Abstract
C11H7BrO4, triclinic, P1̄ (no. 2), a = 4.3164(5) Å, b = 10.7922(12) Å, c = 11.1521(11) Å, α = 98.075(4)°, β = 100.741(4)°, γ = 95.325(5)°, V = 501.55(9) Å3, Z = 2, Rgt(F) = 0.0203, wRref(F2) = 0.0544, T = 200(2) K.
The crystal structure is shown in the figure. Table 1 contains crystallographic data and Table 2 contains the list of the atoms including atomic coordinates and displacement parameters.
Data collection and handling.
| Crystal: | Rod, colorless |
| Size: | 0.52 × 0.10 × 0.06 mm |
| Wavelength: | Mo Kα radiation (0.71073 Å) |
| μ: | 4.09 mm−1 |
| Diffractometer, scan mode: | Bruker APEX-II, φ and ω-scans |
| θmax, completeness: | 28.3°, >99% |
| N(hkl)measured, N(hkl)unique, Rint: | 22323, 2483, 0.022 |
| Criterion for Iobs, N(hkl)gt: | Iobs > 2 σ(Iobs), 2286 |
| N(param)refined: | 147 |
| Programs: | Bruker programs [1], [2], SHELX [3], [4], PLATON [5], Mercury [6] |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2).
| Atom | x | y | z | Uiso*/Ueq |
|---|---|---|---|---|
| Br1 | 0.13721(4) | 0.17993(2) | 0.01884(2) | 0.03753(7) |
| O1 | 0.7786(3) | 0.13535(10) | 0.53551(10) | 0.0288(2) |
| O2 | 0.9251(3) | 0.20150(12) | 0.73466(11) | 0.0371(3) |
| O3 | 0.3131(3) | 0.48279(11) | 0.70865(11) | 0.0357(3) |
| O4 | 0.1861(3) | 0.40602(11) | 0.48776(11) | 0.0319(2) |
| H4 | 0.187571 | 0.452297 | 0.555097 | 0.048* |
| C1 | 0.7601(4) | 0.21857(15) | 0.64011(14) | 0.0268(3) |
| C2 | 0.5496(3) | 0.31471(14) | 0.62429(13) | 0.0246(3) |
| C3 | 0.3821(3) | 0.32300(13) | 0.50633(14) | 0.0242(3) |
| C4 | 0.4234(3) | 0.23887(14) | 0.40000(13) | 0.0233(3) |
| C5 | 0.2745(4) | 0.24839(15) | 0.27927(14) | 0.0266(3) |
| H5 | 0.140138 | 0.311862 | 0.264499 | 0.032* |
| C6 | 0.3262(4) | 0.16441(15) | 0.18292(14) | 0.0274(3) |
| C7 | 0.5157(4) | 0.06842(15) | 0.20280(15) | 0.0298(3) |
| H7 | 0.543009 | 0.009749 | 0.134778 | 0.036* |
| C8 | 0.6637(4) | 0.05881(15) | 0.32171(15) | 0.0289(3) |
| H8 | 0.793860 | −0.006008 | 0.336341 | 0.035* |
| C9 | 0.6186(3) | 0.14544(14) | 0.41908(14) | 0.0240(3) |
| C10 | 0.5063(4) | 0.40395(16) | 0.72819(15) | 0.0291(3) |
| C11 | 0.6796(5) | 0.4088(2) | 0.85630(16) | 0.0421(4) |
| H11A | 0.623638 | 0.329581 | 0.885067 | 0.063* |
| H11B | 0.621464 | 0.479164 | 0.909931 | 0.063* |
| H11C | 0.908764 | 0.421006 | 0.859012 | 0.063* |
Source of materials
All commercially available starting materials were used without further purification. A mixture of bromosalicylaldehyde (1 mol) and ethylacetoacetate (1 mol) were stirred in 30 mL of ethanol. Then the reaction mixture was cooled and ice-cold water was added. To this mixture 15 g of piperidine was added, in portions, with constant stirring. The mixture was then maintained at 0–5 °C for 3 hours and a white precipitate separated out which was filtered, washed with ethanol. The solid was recrystallized from water/hexane to obtain colourless rod crystals.
Experimental details
Carbon-bound H atoms were placed in calculated positions and were included in the refinement in the riding model approximation, with U(H) set to 1.2 Ueq(C). The H atoms of the methyl group were allowed to rotate with a fixed angle around the C—C bond to best fit the experimental electron density (HFIX 137 [2]), with Uiso(H) set to 1.5 Ueq(C).
Comment
Coumarin derivatives constitute the core structure of various natural products and are often the vital pharmacophore that originate in numerous medicinal agents such as antimicrobial, antifungal and antioxidant agents [7], [8]. Special properties of coumarin derivatives are of interest as targets to organic chemists and serve as intermediates in the synthesis of novel biological active compounds. In addition, certain derivatives of coumarins are known to induce apoptosis by cytochrome C release and caspase activation [9]. Recent reports describe some coumarin derivatives such as 7-hydroxy-coumarin [10], 7,8-diacetoxy-4-methylcoumarin and 7,8-diacetoxy-4-methyl-coumarin [11], [12] with selective cytotoxicity to cancer cells, which inhibit the growth of lung cancer cells without damaging the growth of normal peripheral blood mononuclear cells.
The title compound exhibits strong intramolecular hydrogen bonding of the O—H⋯O type between the hydroxy group and the ketonic O atom [O—O = 2.428(2) Å; see the figure]. The packing of crystal structure is dominated by weak intermolecular interactions. Additional π–π stacking interactions between adjacent rings (centroid distance is 3.331(2) Å) further stabilize the crystal.
Acknowledgements
This research project was funded by the South African Medical Research Council (MRC) and Antlantic Philantropies Scholarship (APS). The authors also thank the MRC for a bursary (to M.H.M) and APS for a bursary (to S.T.H.), Rhodes University. We also appreciate Rhodes University Research Council for financial support.
References
1. Bruker. SAINT (Version 7.68A), Bruker-AXS Inc., Madison, WI, USA (2012).Search in Google Scholar
2. Bruker. APEXII (2011.4-1) and SADABS (Version 2008/1), Bruker AXS Inc., Madison, WI, USA (2012).Search in Google Scholar
3. Sheldrick, G. M.: SHELXT – Integrated space-group and crystal-structure determination. Acta Crystallogr. A71 (2015) 3–8.10.1107/S2053273314026370Search in Google Scholar PubMed PubMed Central
4. Sheldrick, G. M.: Crystal structure refinement with SHELXL. Acta Crystallogr. C71 (2015) 3–8.10.1107/S2053229614024218Search in Google Scholar PubMed PubMed Central
5. Spek, A. L.: PLATON, molecular geometry program. J. Appl. Crystallogr. 36 (2003) 7–13.10.1107/S0021889802022112Search in Google Scholar
6. Macrae, C. F.; Bruno, I. J.; Chisholm, J. A.; Edgington, P. R.; McCabe, P.; Pidcock, E.; Rodriguez-Monge, L.; Taylor, R.; van de Streek, J.; Wood, P. A.: New features for the visualization and investigation of crystal structures. J. Appl. Cryst. 41 (2008) 466–470.10.1107/S0021889807067908Search in Google Scholar
7. Mladenovic, M.; Vukovic, N.; Niciforovic, N.; Sukdolak, S.; Solujic, S.: Synthesis and molecular descriptor characterization of novel 4-hydroxy-chromene-2-one derivatives as antimicrobial agents. Molecules 14 (2009) 1495–1512.10.3390/molecules14041495Search in Google Scholar PubMed PubMed Central
8. Al-Ayed, A. S.: Synthesis of new substituted chromen[4,3-c]pyrazol-4-ones and their antioxidant activities. Molecules 16 (2011) 10292–10302.10.3390/molecules161210292Search in Google Scholar PubMed PubMed Central
9. Johanssons, A.-C.; Steen, H.; Ollinger, K.; Roberg, K.: Cathepsin D mediates cytochrome c release and caspase activation in human fibroblast apoptosis induced by staurosporine. Cell Death Differ. 10 (2003) 1253–1259.10.1038/sj.cdd.4401290Search in Google Scholar PubMed
10. Gourdeau, H.; Leblond, L.; Hamelin, B.; Desputeau, C.; Dong, K.; Kianicka, I.; Custeau, D.; Bourdeau, C.; Geerts, L.; Cai, S.; Drewe, X. J.; Labrecque, D.; Kasibhatla, S.; Tseng, B.: Antivascular and antitumor evaluation of 2-amino-4-(3-bromo-4,5-dimethoxy-phenyl)-3-cyano-4H-chromenes, a novel series of anti-cancer agents. Mol. CancerTher. 3 (2004) 1375–1384.10.1158/1535-7163.1375.3.11Search in Google Scholar
11. Skommer, J.; Wlodkowic, D.; Matto, M.; Eray, M.: Pelkonen. HA14-1, a small molecule Bcl-2 antagonist, induces apoptosis and modulates action of selected anticancer drugs in follicular lymphoma B cells. J. Leukemia Res. 30 (2006) 322–331.10.1016/j.leukres.2005.08.022Search in Google Scholar PubMed
12. Patchett, A. A.; Nargund, R. P.: Privileged Structure – an update. Annu. Rep. Med. Chem. 35 (2000) 289–298.Search in Google Scholar
©2019 Siya T. Hulushe et al., published by De Gruyter, Berlin/Boston
This work is licensed under the Creative Commons Attribution 4.0 Public License.
