organic compounds
1-(1-Benzofuran-2-yl)ethanone O-(2,6-difluorobenzyl)oxime
aDepartment of Organic Chemistry, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, ul. A. Jurasza 2, 85-089 Bydgoszcz, Poland, and bDepartment of Organic Chemistry, Poznan University of Medical Sciences, ul. Grunwaldzka 6, 60-780 Poznań, Poland
*Correspondence e-mail: akgzella@ump.edu.pl
In the title compound, C17H13F2NO2, the 2,2-difluorobenzyloxy residue assumes an E configuration with respect to the benzofuran system. The benzene ring makes a dihedral angle of 61.70 (4)° with the fused ring system (r.m.s. deviation = 0.008 Å). In the crystal, molecules are connected by weak C—H⋯F hydrogen bonds into chains extending parallel to the b-axis direction.
CCDC reference: 977737
Related literature
For background to antifungal agents, see: Benedetti & Bani (1999); Sheehan et al. (1999). For the biological activity of and their see: Attia et al. (2013); De Luca (2006); Emami et al. (2004); Karakurt et al. (2001); Massolini et al. (1993); Mixich & Thiele (1985). For the synthesis of the title compound, see: Demirayak et al. (2002).
Experimental
Crystal data
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Data collection: CrysAlis PRO (Agilent, 2011); cell CrysAlis PRO; data reduction: CrysAlis PRO; 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: WinGX (Farrugia, 2012) and PLATON (Spek, 2009).
Supporting information
CCDC reference: 977737
https://doi.org/10.1107/S1600536813034090/zs2281sup1.cif
contains datablocks I, publication_text. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536813034090/zs2281Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536813034090/zs2281Isup3.cml
1-(1-Benzofuran-2-yl)ethanone O-(2,6-difluorobenzyl)oxime was synthesized from 1-(benzofuran-2-yl)ethanone oxime and 2,6-difluorobenzyl bromide, according to the literature procedure of Demirayak et al. (2002). Crystals were obtained after crystallization from ethanol.
All H atoms were placed in idealized positions and were refined within the riding model approximation: Cmethyl—H = 0.96 Å, Cmethylene—H = 0.97 Å, C(sp2)—H = 0.93 Å; Uiso(H) = 1.2Ueq(C) or 1.5Ueq(C) for methyl H. The methyl group was refined as a rigid group which was allowed to rotate.
The increase in fungal infections and the gained resistance to the currently used drugs in recent years directed the studies on obtaining new antifungal drugs (Benedetti & Bani, 1999). After the discovery of oxiconazole (Sheehan et al., 1999), ether
became of interest and a number of were synthesized and found to be active against fungi (Attia et al., 2013; De Luca, 2006; Emami et al., 2004; Karakurt et al., 2001; Massolini et al., 1993; Mixich & Thiele, 1985). The investigation of the title compound was undertaken to confirm the E configuration of the molecule, proposed on the basis of spectroscopic data.The molecular structure of the title compound and the atom-labelling scheme is illustrated in Fig. 1. In this compound, the nine-membered benzofuran system is planar with an r.m.s. deviation of 0.0083 Å. The 2,6-difluorobenzyloxy moiety is in the E configuration with respect to the benzofuran system [torsion angle C2—C10—N12—O13: 178.89 (9)°]. The C10—N12 bond is antiperiplanar in relation to the O13—C14 bond [torsion angle C10—N12—O13—C14: 176.13 (10)°]. A similar observation has been made for bonds N12—O13 and C14—C15 [torsion angle N12—O13—C14—C15: 170.08 (10)°]. The planar benzofuran system and the phenyl ring form a dihedral angle of 61.70 (4)°.
The molecular packing in the
is stabilized by possible C7—H7···F22i non-classical intermolecular hydrogen bonds (Table 1) which link molecules into chains lying parallel to the b axis (Fig. 2).For background to antifungal agents, see: Benedetti & Bani (1999); Sheehan et al. (1999). For the biological activity of
and their see: Attia et al. (2013); De Luca (2006); Emami et al. (2004); Karakurt et al. (2001); Massolini et al. (1993); Mixich & Thiele (1985). For the synthesis of the title compound, see: Demirayak et al. (2002).Data collection: CrysAlis PRO (Agilent, 2011); cell
CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); 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: WinGX (Farrugia, 2012) and PLATON (Spek, 2009).C17H13F2NO2 | F(000) = 624 |
Mr = 301.28 | Dx = 1.424 Mg m−3 |
Monoclinic, P21/n | Melting point = 346–348 K |
Hall symbol: -P 2yn | Mo Kα radiation, λ = 0.71073 Å |
a = 7.36652 (17) Å | Cell parameters from 10469 reflections |
b = 17.0314 (4) Å | θ = 2.2–29.1° |
c = 11.2047 (2) Å | µ = 0.11 mm−1 |
β = 90.020 (2)° | T = 130 K |
V = 1405.76 (5) Å3 | Indefinite, colourless |
Z = 4 | 0.35 × 0.15 × 0.12 mm |
Agilent Xcalibur Atlas diffractometer | 3548 independent reflections |
Radiation source: Enhance (Mo) X-ray Source | 2887 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
Detector resolution: 10.3088 pixels mm-1 | θmax = 29.1°, θmin = 2.2° |
ω scans | h = −9→10 |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011) | k = −23→22 |
Tmin = 0.992, Tmax = 1.000 | l = −14→15 |
24335 measured reflections |
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)] = 0.041 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.099 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0434P)2 + 0.5216P] where P = (Fo2 + 2Fc2)/3 |
3548 reflections | (Δ/σ)max < 0.001 |
200 parameters | Δρmax = 0.26 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C17H13F2NO2 | V = 1405.76 (5) Å3 |
Mr = 301.28 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 7.36652 (17) Å | µ = 0.11 mm−1 |
b = 17.0314 (4) Å | T = 130 K |
c = 11.2047 (2) Å | 0.35 × 0.15 × 0.12 mm |
β = 90.020 (2)° |
Agilent Xcalibur Atlas diffractometer | 3548 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011) | 2887 reflections with I > 2σ(I) |
Tmin = 0.992, Tmax = 1.000 | Rint = 0.033 |
24335 measured reflections |
R[F2 > 2σ(F2)] = 0.041 | 0 restraints |
wR(F2) = 0.099 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.26 e Å−3 |
3548 reflections | Δρmin = −0.24 e Å−3 |
200 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 | ||
O1 | 0.16108 (11) | 0.14365 (5) | 0.55614 (7) | 0.0225 (2) | |
C2 | 0.01949 (16) | 0.13157 (7) | 0.47691 (11) | 0.0202 (2) | |
C3 | 0.05125 (18) | 0.16689 (7) | 0.37076 (11) | 0.0246 (3) | |
H3 | −0.0245 | 0.1667 | 0.3044 | 0.030* | |
C4 | 0.22538 (17) | 0.20490 (7) | 0.38062 (11) | 0.0228 (3) | |
C5 | 0.3345 (2) | 0.25081 (8) | 0.30607 (12) | 0.0292 (3) | |
H5 | 0.2964 | 0.2639 | 0.2295 | 0.035* | |
C6 | 0.50053 (19) | 0.27631 (8) | 0.34892 (13) | 0.0302 (3) | |
H6 | 0.5750 | 0.3065 | 0.3001 | 0.036* | |
C7 | 0.55844 (18) | 0.25753 (8) | 0.46421 (13) | 0.0294 (3) | |
H7 | 0.6711 | 0.2753 | 0.4902 | 0.035* | |
C8 | 0.45207 (18) | 0.21312 (8) | 0.54084 (13) | 0.0268 (3) | |
H8 | 0.4893 | 0.2009 | 0.6179 | 0.032* | |
C9 | 0.28652 (16) | 0.18797 (7) | 0.49543 (11) | 0.0208 (3) | |
C10 | −0.13574 (16) | 0.08676 (7) | 0.52060 (11) | 0.0199 (2) | |
C11 | −0.27542 (17) | 0.05873 (8) | 0.43335 (11) | 0.0246 (3) | |
H11A | −0.2468 | 0.0062 | 0.4088 | 0.037* | |
H11B | −0.2761 | 0.0926 | 0.3649 | 0.037* | |
H11C | −0.3929 | 0.0594 | 0.4704 | 0.037* | |
N12 | −0.13799 (14) | 0.07490 (6) | 0.63388 (9) | 0.0226 (2) | |
O13 | −0.29434 (11) | 0.03251 (5) | 0.66817 (8) | 0.0240 (2) | |
C14 | −0.28904 (17) | 0.02743 (9) | 0.79613 (11) | 0.0275 (3) | |
H14A | −0.2683 | 0.0789 | 0.8305 | 0.033* | |
H14B | −0.1917 | −0.0072 | 0.8213 | 0.033* | |
C15 | −0.46849 (16) | −0.00434 (7) | 0.83627 (10) | 0.0200 (2) | |
C16 | −0.62337 (17) | 0.04170 (7) | 0.83715 (11) | 0.0222 (3) | |
C17 | −0.79223 (18) | 0.01540 (9) | 0.87023 (12) | 0.0287 (3) | |
H17 | −0.8924 | 0.0486 | 0.8687 | 0.034* | |
C18 | −0.80877 (19) | −0.06188 (9) | 0.90588 (12) | 0.0316 (3) | |
H18 | −0.9222 | −0.0813 | 0.9272 | 0.038* | |
C19 | −0.6595 (2) | −0.11065 (8) | 0.91027 (12) | 0.0332 (3) | |
H19 | −0.6704 | −0.1624 | 0.9358 | 0.040* | |
C20 | −0.49296 (19) | −0.08056 (7) | 0.87563 (11) | 0.0252 (3) | |
F21 | −0.60530 (12) | 0.11776 (5) | 0.80385 (8) | 0.0363 (2) | |
F22 | −0.34453 (13) | −0.12699 (5) | 0.88276 (8) | 0.0428 (2) |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0189 (4) | 0.0270 (5) | 0.0216 (4) | −0.0037 (3) | 0.0001 (3) | 0.0006 (3) |
C2 | 0.0188 (6) | 0.0209 (6) | 0.0209 (6) | 0.0000 (4) | −0.0008 (5) | −0.0047 (4) |
C3 | 0.0256 (6) | 0.0270 (6) | 0.0211 (6) | −0.0050 (5) | −0.0012 (5) | −0.0009 (5) |
C4 | 0.0255 (6) | 0.0196 (6) | 0.0234 (6) | −0.0031 (5) | 0.0016 (5) | −0.0029 (4) |
C5 | 0.0362 (8) | 0.0257 (6) | 0.0257 (7) | −0.0078 (6) | 0.0016 (6) | 0.0011 (5) |
C6 | 0.0326 (7) | 0.0229 (6) | 0.0350 (7) | −0.0088 (5) | 0.0080 (6) | −0.0012 (5) |
C7 | 0.0219 (6) | 0.0255 (6) | 0.0407 (8) | −0.0061 (5) | 0.0002 (6) | −0.0051 (5) |
C8 | 0.0231 (6) | 0.0277 (7) | 0.0295 (7) | −0.0016 (5) | −0.0023 (5) | −0.0006 (5) |
C9 | 0.0207 (6) | 0.0174 (5) | 0.0244 (6) | −0.0004 (4) | 0.0041 (5) | −0.0018 (4) |
C10 | 0.0188 (6) | 0.0203 (6) | 0.0206 (6) | 0.0013 (4) | 0.0020 (5) | −0.0028 (4) |
C11 | 0.0253 (6) | 0.0271 (6) | 0.0213 (6) | −0.0052 (5) | −0.0005 (5) | −0.0023 (5) |
N12 | 0.0160 (5) | 0.0292 (6) | 0.0225 (5) | −0.0043 (4) | 0.0033 (4) | −0.0012 (4) |
O13 | 0.0174 (4) | 0.0369 (5) | 0.0178 (4) | −0.0076 (4) | 0.0023 (3) | 0.0005 (4) |
C14 | 0.0184 (6) | 0.0468 (8) | 0.0173 (6) | −0.0052 (5) | −0.0012 (5) | 0.0029 (5) |
C15 | 0.0181 (6) | 0.0286 (6) | 0.0134 (5) | −0.0020 (5) | −0.0008 (4) | 0.0004 (4) |
C16 | 0.0231 (6) | 0.0243 (6) | 0.0194 (6) | −0.0022 (5) | −0.0023 (5) | 0.0030 (4) |
C17 | 0.0185 (6) | 0.0426 (8) | 0.0249 (7) | −0.0001 (5) | 0.0006 (5) | −0.0031 (6) |
C18 | 0.0271 (7) | 0.0467 (8) | 0.0209 (6) | −0.0161 (6) | 0.0027 (5) | −0.0005 (6) |
C19 | 0.0520 (9) | 0.0264 (7) | 0.0212 (6) | −0.0149 (6) | −0.0030 (6) | 0.0039 (5) |
C20 | 0.0317 (7) | 0.0261 (6) | 0.0179 (6) | 0.0044 (5) | −0.0037 (5) | −0.0015 (5) |
F21 | 0.0375 (5) | 0.0264 (4) | 0.0449 (5) | 0.0016 (3) | −0.0033 (4) | 0.0099 (3) |
F22 | 0.0504 (6) | 0.0360 (5) | 0.0421 (5) | 0.0204 (4) | −0.0081 (4) | −0.0012 (4) |
O1—C9 | 1.3736 (14) | C11—H11B | 0.9600 |
O1—C2 | 1.3848 (15) | C11—H11C | 0.9600 |
C2—C3 | 1.3534 (17) | N12—O13 | 1.4127 (13) |
C2—C10 | 1.4594 (17) | O13—C14 | 1.4369 (15) |
C3—C4 | 1.4410 (18) | C14—C15 | 1.4977 (17) |
C3—H3 | 0.9300 | C14—H14A | 0.9700 |
C4—C9 | 1.3929 (18) | C14—H14B | 0.9700 |
C4—C5 | 1.3986 (18) | C15—C20 | 1.3828 (18) |
C5—C6 | 1.384 (2) | C15—C16 | 1.3844 (17) |
C5—H5 | 0.9300 | C16—F21 | 1.3547 (14) |
C6—C7 | 1.397 (2) | C16—C17 | 1.3732 (18) |
C6—H6 | 0.9300 | C17—C18 | 1.381 (2) |
C7—C8 | 1.3870 (19) | C17—H17 | 0.9300 |
C7—H7 | 0.9300 | C18—C19 | 1.379 (2) |
C8—C9 | 1.3890 (18) | C18—H18 | 0.9300 |
C8—H8 | 0.9300 | C19—C20 | 1.385 (2) |
C10—N12 | 1.2853 (16) | C19—H19 | 0.9300 |
C10—C11 | 1.4972 (17) | C20—F22 | 1.3517 (15) |
C11—H11A | 0.9600 | ||
C9—O1—C2 | 105.72 (9) | H11A—C11—H11B | 109.5 |
C3—C2—O1 | 111.52 (11) | C10—C11—H11C | 109.5 |
C3—C2—C10 | 131.52 (11) | H11A—C11—H11C | 109.5 |
O1—C2—C10 | 116.92 (10) | H11B—C11—H11C | 109.5 |
C2—C3—C4 | 106.64 (11) | C10—N12—O13 | 111.08 (10) |
C2—C3—H3 | 126.7 | N12—O13—C14 | 106.28 (9) |
C4—C3—H3 | 126.7 | O13—C14—C15 | 107.32 (10) |
C9—C4—C5 | 118.79 (12) | O13—C14—H14A | 110.3 |
C9—C4—C3 | 105.39 (11) | C15—C14—H14A | 110.3 |
C5—C4—C3 | 135.82 (13) | O13—C14—H14B | 110.3 |
C6—C5—C4 | 118.45 (13) | C15—C14—H14B | 110.3 |
C6—C5—H5 | 120.8 | H14A—C14—H14B | 108.5 |
C4—C5—H5 | 120.8 | C20—C15—C16 | 114.96 (11) |
C5—C6—C7 | 121.23 (12) | C20—C15—C14 | 123.38 (12) |
C5—C6—H6 | 119.4 | C16—C15—C14 | 121.67 (11) |
C7—C6—H6 | 119.4 | F21—C16—C17 | 118.38 (12) |
C8—C7—C6 | 121.65 (12) | F21—C16—C15 | 117.30 (11) |
C8—C7—H7 | 119.2 | C17—C16—C15 | 124.32 (12) |
C6—C7—H7 | 119.2 | C16—C17—C18 | 117.97 (13) |
C7—C8—C9 | 115.95 (13) | C16—C17—H17 | 121.0 |
C7—C8—H8 | 122.0 | C18—C17—H17 | 121.0 |
C9—C8—H8 | 122.0 | C19—C18—C17 | 120.94 (12) |
O1—C9—C8 | 125.36 (12) | C19—C18—H18 | 119.5 |
O1—C9—C4 | 110.72 (10) | C17—C18—H18 | 119.5 |
C8—C9—C4 | 123.92 (12) | C18—C19—C20 | 118.26 (12) |
N12—C10—C2 | 115.07 (11) | C18—C19—H19 | 120.9 |
N12—C10—C11 | 125.85 (11) | C20—C19—H19 | 120.9 |
C2—C10—C11 | 119.08 (11) | F22—C20—C15 | 117.55 (12) |
C10—C11—H11A | 109.5 | F22—C20—C19 | 118.92 (12) |
C10—C11—H11B | 109.5 | C15—C20—C19 | 123.51 (12) |
C9—O1—C2—C3 | −0.51 (13) | O1—C2—C10—C11 | −168.36 (10) |
C9—O1—C2—C10 | −178.77 (10) | C2—C10—N12—O13 | 178.89 (9) |
O1—C2—C3—C4 | −0.06 (14) | C11—C10—N12—O13 | −1.33 (17) |
C10—C2—C3—C4 | 177.86 (12) | C10—N12—O13—C14 | −176.13 (10) |
C2—C3—C4—C9 | 0.60 (14) | N12—O13—C14—C15 | 170.08 (10) |
C2—C3—C4—C5 | −179.29 (15) | O13—C14—C15—C20 | 105.09 (13) |
C9—C4—C5—C6 | 1.18 (19) | O13—C14—C15—C16 | −75.36 (15) |
C3—C4—C5—C6 | −178.95 (14) | C20—C15—C16—F21 | 177.47 (11) |
C4—C5—C6—C7 | −0.5 (2) | C14—C15—C16—F21 | −2.12 (17) |
C5—C6—C7—C8 | −0.4 (2) | C20—C15—C16—C17 | −2.02 (18) |
C6—C7—C8—C9 | 0.70 (19) | C14—C15—C16—C17 | 178.39 (12) |
C2—O1—C9—C8 | −179.21 (12) | F21—C16—C17—C18 | −178.97 (11) |
C2—O1—C9—C4 | 0.91 (13) | C15—C16—C17—C18 | 0.5 (2) |
C7—C8—C9—O1 | −179.90 (11) | C16—C17—C18—C19 | 1.2 (2) |
C7—C8—C9—C4 | −0.03 (19) | C17—C18—C19—C20 | −1.3 (2) |
C5—C4—C9—O1 | 178.96 (11) | C16—C15—C20—F22 | −176.55 (11) |
C3—C4—C9—O1 | −0.95 (13) | C14—C15—C20—F22 | 3.03 (18) |
C5—C4—C9—C8 | −0.92 (19) | C16—C15—C20—C19 | 1.93 (18) |
C3—C4—C9—C8 | 179.17 (12) | C14—C15—C20—C19 | −178.49 (12) |
C3—C2—C10—N12 | −166.39 (13) | C18—C19—C20—F22 | 178.09 (12) |
O1—C2—C10—N12 | 11.44 (16) | C18—C19—C20—C15 | −0.4 (2) |
C3—C2—C10—C11 | 13.8 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
C7—H7···F22i | 0.93 | 2.54 | 3.3537 (16) | 147 |
Symmetry code: (i) −x+1/2, y+1/2, −z+3/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C7—H7···F22i | 0.93 | 2.54 | 3.3537 (16) | 147 |
Symmetry code: (i) −x+1/2, y+1/2, −z+3/2. |
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The increase in fungal infections and the gained resistance to the currently used drugs in recent years directed the studies on obtaining new antifungal drugs (Benedetti & Bani, 1999). After the discovery of oxiconazole (Sheehan et al., 1999), ether oximes became of interest and a number of oximes were synthesized and found to be active against fungi (Attia et al., 2013; De Luca, 2006; Emami et al., 2004; Karakurt et al., 2001; Massolini et al., 1993; Mixich & Thiele, 1985). The crystal structure investigation of the title compound was undertaken to confirm the E configuration of the molecule, proposed on the basis of spectroscopic data.
The molecular structure of the title compound and the atom-labelling scheme is illustrated in Fig. 1. In this compound, the nine-membered benzofuran system is planar with an r.m.s. deviation of 0.0083 Å. The 2,6-difluorobenzyloxy moiety is in the E configuration with respect to the benzofuran system [torsion angle C2—C10—N12—O13: 178.89 (9)°]. The C10—N12 bond is antiperiplanar in relation to the O13—C14 bond [torsion angle C10—N12—O13—C14: 176.13 (10)°]. A similar observation has been made for bonds N12—O13 and C14—C15 [torsion angle N12—O13—C14—C15: 170.08 (10)°]. The planar benzofuran system and the phenyl ring form a dihedral angle of 61.70 (4)°.
The molecular packing in the crystal lattice is stabilized by possible C7—H7···F22i non-classical intermolecular hydrogen bonds (Table 1) which link molecules into chains lying parallel to the b axis (Fig. 2).