organic compounds
of 1-(5-bromo-1-benzofuran-2-yl)ethanone oxime
aDept. of Studies and Research in Chemistry, University College of Science, Tumkur University, Tumkur 572103, India
*Correspondence e-mail: nirmaldb@rediffmail.com
The title compound, C10H8BrNO2, is almost planar (r.m.s. deviation for the non-H atoms = 0.031 Å) and the conformation across the C=N bond is trans. Further, the O atom of the benzofuran ring is syn to the N atom of the oxime group. In the crystal, inversion dimers linked by pairs of O—H⋯N hydrogen bonds generate R22(6) loops. Very weak aromatic π–π stacking interactions [centroid–centroid separations = 3.9100 (12) and 3.9447 (12) Å] are also observed.
Keywords: crystal structure; 1-(5-bromobenzofuran-2-yl) ethanone oxime; hydrogen bonding; π–π stacking interactions.
CCDC reference: 1425831
1. Related literature
For the various biological activities of the benzofuran moiety, see: Rida et al. (2006); Manna et al. (2010); Patil et al. (2010); Patel et al. (2006). For the antifungal activity of (benzofuran-2-yl) keoximes, see: Demirayak et al. (2002). For related structures, see: Aruna Kumar et al. (2014).
2. Experimental
2.1. Crystal data
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2.3. Refinement
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Data collection: APEX2 (Bruker, 2009); cell SAINT-Plus (Bruker, 2009); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97.
Supporting information
CCDC reference: 1425831
10.1107/S205698901501751X/hb7505sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S205698901501751X/hb7505Isup2.hkl
Supporting information file. DOI: 10.1107/S205698901501751X/hb7505Isup3.cml
The literature indicates that compounds having benzofuran nucleus possesses versatile pharmacological activities like anifungal, antiarrythmic, uricisuric, vasodilator and antimigraine agent (Rida et al., 2006; Manna et al., 2010; Patil et al., 2010; Patel et al., 2006). Further, (Benzofuran-2-yl) keoxime derivatives are known to show good antifungal activities (Demirayak et al., 2002). In view of the above and in continuation of our efforts to study the crystal structures of benzofuran moities (Aruna Kumar et al., 2014), the title compound was synthesized and its
was determined.The title compound (I), C10H8BrNO2, is almost planar (r.m.s. deviation for the non-H atoms = 0.031 Å) and the conformation across the C=N bond is trans in (I) (Figure 1). In contrast to this, the conformation across the C=N bond is syn in (1Z)-1-(1-Benzofuran-2-yl)ethanone oxime (II) (Aruna Kumar et al., 2014). Further, the O atom of the benzofuran ring is trans to the CH3 group in the side chain of (I), where as, in (II) (Aruna Kumar et al., 2014), it is syn. The torsions in the side chain of (I) have values: O1—C8—C9—N1 = 3.3 (3)o, C8—C9—N1—O2 = 179.41 (17)o and C7—C8—C9—C10 = 3.9 (4)o. The corresponding torsions in (II) have values 177.02 (16)o, 0.6 (3)o and 178.2 (2)o respectively (Aruna Kumar et al., 2014).
The π···π interactions, namely cg1···cg1 and cg1···cg2 (where cg1 is the centroid of the furan ring C4/C5/C7/C8/O1 and cg2 is the centroid of the aryl ring C1—C6) (Figure 2, Table 2), the centroid-centroid separations being 3.9447 (12) Å and 3.9100 (12) Å respectively.
features strong O2—H2A···N1 hydrogen bonds leading into R22(6) dimers, and these dimers are further interconnected via two5-bromo-2-acetylbenzofuran (1 g, 0.0062 mmol), hydroxylamine hydrochloride (0.65 g, 0.0093 mmol) and anhydrous K2CO3 (1.29 g, 0.0093 mmol) were taken in EtOH: H2O (3:1, 10 mL) and refluxed for 3 h. After the completion of the reaction, the reaction mixture was poured into ice cold water. The separated white solid was filtered, washed with water and dried. It was recrystallized from EtOH.
Colourless prisms were obtained from the solvent system: ethyl acetate: methanol (4:1) by slow evapouration technique.
Crystal data, data collection and structure
details are summarized in Table 1. The H atoms were positioned with idealized geometry using a riding model with C—H = 0.93–0.96 Å and O—H = 0.82 Å. The isotropic displacement parametersfor all H atoms were set to 1.2 times Ueq(Caromatic) and 1.5 times Ueq(Cmethyl, O).Data collection: APEX2 (Bruker, 2009); cell
SAINT-Plus (Bruker, 2009); data reduction: SAINT-Plus (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).C10H8BrNO2 | F(000) = 504 |
Mr = 254.08 | Prism |
Monoclinic, P21/n | Dx = 1.740 Mg m−3 |
Hall symbol: -P 2yn | Mo Kα radiation, λ = 0.71073 Å |
a = 5.9548 (6) Å | Cell parameters from 125 reflections |
b = 9.4897 (10) Å | θ = 3.5–29.9° |
c = 17.2906 (19) Å | µ = 4.21 mm−1 |
β = 96.943 (6)° | T = 296 K |
V = 969.91 (18) Å3 | Prism, colourless |
Z = 4 | 0.32 × 0.25 × 0.21 mm |
Bruker APEXII diffractometer | 1937 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.023 |
Graphite monochromator | θmax = 29.9°, θmin = 3.5° |
phi and φ scans | h = −8→7 |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | k = −13→10 |
Tmin = 0.294, Tmax = 0.413 | l = −18→24 |
10152 measured reflections | 1 standard reflections every 2 reflections |
2766 independent reflections | intensity decay: 0.5% |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.033 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.096 | H-atom parameters constrained |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0563P)2 + 0.0157P] where P = (Fo2 + 2Fc2)/3 |
2766 reflections | (Δ/σ)max = 0.001 |
129 parameters | Δρmax = 0.29 e Å−3 |
0 restraints | Δρmin = −0.33 e Å−3 |
C10H8BrNO2 | V = 969.91 (18) Å3 |
Mr = 254.08 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 5.9548 (6) Å | µ = 4.21 mm−1 |
b = 9.4897 (10) Å | T = 296 K |
c = 17.2906 (19) Å | 0.32 × 0.25 × 0.21 mm |
β = 96.943 (6)° |
Bruker APEXII diffractometer | 1937 reflections with I > 2σ(I) |
Absorption correction: multi-scan (SADABS; Bruker, 2009) | Rint = 0.023 |
Tmin = 0.294, Tmax = 0.413 | 1 standard reflections every 2 reflections |
10152 measured reflections | intensity decay: 0.5% |
2766 independent reflections |
R[F2 > 2σ(F2)] = 0.033 | 0 restraints |
wR(F2) = 0.096 | H-atom parameters constrained |
S = 1.01 | Δρmax = 0.29 e Å−3 |
2766 reflections | Δρmin = −0.33 e Å−3 |
129 parameters |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
C8 | 0.5278 (3) | −0.2686 (2) | −0.00305 (11) | 0.0391 (4) | |
C1 | 0.3056 (3) | 0.0480 (2) | 0.16815 (12) | 0.0447 (5) | |
C2 | 0.5215 (3) | 0.0179 (2) | 0.20434 (11) | 0.0492 (5) | |
H2 | 0.5745 | 0.0626 | 0.2509 | 0.059* | |
C3 | 0.6569 (3) | −0.0767 (2) | 0.17233 (12) | 0.0492 (5) | |
H3 | 0.8014 | −0.0979 | 0.1961 | 0.059* | |
C4 | 0.5691 (3) | −0.1394 (2) | 0.10298 (11) | 0.0390 (4) | |
C5 | 0.3543 (3) | −0.1120 (2) | 0.06601 (11) | 0.0403 (4) | |
C6 | 0.2169 (3) | −0.0159 (2) | 0.09927 (12) | 0.0470 (5) | |
H6 | 0.0714 | 0.0043 | 0.0761 | 0.056* | |
C7 | 0.3324 (3) | −0.1982 (2) | −0.00278 (12) | 0.0437 (5) | |
H7 | 0.2065 | −0.2041 | −0.0401 | 0.052* | |
C9 | 0.6021 (3) | −0.3724 (2) | −0.05598 (11) | 0.0412 (4) | |
C10 | 0.4500 (4) | −0.4102 (3) | −0.12802 (12) | 0.0513 (5) | |
H10A | 0.4955 | −0.3594 | −0.1716 | 0.077* | |
H10B | 0.2969 | −0.3859 | −0.1215 | 0.077* | |
H10C | 0.4598 | −0.5096 | −0.1373 | 0.077* | |
N1 | 0.7969 (3) | −0.42793 (19) | −0.03532 (10) | 0.0445 (4) | |
O1 | 0.6789 (2) | −0.23533 (16) | 0.06169 (8) | 0.0440 (3) | |
O2 | 0.8582 (2) | −0.52765 (17) | −0.08799 (9) | 0.0548 (4) | |
H2A | 0.9720 | −0.5695 | −0.0688 | 0.082* | |
Br1 | 0.13019 (4) | 0.18428 (3) | 0.214769 (13) | 0.05936 (13) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C8 | 0.0409 (10) | 0.0392 (10) | 0.0356 (10) | −0.0021 (8) | −0.0023 (7) | 0.0055 (8) |
C1 | 0.0505 (11) | 0.0403 (11) | 0.0447 (11) | 0.0004 (8) | 0.0111 (8) | 0.0024 (9) |
C2 | 0.0551 (12) | 0.0525 (13) | 0.0388 (11) | −0.0044 (10) | 0.0009 (8) | −0.0040 (9) |
C3 | 0.0452 (10) | 0.0586 (14) | 0.0412 (11) | −0.0014 (9) | −0.0058 (8) | −0.0012 (10) |
C4 | 0.0362 (9) | 0.0410 (11) | 0.0394 (10) | −0.0003 (8) | 0.0032 (7) | 0.0031 (8) |
C5 | 0.0401 (9) | 0.0391 (11) | 0.0405 (10) | −0.0005 (8) | 0.0002 (7) | 0.0062 (8) |
C6 | 0.0442 (10) | 0.0492 (12) | 0.0464 (12) | 0.0043 (9) | 0.0010 (8) | 0.0035 (9) |
C7 | 0.0391 (10) | 0.0498 (13) | 0.0403 (11) | 0.0035 (8) | −0.0037 (8) | −0.0002 (9) |
C9 | 0.0429 (10) | 0.0416 (11) | 0.0384 (10) | −0.0034 (8) | 0.0028 (8) | 0.0051 (9) |
C10 | 0.0520 (11) | 0.0552 (14) | 0.0444 (12) | 0.0022 (10) | −0.0030 (9) | −0.0011 (10) |
N1 | 0.0447 (9) | 0.0462 (10) | 0.0420 (9) | 0.0057 (7) | 0.0028 (7) | −0.0024 (7) |
O1 | 0.0379 (7) | 0.0496 (8) | 0.0420 (7) | 0.0041 (6) | −0.0052 (5) | −0.0014 (6) |
O2 | 0.0562 (9) | 0.0591 (10) | 0.0493 (8) | 0.0142 (7) | 0.0066 (6) | −0.0069 (7) |
Br1 | 0.0661 (2) | 0.05433 (19) | 0.06028 (19) | 0.00532 (9) | 0.01851 (12) | −0.00638 (10) |
C8—C7 | 1.343 (3) | C5—C6 | 1.394 (3) |
C8—O1 | 1.385 (2) | C5—C7 | 1.437 (3) |
C8—C9 | 1.449 (3) | C6—H6 | 0.9300 |
C1—C6 | 1.383 (3) | C7—H7 | 0.9300 |
C1—C2 | 1.390 (3) | C9—N1 | 1.285 (3) |
C1—Br1 | 1.901 (2) | C9—C10 | 1.493 (3) |
C2—C3 | 1.367 (3) | C10—H10A | 0.9600 |
C2—H2 | 0.9300 | C10—H10B | 0.9600 |
C3—C4 | 1.383 (3) | C10—H10C | 0.9600 |
C3—H3 | 0.9300 | N1—O2 | 1.392 (2) |
C4—O1 | 1.371 (2) | O2—H2A | 0.8200 |
C4—C5 | 1.384 (2) | ||
C7—C8—O1 | 111.24 (18) | C1—C6—C5 | 117.40 (17) |
C7—C8—C9 | 132.16 (16) | C1—C6—H6 | 121.3 |
O1—C8—C9 | 116.56 (17) | C5—C6—H6 | 121.3 |
C6—C1—C2 | 122.23 (19) | C8—C7—C5 | 107.11 (16) |
C6—C1—Br1 | 119.44 (15) | C8—C7—H7 | 126.4 |
C2—C1—Br1 | 118.33 (15) | C5—C7—H7 | 126.4 |
C3—C2—C1 | 120.75 (18) | N1—C9—C8 | 115.94 (16) |
C3—C2—H2 | 119.6 | N1—C9—C10 | 124.7 (2) |
C1—C2—H2 | 119.6 | C8—C9—C10 | 119.31 (17) |
C2—C3—C4 | 117.00 (18) | C9—C10—H10A | 109.5 |
C2—C3—H3 | 121.5 | C9—C10—H10B | 109.5 |
C4—C3—H3 | 121.5 | H10A—C10—H10B | 109.5 |
O1—C4—C3 | 125.70 (16) | C9—C10—H10C | 109.5 |
O1—C4—C5 | 110.89 (16) | H10A—C10—H10C | 109.5 |
C3—C4—C5 | 123.4 (2) | H10B—C10—H10C | 109.5 |
C4—C5—C6 | 119.22 (18) | C9—N1—O2 | 113.35 (16) |
C4—C5—C7 | 105.18 (17) | C4—O1—C8 | 105.58 (15) |
C6—C5—C7 | 135.61 (16) | N1—O2—H2A | 109.5 |
C6—C1—C2—C3 | 0.5 (3) | C9—C8—C7—C5 | 178.2 (2) |
Br1—C1—C2—C3 | −178.43 (16) | C4—C5—C7—C8 | −0.3 (2) |
C1—C2—C3—C4 | 0.2 (3) | C6—C5—C7—C8 | 179.5 (2) |
C2—C3—C4—O1 | 179.3 (2) | C7—C8—C9—N1 | −174.5 (2) |
C2—C3—C4—C5 | −0.6 (3) | O1—C8—C9—N1 | 3.3 (3) |
O1—C4—C5—C6 | −179.65 (18) | C7—C8—C9—C10 | 3.9 (4) |
C3—C4—C5—C6 | 0.3 (3) | O1—C8—C9—C10 | −178.38 (19) |
O1—C4—C5—C7 | 0.2 (2) | C8—C9—N1—O2 | 179.41 (17) |
C3—C4—C5—C7 | −179.9 (2) | C10—C9—N1—O2 | 1.1 (3) |
C2—C1—C6—C5 | −0.9 (3) | C3—C4—O1—C8 | −179.9 (2) |
Br1—C1—C6—C5 | 178.09 (15) | C5—C4—O1—C8 | 0.0 (2) |
C4—C5—C6—C1 | 0.4 (3) | C7—C8—O1—C4 | −0.3 (2) |
C7—C5—C6—C1 | −179.3 (2) | C9—C8—O1—C4 | −178.48 (16) |
O1—C8—C7—C5 | 0.4 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2A···N1i | 0.82 | 2.13 | 2.808 (2) | 140 |
Symmetry code: (i) −x+2, −y−1, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2A···N1i | 0.82 | 2.13 | 2.808 (2) | 140 |
Symmetry code: (i) −x+2, −y−1, −z. |
Footnotes
‡These authors contributed equally.
Acknowledgements
The authors are thankful to the Department of Science and Technology, New Delhi, Government of India for providing financial assistance under the DST FAST TRACK [SR/FT/CS-81/2010 (G)] scheme, and also thank Tumkur University for the administrative support to carry out the project.
References
Arunakumar, D. B., Nivedita, R. D., Sreenivasa, S., Madan Kumar, S., Lokanath, N. K. & Suchetan, P. A. (2014). Acta Cryst. E70, o40. CSD CrossRef IUCr Journals Google Scholar
Bruker (2009). APEX2, SADABS and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Demirayak, S., Ucucu, U., Benkli, K., Gundogdu-Karaburun, N. & Karaburun, A. C. (2002). II Farmaco, 57, 609–612. CrossRef CAS Google Scholar
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. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Manna, K. U. & Agrawal, Y. K. (2010). Eur. J. Med. Chem. 45, 3831–3839. CrossRef CAS PubMed Google Scholar
Patel, H. J., Sarra, J., Caruso, F., Rossi, M., Doshi, U. & Stephani, R. A. (2006). Bioorg. Med. Chem. Lett. 16, 4644–4647. CSD CrossRef PubMed CAS Google Scholar
Patil, S. L., Bhalgat, C. M., Burli, S. & Chithale, S. K. (2010). J. Chem. Sci Appl. 1, 42–49. CAS Google Scholar
Rida, S. M., El-Hawash, S. A. M., Fahmy, H. T., Hazzaa, A. A. & El-Meligy, M. M. M. (2006). Arch. Pharm. Res. 29, 826–833. CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
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