2-[(4-Chloro­benz­yl)carbonyl­meth­yl]benzoic acid

Obaid-ur-Rahman Abid; Ghulam Qadeer; Nasim Hasan Rama; Ales Ruzicka

doi:10.1107/S160053680803451X

. 2008 Oct 25;64(Pt 11):o2205. doi: 10.1107/S160053680803451X

2-[(4-Chlorobenzyl)carbonylmethyl]benzoic acid

Obaid-ur-Rahman Abid ^a, Ghulam Qadeer ^a,^*, Nasim Hasan Rama ^a, Ales Ruzicka ^b

PMCID: PMC2959499 PMID: 21581063

Abstract

The title compound, C₁₆H₁₃ClO₃, is an important intermediate in the conversion of isocoumarin to 3,4-dihydroisocoumarin. The two aromatic rings are oriented at a dihedral angle of 67.18 (3)°. In the crystal structure, intermolecular O—H⋯O hydrogen bonds link the molecules into centrosymmetric dimers. There is also a C—H⋯π contact between the benzoic acid and 4-chlorobenzyl rings.

Related literature

For a related structure, see: Abid et al. (2006 ▶). For general background, see: Barry (1964 ▶); Powers et al. (2002 ▶); Rossi et al. (2003 ▶); Sturtz et al. (2002 ▶); Thomas & Jens (1999 ▶). For bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₁₆H₁₃ClO₃
M _r = 288.71
Monoclinic,
a = 5.5000 (4) Å
b = 13.2720 (6) Å
c = 18.8120 (7) Å
β = 94.371 (4)°
V = 1369.21 (13) Å³
Z = 4
Mo Kα radiation
μ = 0.28 mm⁻¹
T = 150 (1) K
0.29 × 0.19 × 0.16 mm

Data collection

Bruker–Nonius Kappa CCD area-detector diffractometer
Absorption correction: integration (Coppens, 1970 ▶) T _min = 0.936, T _max = 0.962
10076 measured reflections
3010 independent reflections
2284 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.118
S = 1.14
3010 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.42 e Å⁻³

Data collection: COLLECT (Hooft, 1998 ▶); cell refinement: COLLECT and DENZO (Otwinowski & Minor, 1997 ▶); data reduction: COLLECT and DENZO; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2003 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680803451X/hk2557sup1.cif

e-64-o2205-sup1.cif^{(16.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680803451X/hk2557Isup2.hkl

e-64-o2205-Isup2.hkl^{(147.7KB, 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
O2—H2⋯O1ⁱ	0.82	1.81	2.626 (3)	176
C16—H16⋯Cg1ⁱⁱ	0.93	3.35	4.079 (3)	137

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Symmetry codes: (i) Inline graphic ; (ii) . Cg1 is the centroid of the C2–C7 ring.

Acknowledgments

The authors gratefully acknowledge the financial support of the Ministry of Education of the Czech Republic (project No. VZ0021627501) and Higher Education Commission, Islamabad, Pakistan.

supplementary crystallographic information

Comment

The isocoumarin nucleus is an abundant structural motif in natural products (Barry, 1964). Many constituents of the steadily growing class of known isocoumarins exhibit valuable biological properties such as antifungal (Sturtz et al., 2002), antitumor or cytotoxic, anti-inflammatory, anti-allergic (Rossi et al., 2003) and enzyme inhibitory activity (Powers et al., 2002). Naturally occurring haloisocoumarins and their halogeno-3,4-dihydroisocoumarin derivatives are very rare. However, a few examples of naturally occurring chlorine containing isocoumarins are known (Thomas & Jens, 1999). In view of the importance of this class of compounds, the title compound, an intermediate during the conversion of isocoumarin to 3,4-dihydroisocoumarin, has been synthesized, and we report herein its crystal structure.

In the title compound (Fig. 1), the bond lengths (Allen et al., 1987) and angles are within normal ranges, and comparable with the corresponding values in 3-(2-chlorobenzyl)isocoumarin (Abid et al., 2006). Rings A (C2-C7) and B (C11-C16) are, of course, planar and the dihedral angle between them is A/B = 67.18 (3)°. The intramolecular C-H···O hydrogen bonds (Table 1) result in the formation of nonplanar five- and six-membered rings C (O2/C1/C2/C7/H7) and D (O1/C1-C3/C8/H8B). Ring C adopts envelope conformation with C1 atom displaced by -0.108 (3) Å from the plane of the other ring atoms, while ring D has twisted conformation.

In the crystal structure, intermolecular O-H···O hydrogen bonds (Table 1) link the molecules into centrosymmetric dimers (Fig. 2), in which they may be effective in the stabilization of the structure. There also exist a C—H···π contact (Table 1) between the benzoic acid and 4-chlorobenzyl rings.

Experimental

A solution of 3-(4-chlorobenzyl)isocoumarin (2.0 g, 7 mmol) in ethanol (50 ml) and potassium hydroxide (100 ml, 5%) were refluxed for 4 h. Ethanol was removed from the reaction mixture by distillation. Ice cold water (20 ml) was added and the reaction mixture was acidified with hydrochloric acid. It was extracted with dichloromethane (3 × 20 ml), and then dried and evaporated to yield the crude solid, which was recrystallized from methanol (yield; 85%; m.p. 414-415 K).