8-Bromo-3-phenyl-3a,4-dihydro-3H-chromeno[4,3-c]isoxazole-3a-carbo­nitrile

G Suresh; J Srinivasan; M Bakthadoss; S Aravindhan

doi:10.1107/S1600536813002511

. 2013 Jan 31;69(Pt 2):o312. doi: 10.1107/S1600536813002511

8-Bromo-3-phenyl-3a,4-dihydro-3H-chromeno[4,3-c]isoxazole-3a-carbonitrile

G Suresh ^a, J Srinivasan ^b, M Bakthadoss ^b, S Aravindhan ^a,^*

PMCID: PMC3569831 PMID: 23424577

Abstract

In the title compound, C₁₇H₁₁BrN₂O₂, the five-membered isoxazole ring has an envelope conformation with the C atom bearing the phenyl ring as the flap. The pyran ring has a half-chair conformation. In the chromeno ring system, the dihedral angle between the mean plane of the pyran ring and the benzene ring is 4.68 (2)°. The dihedral angle between the mean planes of the chromeno ring system and the isoxazole ring is 13.79 (15)°. The latter forms a dihedral angle of 34.10 (17)° with the phenyl ring. In the crystal, molecules are linked by C—H⋯N hydrogen bonds, forming an undulating two-dimensional network parallel to the ab plane.

Related literature

For the biological importance of 4H-chromene derivatives, see: Cai (2007 ▶, 2008 ▶); Cai et al. (2006 ▶); Caine (1993 ▶); Gabor (1988 ▶); Brooks (1998 ▶); Valenti et al. (1993 ▶); Hyana & Saimoto (1987 ▶); Tang et al. (2007 ▶). For related structures, see: Gangadharan et al. (2011 ▶); Swaminathan et al. (2011 ▶). For puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₇H₁₁BrN₂O₂
M _r = 355.19
Monoclinic,
a = 15.1034 (8) Å
b = 6.0676 (3) Å
c = 16.0865 (10) Å
β = 99.953 (2)°
V = 1452.00 (14) Å³
Z = 4
Mo Kα radiation
μ = 2.84 mm⁻¹
T = 298 K
0.35 × 0.28 × 0.20 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.437, T _max = 0.601
9947 measured reflections
3175 independent reflections
2214 reflections with I > 2σ(I)
R _int = 0.031

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.102
S = 1.09
3175 reflections
199 parameters
H-atom parameters constrained
Δρ_max = 0.68 e Å⁻³
Δρ_min = −0.96 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); 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 for Windows (Farrugia, 2012 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97 and PLATON.

Supplementary Material

Click here for additional data file.^{(18.5KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536813002511/su2547sup1.cif

e-69-0o312-sup1.cif^{(18.5KB, cif)}

Click here for additional data file.^{(152.6KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813002511/su2547Isup2.hkl

e-69-0o312-Isup2.hkl^{(152.6KB, hkl)}

Click here for additional data file.^{(5.5KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813002511/su2547Isup3.cml

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
C2—H2⋯N2ⁱ	0.93	2.62	3.519 (5)	164
C15—H15⋯N2ⁱⁱ	0.93	2.61	3.334 (5)	135

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

Acknowledgments

GS and SA thank UGC, India, for financial support. GS also thanks the SAIF, IIT-Madras, for for the instrumentation facility.

supplementary crystallographic information

Comment

4H-Chromenes are biologically important compounds used as synthetic ligands in the design of drugs and discovery processes. They exhibit numerous biological and pharmacological properties, such as anti-viral, anti-fungal, anti-inflammatory, anti- diabetic, cardionthonic, anti anaphylactic and anti-cancer activity (Cai, 2008, 2007; Cai et al., 2006; Gabor, 1988; Brooks, 1998; Valenti et al., 1993; Hyana & Saimoto, 1987; Tang et al., 2007). Chromenopyrrole compounds are used in the treatment of impulsive disorders (Caine, 1993). Continuing our interest in such compounds we have synthesized the title compound and report herein on its crystal structure.

The molecular structure of the title molecule is illustrated in Fig. 1. The five-membered isoxazole ring (N1/O2/C7/C8/C6) adopts an envelope conformation with atom C7 as the flap: puckering parameters (Cremer & Pople, 1975) being q2 = 0.28795 (2) Å and Φ = 143.4 (2)°. In the chromeno ring system, the dihedral angle between the mean plane of the pyran ring and the benzene ring is 4.68 (2)°. The dihedral angle between the mean planes of the chromeno ring system (fusion of benzene and pyran rings) and the isoxazole ring is 13.79 (15)°. The isoxazole ring mean planes forms a dihedral angle of 34.10 (17)° with phenyl ring (C11—C16). The dihedral angle between the chromeno ring system mean plane and this phenyl ring is 25.42 (13)°. The atom Br1 deviates by 0.0379 (5) Å from the chromeno ring mean plane (O1,C1—C6/C8—C10). The geometric parameters of the title molecule agree well with those reported for closely related structures (Gangadharan et al., 2011; Swaminathan et al., 2011).

In the crystal, molecules are linked by intermolecular C—H···N hydrogen bonds forming an undulating two-dimensional network parallel to the ab plane (Fig. 2 and Table 1).

Experimental

To a solution of (E)-2-((4-bromo-2-((E)-(hydroxyimino)methyl)phenoxy)methyl) -3-phenylacrylonitrile (2 mmol) in CCl₄ at 273 - 283 K was added pinch wise NCS (4 mmol) over 3 h. After Et₃N (4 mmol) was added to the reaction mixture which was stirred at room temperature for 2 h. After completion of the reaction, the mixture was evaporated under reduced pressure and the resulting crude mass was diluted with water (15 ml) and extracted with ethyl acetate (3 × 15 ml). The combining organic layer was washed with brine (2 × 10 ml) and dried over anhydrous Na₂SO₄. The organic layer was evaporated and purified by column chromatography (silica gel 60–120 mesh; 7% EtOAc in hexanes) to provide the desired pure title product as a colourless solid. Single crystals suitable for X-ray diffraction were obtained by slow evaporation of a solution of the title compound in ethyl acetate at room temperature.