5-Chloro-2-hy­droxy­benzoic acid

Abdul Rauf Raza; Bushra Nisar; M Nawaz Tahir; Ahmad Raza

doi:10.1107/S1600536810042042

. 2010 Oct 23;66(Pt 11):o2921. doi: 10.1107/S1600536810042042

5-Chloro-2-hydroxybenzoic acid

Abdul Rauf Raza ^a, Bushra Nisar ^a, M Nawaz Tahir ^b,^*, Ahmad Raza ^a

PMCID: PMC3008994 PMID: 21589095

Abstract

The asymmetric unit of the title compound, C₇H₅ClO₃, contains two molecules; both feature an intramolecular O—H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, both molecules form inversion dimers linked by pairs of O—H⋯O hydrogen bonds with R ₂ ²(8) ring motifs. The dimers are interlinked by C—H⋯O interactions.

Related literature

For biological background, see: Bright et al. (2010 ▶): Fattorusso et al. (2005 ▶); Miki et al. (2002 ▶). For a related structure, see: Raza et al. (2010 ▶). For graph-set notation, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₇H₅ClO₃
M _r = 172.56
Monoclinic,
a = 23.526 (2) Å
b = 3.7972 (4) Å
c = 16.7321 (16) Å
β = 104.852 (5)°
V = 1444.8 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.48 mm⁻¹
T = 296 K
0.34 × 0.12 × 0.10 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.879, T _max = 0.888
14048 measured reflections
3697 independent reflections
2444 reflections with I > 2σ(I)
R _int = 0.047

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.138
S = 1.03
3697 reflections
211 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.50 e Å⁻³

Data collection: APEX2 (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: ORTEP-3 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810042042/hb5691sup1.cif

e-66-o2921-sup1.cif^{(17.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810042042/hb5691Isup2.hkl

e-66-o2921-Isup2.hkl^{(177.6KB, 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—H1⋯O2ⁱ	0.83 (3)	1.88 (3)	2.710 (2)	171 (3)
O3—H3⋯O2	0.80 (3)	1.92 (3)	2.620 (2)	146 (3)
O4—H4A⋯O5ⁱⁱ	0.93 (3)	1.76 (3)	2.694 (2)	175 (2)
O6—H6⋯O5	0.87 (3)	1.80 (3)	2.606 (2)	154 (3)
C5—H5⋯O6ⁱⁱⁱ	0.93	2.55	3.311 (3)	139

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

Acknowledgments

The authors acknowledge the provision of funds for the purchase of the diffractometer and encouragement by Dr Muhammad Akram Chaudhary, Vice Chancellor, University of Sargodha, Pakistan. ARR also acknowledges the Higher Education Commission, Government of Pakistan, for generous support of a research project (20–819).

supplementary crystallographic information

Comment

The benzoxazepines have a plethora of biological activities ranging from anti-inflammatory effect (Miki et al., 2002) to degenerative diseases like AIDS (Fattorusso et al., 2005) and cancer (Bright et al., 2010). Salicylic acid is an attractive substrate for the synthesis of 4,1-benzoxazepine. The objective of this work is to synthesize a variety of substituted salicylic acid derivatives as precursors for the asymmetric synthesis of 4,1-benzoxazepines by chiral-pool strategy.

We have reported the crystal structure of 2-methylamino-5-nitrobenzoic acid (Raza et al., 2010) and in continuation to synthesize substituted benzoic acid, the title compound (I, Fig. 1) is being reported.

The title compound consists of two molecules in the crystallographic asymmetric unit which differ from each other geometrically. Both molecules, A (C1—C7/O1/O2/O3/CL1) and B (C8—C14/O4/O5/O6/CL2) are close to planar with r. m. s deviations of 0.023 and 0.007 Å, respectively. The dihedral angle between A/B is 1.77 (4)°. In each molecule, there exists an S(6) ring motif (Bernstein et al., 1995) due to intramolecular H-bonding of O—H···O type (Table 1, Fig. 1). The molecules form dimers with themselves due to intermolecular H-bondings of O—H···O type (Table 1, Fig. 2) with R₂²(8) ring motifs. These dimers are interlinked with each other due to H-bonding of C—H···O type (Fig. 2).

Experimental

A solution of Cu₂Cl₂ (3.46 g, 0.0375 mol) in HCl (10 ml) was added as drops to the diazonium salt of 5-amino-2-hydroxybenzioc acid (3.825 g, 0.025 mol), which was prepared by adding ice chilled aqueous solution of NaNO₂ (2.58 g, 0.0375 mol) to the solution of 5-amino-2-hydroxybenzoic acid in EtOAc and H₂SO₄ (2.8 ml, 4.9 g, 0.05 mol). The temperature of the reaction mixture was controlled below 268 K. After the complete addition of Cu₂Cl₂, the reaction mixture was refluxed for one hour, cooled to room temperature, neutralized with aqueous NaHCO₃ (10%) and extracted with EtOAc (3 × 25 ml). The organic layer was combined, dried over anhydrous Na₂SO₄, filtered, concentrated under reduced pressure and left for 48 h to afford light yellow needles of (I).