3-Bromo­chroman-4-one

Mahidansha M Shaikh; Neil A Koorbanally; Karen Du Toit; Deresh Ramjugernath; Johannes Bodenstein

doi:10.1107/S1600536813005394

. 2013 Mar 2;69(Pt 4):o473. doi: 10.1107/S1600536813005394

3-Bromochroman-4-one

Mahidansha M Shaikh ^a, Neil A Koorbanally ^a,^*, Karen Du Toit ^b, Deresh Ramjugernath ^c, Johannes Bodenstein ^b

PMCID: PMC3629513 PMID: 23634031

Abstract

The heterocyclic ring of the title compound, C₉H₇BrO₂, obtained by bromination of 4-chromanone with copper bromide, adopts a half-chair conformation. The supramolecular structure is governed by a weak C—H⋯O hydrogen bond. There is also π–π stacking between symmetry-related benzene rings; the centroid–centroid distance is 3.9464 (18), the perpendicular distance between the rings is 3.4703 (11) and the offset is 1.879 Å.

Related literature

For similar structures, see: Schollmeyer et al. (2005 ▶); Piel et al. (2011 ▶); Betz et al. (2011 ▶). For synthesis involving chromanone intermediates, see: Simas et al. (2002 ▶); Zhang et al. (2008 ▶). For the biological activity of chromanone derivatives, see: Cho et al. (1996 ▶); Xu et al. (1998 ▶); Shaikh et al. (2012 ▶, 2013a ▶,b ▶).

Experimental

Crystal data

C₉H₇BrO₂
M _r = 227.06
Monoclinic,
a = 10.0846 (7) Å
b = 7.9104 (6) Å
c = 10.9330 (8) Å
β = 110.164 (2)°
V = 818.71 (10) Å³
Z = 4
Mo Kα radiation
μ = 4.97 mm⁻¹
T = 173 K
0.16 × 0.12 × 0.12 mm

Data collection

Bruker Kappa DUO APEXII diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1997 ▶) T _min = 0.504, T _max = 0.587
5434 measured reflections
1659 independent reflections
1392 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.025
wR(F ²) = 0.061
S = 1.05
1659 reflections
109 parameters
H-atom parameters constrained
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.39 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: SAINT (Bruker, 2006 ▶); 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 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Click here for additional data file.^{(14.9KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536813005394/go2082sup1.cif

e-69-0o473-sup1.cif^{(14.9KB, cif)}

Click here for additional data file.^{(81.8KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813005394/go2082Isup2.hkl

e-69-0o473-Isup2.hkl^{(81.8KB, hkl)}

Click here for additional data file.^{(3.1KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813005394/go2082Isup3.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—H2A⋯O2ⁱ	0.99	2.44	3.311 (3)	146

Open in a new tab

Symmetry code: (i) Inline graphic .

Acknowledgments

We thank the University of KwaZulu-Natal, the National Research Foundation (NRF) and the South African Research Chairs initiative of the Department of Science and Technology for financial support and Ms Hong Su for the data collection.

supplementary crystallographic information

Comment

Many chromanone derivatives are used as versatile intermediates in the synthesis of natural products such as flavanone, isoflavanone and homoisoflavanones (Simas et al., 2002, Zhang et al., 2008). These derivatives possess anticancer and antibiotic properties (Cho et al., 1996.). Chromanone derivatives also possess antiviral activities against HIV and the simian immunodeficiency virus (SIV) (Xu et al., 1998). We recently reported the synthesis of several homoisoflavanone analogues from their corresponding chromanone derivatives with antiinflammatory (Shaikh et al., 2012; Shaikh et al., 2013a) and antifungal activities (Shaikh et al., 2013b).

In the title compound, the pyranone moiety is fused with the benzene ring and adopts a half chair conformation. The dihedral angle between the benzene ring and the (C₃—C₂—O₁) of the pyranone moiety is 43.03 (17)° and C2 flips out of the plane of the benzene ring by 0.5734 (31) Å (Fig. 1).

The supramolecular structure is governed by a weak C-H···O hydrogen bond, C2 –H2A···.O2 (-x,1-y,-z) with an H···O distance of 2.44 Å, a C···O distance of 3.311 (3)Å and an angle at H of 146°.

There is also π–π stacking between the two benzene rings across the centre-of-symmetry at (1/2,1/2,0), the centroid to centroid distance is 3.9464 (18)Å, the perpendicular distance between the rings is 3.4703 (11)Å and the offset is 1.879Å.

Experimental

To a mixture of copper bromide (II) (11.351 g, 50.673 mmol) in ethyl acetate, chloroform (20:20 ml) was stirred under inert atmosphere at room temperature. Into this mixture, chroman-4-one (5 g, 33.783 mmol) in chloroform (20 ml) was added and the reaction mixture refluxed vigorously under inert atmosphere at 70 °C for 6 h. Completion of the reaction was monitored by thin layer chromatography. Upon completion, the reaction mixture was cooled, filtered and washed with chloroform (20 ml). The filtrate solution was evaporated under reduced pressure to get the pure title compound with a yield of 86%.

¹H NMR (400 MHz, CDCl₃): δ (p.p.m.): 4.53–4.65 (3H, m, H-2a, H-2 b & H-3), 6.98–7.06 (2H, m, H-6 & H-8), 7.48–7.52 (1H, m, H-7), 7.89 (1H, dd, J = 1.60, 7.92 Hz, H-5).

¹³C NMR (400 MHz, CDCl₃): δ (p.p.m.): 45.43 (C-3), 71.26 (C-2), 117.95 (C-8), 11877 (C-10), 122.33 (C-6), 128.24 (C-7), 136.74 (C-5), 160.65 (C-9), 185.21 (C-4).