2-pyridyl) and 1,2,3-triazole units attached to a 3-bromopropyl chain, the plane of the substituted 1,2,3-triazole ring is tilted by 14.84 (10)° with respect to the mean plane of the pyridine ring system. As is commonly observed (Obata et al., 2008; Schweinfurth et al., 2008) N1 in the pyridine ring and N2 of the triazole ring adopt an anti arrangement which removes any lone pair-lone pair repulsions between the nitrogen atoms. Additionally, the anti conformation is stabilized by weak C—H···N interactions. There are two molecules of 1 in the unit cell which form a centrosymmetric head to tail dimer that is stabilized through a π-π interaction [centroid-centroid distance = 3.733 (4) Å, mean interplanar distance 3.806 (12) Å] between the substituted 1,2,3-triazole and the pyridine rings in adjacent molecules. In the extended crystal each dimer interacts with two neighbouring dimers above and below to form slipped stacks of dimers through the crystal. The 3-bromopropyl chain sits over the pyridine ring of the neighbouring molecule and the triazole rings of nearby molecules are adjacent [centroid-centroid distance = 4.691 (4) Å]. Unlike the dimer units, the extended stacks appear not to be stabilized by π-π interactions, the mean interplanar distance between dimers of 1 is 4.060 Å are outside the range normally expected for a π-π interaction. A steric interaction between the bromopropyl chain on one molecule of 1 and the pyridine ring on the adjacent molecule in the next dimer prevents a closer face to face interaction of the aromatic rings in the different dimer units.

Experimental

The title compound, C₁₀H₁₁BrN₄ (1) was obtained as a by-product during the attempted synthesis of a ditopic propyl bridged bis((2-pyridyl)-1,2,3-triazole) ligand. X-ray quality colourless crystals were obtained by slow evaporation of a petroleum ether solution of 1 but were weakly diffracting.

To a stirred solution of 1,3-dibromopropane (0.301 g, 1.5 mmol, 1.00 eq.) in DMF/H₂O (15 ml, 4:1) was added NaN₃ (0.205 g, 3.1 mmol, 2.05 eq.), Na₂CO₃ (0.13 g, 1.2 mmol, 0.8 eq.), CuSO₄.5H₂O (0.150 g, 0.6 mmol, 0.40 eq.), ascorbic acid (0.210 g, 1.2 mmol, 0.80 eq). 2-Ethynylpyridine (0.323 g, 3.1 mmol, 2.05 eq.) was added and the reaction mixture was stirred at room temperature for 20 h. The resulting suspension was then partitioned between aqueous NH₄OH/edta (1 M, 100 ml) and CH₂Cl₂ (50 ml) and the layers separated. The organic phase was washed with H₂O (100 ml) and brine (100 ml), dried (MgSO₄) and the solvent removed under reduced pressure. Chromatography (gradient CH₂Cl₂/acetone to a ratio 9:1) gave the product as a white solid. Yield: 0.190 g, 47%. Mp 89–91 °C; ¹H NMR (300 MHz, CDCl₃) δ 8.58 (ddd, J = 0.9, J = 1.7, J = 4.9, 1H, H₁), 8.23–8.12 (m, 2H, H_4,5), 7.78 (td, J = 1.8, J = 7.8, 1H, H₃), 7.26–7.21 (m, 1H, H₂), 4.62 (t, J = 6.5, 2H, H₁₀), 3.40 (t, J = 6.2, 2H, H₈), 2.52 (p, J = 6.4, 2H, H₉); ¹³C NMR (75 MHz, CDCl₃) δ: 150.2, 149.5, 148.5, 136.9, 122.9, 122.6, 120.3, 48.3, 32.7, 29.3; I.R. (KBr): ν(cm^-1) 3400–3200 (br), 3116, 3087, 2924, 1701, 1617, 1607, 1598, 1572, 1548, 1473, 1466, 1447, 1421, 1358, 1317, 1287, 1250, 1224, 1204, 1144, 1080, 1048, 983, 969, 891, 855, 844, 826, 786, 744, 708; HRESI-MS (MeOH): m/z = 289.0066 [M+Na]+ (calc. for C₁₀H₁₁⁷⁹BrN₄Na 289.0065 [M+Na]+), 291.0040 [M+Na]+ (calc. for C₁₀H₁₁⁸¹BrN₄Na 291.0044 [M+Na]+; Anal. calcd for C₁₀H₁₁BrN₄(H₂O): C, 44.96; H, 4.15; N, 20.97; Found: C, 45.36; H, 4.24; N, 21.03.