3-(3-Chloro­benz­yl)-1H-isochromen-1-one

Obaid-Ur-Rehman Abid; Ghulam Qadeer; Nasim Hasan Rama; Ales Ruzicka; Zdenka Padelkova

doi:10.1107/S1600536808030274

. 2008 Sep 27;64(Pt 10):o2018. doi: 10.1107/S1600536808030274

3-(3-Chlorobenzyl)-1H-isochromen-1-one

Obaid-Ur-Rehman Abid ^a, Ghulam Qadeer ^a, Nasim Hasan Rama ^a,^*, Ales Ruzicka ^b, Zdenka Padelkova ^b

PMCID: PMC2959484 PMID: 21201213

Abstract

The asymmetric unit of the title compound, C₁₆H₁₁ClO₂, a chemically synthesized isocoumarin, contains three independent molecules. The benzopyran and benzene rings are approximately perpendicular to each other, forming dihedral angles ranging from 83.08 (14) to 87.43 (11)°. In the crystal structure, molecules are linked by intermolecular C—H⋯O hydrogen-bonding interactions, forming chains running parallel to the a axis.

Related literature

For the properties and applications of isocumarins, see: Barry (1964 ▶); Powers et al. (2002 ▶); Sturtz et al. (2002 ▶). For the crystal structure of a related compound, see: Abid et al. (2006 ▶). For related literature, see: Allen et al. (1987 ▶); Rossi et al. (2003 ▶); Thomas & Jens (1999 ▶). graphic file with name e-64-o2018-scheme1.jpg

Experimental

Crystal data

C₁₆H₁₁ClO₂
M _r = 270.70
Triclinic,
a = 8.1411 (8) Å
b = 15.0269 (14) Å
c = 16.4080 (16) Å
α = 91.696 (8)°
β = 98.478 (8)°
γ = 102.624 (6)°
V = 1933.4 (3) Å³
Z = 6
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 150 (1) K
0.36 × 0.28 × 0.13 mm

Data collection

Bruker–Nonius KappaCCD area-detector diffractometer
Absorption correction: Gaussian (Coppens et al., 1970 ▶) T _min = 0.930, T _max = 0.978
33806 measured reflections
8770 independent reflections
5387 reflections with I > 2σ(I)
R _int = 0.096

Refinement

R[F ² > 2σ(F ²)] = 0.093
wR(F ²) = 0.280
S = 1.15
8770 reflections
514 parameters
H-atom parameters constrained
Δρ_max = 0.51 e Å⁻³
Δρ_min = −0.38 e Å⁻³

Data collection: COLLECT (Hooft, 1998 ▶) and DENZO (Otwinowski & Minor, 1997 ▶); cell refinement: COLLECT and DENZO; 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 global, I. DOI: 10.1107/S1600536808030274/rz2245sup1.cif

e-64-o2018-sup1.cif^{(27.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808030274/rz2245Isup2.hkl

e-64-o2018-Isup2.hkl^{(428.9KB, 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
C216—H216⋯O11	0.93	2.56	3.437 (6)	158
C116—H116⋯O21	0.93	2.58	3.396 (6)	147
C26—H26⋯O22ⁱ	0.93	2.45	3.339 (7)	161
C36—H36⋯O32ⁱ	0.93	2.52	3.409 (6)	160

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors gratefully acknowledge the financial support of the Ministry of Education of the Czech Republic (Project VZ0021627501) and the 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 halo-isocoumarins and their halogeno-3,4-dihydroiscoumarin 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 isocoumarine derivative containing a 3-chlorobenzyl substituent, has been synthesized and its crystal structure is reported here.

The asymmetric unit of the title compound contains three crystallographically independent molecules of similar geometry (Fig.1). The molecules are not planar, the dihedral angles formed by the benzopyran ring with the corresponding benzene ring being 83.08 (14), 87.43 (11) and 84.25 (14)° for the molecules containing Cl11, Cl21 and Cl31, respectively. The bond lengths (Allen et al., 1987) and angles are within normal ranges and comparable with those reported for 3-(2-chlorobenzyl)isocoumarin (Abid et al., 2006). In the crystal packing, molecules are linked by intermolecular C—H···O hydrogen bonds (Table 1) into chains running parallel to the a axis (Fig. 2).

Experimental

A mixture of 2-(3-chlorophenyl)acetic acid (4.76 g, 28 mmol) and thionyl chloride (2.94 ml, 34 mmol) was heated for 30 min in the presence of a few drops of DMF under reflux at 343 K to give 2-(3-chlorophenyl)acetyl chloride. Completion of the reaction was indicated by the disappearance of gas evolution. The removal of excess thionyl chloride was carried out under reduced pressure to afford 2-(3-chlorophenyl)acetyl chloride. Homophthalic acid (1.3 g, 7.2 mmol) was then added and the solution was refluxed for 6 hrs at 473 K with stirring. The reaction mixture was extracted with ethyl acetate (3 times 100 ml), and an aqueous solution of sodium carbonate (5%, 200 ml) was added to remove the unreacted homophthalic acid. The organic layer was separated, concentrated and chromatographed on silica gel using petroleum ether (313–353 K fractions) as eluent to afford the title compound (yield 62%; m.p. 350–351 K). Colourless single crystals suitable for X-ray analysis were obtained by slow evaporation of an ethyl acetate solution.