3-(2H-Benzotriazol-2-yl)-2-hydr­oxy-5-methyl­benzaldehyde

Chen-Yu Li; Chen-Yen Tsai; Chia-Her Lin; Bao-Tsan Ko

doi:10.1107/S1600536810007233

. 2010 Mar 3;66(Pt 4):o726. doi: 10.1107/S1600536810007233

3-(2H-Benzotriazol-2-yl)-2-hydroxy-5-methylbenzaldehyde

Chen-Yu Li ^a, Chen-Yen Tsai ^a, Chia-Her Lin ^a, Bao-Tsan Ko ^a,^*

PMCID: PMC2984053 PMID: 21580573

Abstract

In the title compound, C₁₄H₁₁N₃O₂, the dihedral angle between the mean planes of the benzotriazole ring system and the benzene ring of the salicylaldehyde group is 2.4 (2)°. There is an intramolecular O—H⋯N hydrogen bond which may influence the molecular conformation.

Related literature

For the application of N,N,O-tridentate Schiff-base metal complexes in the catalytic ring-opening polymerization of l-lactide, see: Wu et al. (2005 ▶); Chen et al. (2006 ▶). For a related structure, see: Li et al. (2009 ▶).

Experimental

Crystal data

C₁₄H₁₁N₃O₂
M _r = 253.26
Monoclinic,
a = 12.2724 (5) Å
b = 14.5018 (5) Å
c = 6.8897 (3) Å
β = 91.571 (2)°
V = 1225.71 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 296 K
0.34 × 0.31 × 0.23 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.972, T _max = 0.977
13912 measured reflections
2946 independent reflections
1657 reflections with I > 2σ(I)
R _int = 0.070

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.146
S = 1.01
2946 reflections
172 parameters
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT-Plus (Bruker, 2008 ▶); data reduction: SAINT-Plus; 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/S1600536810007233/lh5003sup1.cif

e-66-0o726-sup1.cif^{(17.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810007233/lh5003Isup2.hkl

e-66-0o726-Isup2.hkl^{(144.6KB, 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
O1—H1A⋯N1	0.85	1.94	2.588 (2)	132

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Acknowledgments

We gratefully acknowledge the financial support in part from the National Science Council, Taiwan (NSC97-2113-M-033-005-MY2) and in part from the project of the specific research fields in Chung Yuan Christian University, Taiwan (No. CYCU-98-CR—CH).

supplementary crystallographic information

Comment

Recently, NNO-tridentate Schiff-base zinc (Zn) and magnesium (Mg) complexes have been attracting considerable attention, mainly due to their applications in the catalytic ring-opening polymerization of L-lactide (Wu et al., 2005; Chen et al., 2006). These NNO-tridentate Schiff-base ligands were easily prepared by condensation from primary amine with the pendant arm of the amino group and various substituted salicylaldehyde derivatives in the presence of MgSO₄. The additional amino group can be able to provide strong coordination to stabilize Zn or Mg atom and thereby stabilizes the zinc or magnesium alkoxide complex, without further disproportionation. Most recently, our group has successfully synthesized and structural characterized the amino-phenolate ligand derived from 4-methyl-2-(2H-benzotriazol-2-yl)-phenol (BTP-H) (Li et al., 2009). In order to develop more useful ligands originated from BTP derivates, our group is interested in the preparation of the multidentate Schiff-base ligand containing the benzotriazol group. Herein, we report the synthesis and crystal structure of the title compound, (I), a potential precursor for the preparation of the multidentate Schiff-base BTP ligands.

The molecular structure of (I) reveals the 5-methylsalicylaldehyde configuration with one benzotriazole functionalized group on the C2-position (Fig. 1). The dihedral angle between the planes of the benzotriazole unit and the benzene ring of the salicylaldehyde group is 2.4 (2)°. There is an intramolecular O—H···N hydrogen bond between the phenol and benzotriazole groups (Table 1). The distance of N1···H1A is substantially shorter than the van der Waals distance of 2.75 Å for the N and H distance. The distances in the benzotriazole-phenolate group are similar to those found in the crystal structure of 2-(2H-benzotriazol-2-yl)-6-((diethylamino)methyl)-4-methylphenol (Li et al., 2009).

Experimental

The title compound (I) was synthesized by the following procedures (Fig. 2): In a 100 ml round bottom flask was placed with 4-methyl-2-(2H-benzotriazol-2-yl)phenol (4.50 g, 20.0 mmol) and hexamethylenetetramine (5.60 g, 40 mmol). To this was added trifluoroacetic acid (24 ml, 0.30 mol) and the yellow solution became hot. The resulting mixture was heated to 418 K under reflux for 18 h, during which time the solution colour turned the yellow to dark brown/black. The hot solution was poured into 4 N HCl_(aq) (40 ml) and stirred for another 2 h, during which time the solids were formed. The mixture was placed at 253 K overnight and the solids were filtered. The mixture was then extracted with dichloromethane (3 x 150 ml) and the organic layers were dried over MgSO₄. The final solution was removed the solvent under vacuum to give yellow solids. Yield: 4.40 g (87 %). Single crystals suitable for X-ray diffraction were obtained from a saturated solution of the title compound in Et₂O.