1-(1-Benzo­furan-2-yl)ethanone O-(2,6-di­fluoro­benz­yl)oxime

Kosmalski, T.; Gzella, A.K.

doi:10.1107/S1600536813034090

organic compounds

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ISSN: 2056-9890

Volume 70| Part 1| January 2014| Page o91

https://doi.org/10.1107/S1600536813034090

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1-(1-Benzofuran-2-yl)ethanone O-(2,6-difluorobenzyl)oxime

Tomasz Kosmalski ^a and Andrzej K. Gzella ^b ^*

^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

(Received 22 November 2013; accepted 17 December 2013; online 24 December 2013)

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 oximes and their ethers, 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

C₁₇H₁₃F₂NO₂
M_r = 301.28
Monoclinic, P 2₁ /n
a = 7.36652 (17) Å
b = 17.0314 (4) Å
c = 11.2047 (2) Å
β = 90.020 (2)°
V = 1405.76 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 130 K
0.35 × 0.15 × 0.12 mm

Data collection

Agilent Xcalibur Atlas diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 $[Agilent (2011). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]$ ) T_min = 0.992, T_max = 1.000
24335 measured reflections
3548 independent reflections
2887 reflections with I > 2σ(I)
R_int = 0.033

Refinement

R[F² > 2σ(F²)] = 0.041
wR(F²) = 0.099
S = 1.03
3548 reflections
200 parameters
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

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) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Data collection: CrysAlis PRO (Agilent, 2011 $[Agilent (2011). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]$ ); cell refinement: 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

Crystal structure: contains datablocks I, publication_text. DOI: https://doi.org/10.1107/S1600536813034090/zs2281sup1.cif

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

checkCIF report

Comment top

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).

Related literature top

For background to antifungal agents, see: Benedetti & Bani (1999); Sheehan et al. (1999). For the biological activity of oximes and their ethers, 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 top

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.

Structure description top

For background to antifungal agents, see: Benedetti & Bani (1999); Sheehan et al. (1999). For the biological activity of oximes and their ethers, 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).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: 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).

Figures top

	Fig. 1. The molecular structure of the title compound showing the atom labelling scheme. Non-H atoms are drawn as 30% probability displacement ellipsoids and H atoms are shown as small spheres of arbitrary radius.
	Fig. 2. The hydrogen bonding (dotted lines) in the title structure. For symmetry code (i), see Table 1. H atoms not involved in hydrogen-bonding have been omitted for clarity.

1-(1-Benzofuran-2-yl)ethanone O-(2,6-difluorobenzyl)oxime top

Crystal data top

C₁₇H₁₃F₂NO₂	F(000) = 624
M_r = 301.28	D_x = 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

Data collection top

Agilent Xcalibur Atlas diffractometer	3548 independent reflections
Radiation source: Enhance (Mo) X-ray Source	2887 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.033
Detector resolution: 10.3088 pixels mm^-1	θ_max = 29.1°, θ_min = 2.2°
ω scans	h = −9→10
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	k = −23→22
T_min = 0.992, T_max = 1.000	l = −14→15
24335 measured reflections

Refinement top

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(F_o²) + (0.0434P)² + 0.5216P] where P = (F_o² + 2F_c²)/3
3548 reflections	(Δ/σ)_max < 0.001
200 parameters	Δρ_max = 0.26 e Å⁻³
0 restraints	Δρ_min = −0.24 e Å⁻³

Crystal data top

C₁₇H₁₃F₂NO₂	V = 1405.76 (5) Å³
M_r = 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)°

Data collection top

Agilent Xcalibur Atlas diffractometer	3548 independent reflections
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	2887 reflections with I > 2σ(I)
T_min = 0.992, T_max = 1.000	R_int = 0.033
24335 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.041	0 restraints
wR(F²) = 0.099	H-atom parameters constrained
S = 1.03	Δρ_max = 0.26 e Å⁻³
3548 reflections	Δρ_min = −0.24 e Å⁻³
200 parameters

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
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)

Atomic displacement parameters (Å²) top

	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)

Geometric parameters (Å, º) top

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)

Hydrogen-bond geometry (Å, º) top

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.

Hydrogen-bond geometry (Å, º) top

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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