N-(2-Hydroxy­ethyl)-2-[3-(p-tol­yl)triazen-1-yl]benzamide

Fernando Rocha-Alonzo; Gerardo Aguirre; Miguel Parra-Hake

doi:10.1107/S1600536809011908

. 2009 Apr 8;65(Pt 5):o990–o991. doi: 10.1107/S1600536809011908

N-(2-Hydroxyethyl)-2-[3-(p-tolyl)triazen-1-yl]benzamide

Fernando Rocha-Alonzo ^a, Gerardo Aguirre ^a,^*, Miguel Parra-Hake ^a

PMCID: PMC2977684 PMID: 21584027

Abstract

In the solid state, the structure of the title compound, C₁₆H₁₈N₄O₂, is stabilized by intermolecular N—H⋯O and O—H⋯O hydrogen bonds. These hydrogen bonds arrange the molecules into a double-layer supramolecular structure. The molecular conformation is is consolidated by an intramolecular N—H⋯N hydrogen bond. The dihedral angle between the aromatic rings is 8.01 (10)°

Related literature

For the synthesis of new ligands to stabilize dinuclear complexes and control their reactivity, see: Das et al. (2008 ▶); Estevan et al. (2006 ▶); Jie et al. (2007 ▶); Müller & Vogt (2007 ▶); Schilling et al. (2008 ▶). For the synthesis of 1,3-bis(aryl)triazenes as precursors for triazenido ligands bearing Lewis basic ortho substituents such as ester, methoxy and methylmercapto groups, see: Nuricumbo-Escobar et al.(2007 ▶); Ríos-Moreno et al. (2003 ▶); Rodríguez et al. (1999 ▶); Tejel et al. (2004 ▶). The starting material 2-[4,5-dihydro-1,3-oxazol-2-yl]aniline was synthesized by a modification of the literature method of Gómez et al. (2005 ▶). For bond-length data, see: Allen et al. (1987 ▶); Orpen et al. (1989 ▶).

Experimental

Crystal data

C₁₆H₁₈N₄O₂
M _r = 298.34
Monoclinic,
a = 16.846 (2) Å
b = 12.2053 (17) Å
c = 7.4302 (11) Å
β = 93.212 (13)°
V = 1525.3 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 K
0.40 × 0.22 × 0.14 mm

Data collection

Bruker P4 diffractometer
Absorption correction: none
4153 measured reflections
3067 independent reflections
1778 reflections with I > 2σ(I)
R _int = 0.044
3 standard reflections every 97 reflections intensity decay: 2.8%

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.188
S = 1.04
3067 reflections
201 parameters
H-atom parameters constrained
Δρ_max = 0.57 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: XSCANS (Siemens, 1996 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809011908/kp2210sup1.cif

e-65-0o990-sup1.cif^{(17.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809011908/kp2210Isup2.hkl

e-65-0o990-Isup2.hkl^{(150.5KB, 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
N4—H4A⋯N1	0.86	2.05	2.696 (3)	132
O2—H2B⋯O1ⁱ	0.82	1.92	2.729 (2)	169
N3—H3A⋯O2ⁱⁱ	0.86	2.00	2.851 (2)	170

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

Acknowledgments

We gratefully acknowledge support for this project by Consejo Nacional de Ciencia y Tecnología (CONACyT grant 60467), Consejo del Sistema Nacional de EducaciónTecnológica (COSNET grant 486–02-P) and a graduate scholarship from CONACyT for F. Rocha-Alonzo. The authors are indebted to Adrián Ochoa Terán and Ignacio Rivero Espejel for their support in this work. We acknowledge Universidad Autónoma de Nuevo-León (Monterrey, México) for diffractometer time.

supplementary crystallographic information

Comment

The synthesis of alternative ligands to stabilize dinuclear complexes and control their reactivity is an area of great importance in coordination and organometallic chemistry (for recent literature see: Das et al., 2008; Estevan et al., 2006; Jie et al., 2007; Müller & Vogt, 2007; Schilling et al., 2008). In this context, we have focused our attention to the synthesis of 1,3-bis(aryl)triazenes as precursors for triazenido ligands bearing Lewis basic ortho substituents such as ester, methoxy and methylmercapto groups (Nuricumbo-Escobar et al., 2007; Ríos-Moreno et al., 2003; Rodríguez et al., 1999; Tejel et al., 2004); it has been found that the nature of the substituent produces a dramatic impact on their coordination chemistry and reactivity. As part of our ongoing research, we have synthesized the title compound (I, Fig. 1) using the diazonium salt N-coupling methodology.

The molecular structure of (I) shows the characteristic trans stereochemistry about N═N of the diazoamino group of free triazenes. The N1═N2 bond [1.264 (3) Å] is longer than the typical value for N═N bond (1.222 Å), whereas the N2—N3 bond [1.320 (3) Å] is shorter than typical value for a Nsp³—Nsp² single bond (1.420 Å) (Allen et al., 1987). In addition, the C7—N3 bond [1.395 (3) Å] is shorter than the characteristic C_aryl—NH single bonds for secondary aromatic amines (1.419 Å) (Orpen, et al., 1989). An intramolecular N1—H···N4 hydrogen bond is observed (Fig. 1 and Table 1).

In the crystal structure, adjacent units are arranged into a two-dimensional network along the (100) plane via intermolecular N— H···O and O—H···O hydrogen bond interactions (Fig. 2 and Table 1). These layers are linked together via intermolecular N—H···O and O—H···O hydrogen bonds forming a zig-zag bilayered array along the [001] direction (Fig. 3).

Experimental

The synthesis of the title compound included reagents and solvents of reagent grade, which were used without further purification. As a starting material we synthesized 2-[4,5-dihydro-1,3-oxazol-2-yl]aniline by a modification of the Gómez and coworkers methodology (Gómez et al., 2005). 2-[4,5-Dihydro-1,3-oxazol-2-yl]aniline (1.00 g, 6.17 mmol) was dissolved in aqueous HCl 2 M (9.25 ml, 18.50 mmol) and cooled to 268 K. A sodium nitrite solution (0.51 g, 7.40 mmol) in water (6 ml) was slowly added with continuous stirring. A solution of p-toluidine (0.66 g, 6.17 mmol) in methanol (10 ml) was added slowly to the reaction mixture, and stirred for 30 m at 268 K. The resulting mixture was neutralised with a saturated aqueous solution of NaHCO₃. A crude yellow-orange was separated by filtration and washed with small portions of water. The product was purified by flash chromatography on neutral alumina (hexane/ethyl acetate, 1:9), and recrystallized from an ethyl acetate/hexane mixture (9 : 1). Orange bar-shaped crystals of (I), suitable for X-ray analysis, were obtained by slow evaporation of the solvent mixture. Yield 47% (0.87 g, 2.90 mmol), based on 2-[4,5-dihydro-1,3-oxazol-2-yl]aniline; m.p., 111–113 °C. IR (KBr pellet, cm^-1), 3278, 3233, 1625, 1538, 1269.¹H NMR [(CD₃)₂CO, 200 MHz] δ 12.89 (s), 8.10 (s), 7.93–7.02 (m, 8H), 4.10 (s), 3.74 (dd J = 5.4, 11.0 Hz, 2H), 3.54 (dd, J = 5.4, 11.0 Hz, 2H), 2.35 (s, 3H).¹³C NMR [(C D₃)₂CO, 50 MHz] δ 135.4, 133.0, 130.1, 128.4, 121.7,114.9, 61.2, 43.2, 21.0. Anal. Calcd. for C₁₆H₁₈N₄O₂: C, 64.41; H, 6.08;N, 18.78%. Found C, 64.11; H, 6.44; N, 18.93%. HRESIMS Calcd. for [M+H]⁺299.1503. Found 299.1519.