5-Chloro-3-ethyl­sulfinyl-2-(4-fluoro­phen­yl)-1-benzofuran

In the title compound, C₁₆H₁₂ClFO₂S, the 4-fluoro­phenyl ring is rotated out of the benzofuran plane, as indicated by the dihedral angle of 6.96 (5)°. The crystal structure exhibits a Cl...O inter­action with a Cl...O distance of 3.163 (1) Å.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.033
• wR factor = 0.088
• Data-to-parameter ratio = 14.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT431_ALERT_2_C Short Inter HL..A Contact  Cl     ..  O2      ..       3.16 Ang.

Author Response: Mentioned as a halogen bond in the Abstract & Comment.

PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          2

Alert level G
PLAT154_ALERT_1_G The su's on the Cell Angles are Equal  (x 10000)        100 Deg.

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Molecules involving the benzofuran skeleton have received particular interest in view of their biological activities (Aslam et al., 2006; Galal et al., 2009; Howlett et al., 1999) and their occurrence as natural products (Akgul & Anil, 2003; Soekamto et al., 2003). As a part of our ongoing studies of the effect of side chain substituents on the solid state structures of 2-(4-fluorophenyl)-5-halo-3-methylsulfinyl-1-benzofuran analogues (Choi et al., 2010a,b,c), we report the crystal structure of the title compound (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.007 (1) Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle formed by the plane of the benzofuran and the 4-fluorophenyl ring is 6.96 (5)°. The crystal packing (Fig. 2) is stabilized by a Cl···O halogen bond between the chlorine and the oxygen of the S═O unit [Cl···O2ⁱ = 3.163 (1) Å; C—Cl···O2 = 168.98 (6)°] (Politzer et al., 2007).

Related literature

For the crystal structures of similar 2-(4-fluorophenyl)-5-halo-3-methylsulfinyl-1-benzofuran derivatives, see: Choi et al. (2010a,b,c). For the biological activity of benzofuran compounds, see: Aslam et al. (2006); Galal et al. (2009); Howlett et al. (1999). For natural products with benzofuran rings, see: Akgul & Anil (2003); Soekamto et al. (2003). For a review of halogen bonding, see: Politzer et al. (2007).

S2. Experimental

77% 3-Chloroperoxybenzoic acid (202 mg, 0.9 mmol) was added in small portions to a stirred solution of 5-chloro-3-ethylsulfanyl-2-(4-fluorophenyl)-1-benzofuran (245 mg, 0.8 mmol) in dichloromethane (30 mL) at 273 K. After being stirred at room temperature for 3h, the mixture was washed with saturated sodium bicarbonate solution and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (hexane–ethyl acetate, 2:1 v/v) to afford the title compound as a colorless solid [yield 81%, m.p. 413–414 K; R_f = 0.56 (hexane–ethyl acetate, 2:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in acetone at room temperature.

S3. Refinement

All H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93 Å for aryl, 0.97 Å for methylene, and 0.96 Å for methyl H atoms. U_iso(H) = 1.2U_eq(C) for aryl and methylene H atoms, and 1.5U_eq(C) for methyl H atoms.

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50 % probability level. H atoms are presented as a small spheres of arbitrary radius.
	Fig. 2. C—Cl···O interactions (dotted lines) in the crystal structure of the title compound. [Symmetry codes: (i) - x + 1, - y + 1, - z.]

5-Chloro-3-ethylsulfinyl-2-(4-fluorophenyl)-1-benzofuran

Crystal data

C16H12ClFO2S	Z = 2
Mr = 322.77	F(000) = 332
Triclinic, P1	Dx = 1.562 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.2843 (1) Å	Cell parameters from 8228 reflections
b = 9.4590 (1) Å	θ = 2.3–27.5°
c = 10.7717 (2) Å	µ = 0.44 mm^−1
α = 101.630 (1)°	T = 100 K
β = 99.301 (1)°	Block, colourless
γ = 104.471 (1)°	0.36 × 0.28 × 0.22 mm
V = 686.08 (2) Å^3

Data collection

Bruker SMART APEXII CCD diffractometer	2692 independent reflections
Radiation source: Rotating Anode	2549 reflections with I > 2σ(I)
Bruker HELIOS graded multilayer optics monochromator	Rint = 0.023
Detector resolution: 10.0 pixels mm^-1	θmax = 26.0°, θmin = 2.0°
φ and ω scans	h = −8→8
Absorption correction: multi-scan (SADABS; Bruker, 2009)	k = −11→11
Tmin = 0.685, Tmax = 0.746	l = −13→13
10971 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.033	Hydrogen site location: difference Fourier map
wR(F^2) = 0.088	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0438P)^2 + 0.4635P] where P = (Fo^2 + 2Fc^2)/3
2692 reflections	(Δ/σ)max < 0.001
190 parameters	Δρmax = 0.53 e Å^−3
0 restraints	Δρmin = −0.30 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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 (Ų)

	x	y	z	Uiso*/Ueq
S	0.45255 (6)	0.80712 (5)	0.40708 (4)	0.02482 (13)
Cl	0.28282 (7)	0.27078 (5)	−0.05264 (4)	0.03514 (14)
F	0.25946 (19)	0.84365 (15)	1.02077 (10)	0.0444 (3)
O1	0.20936 (16)	0.41731 (12)	0.48378 (11)	0.0220 (2)
O2	0.5927 (2)	0.79848 (16)	0.32129 (14)	0.0365 (3)
C1	0.3394 (2)	0.62050 (18)	0.41357 (15)	0.0206 (3)
C2	0.2984 (2)	0.48819 (18)	0.30777 (15)	0.0208 (3)
C3	0.3201 (2)	0.46061 (19)	0.17918 (16)	0.0237 (3)
H3	0.3723	0.5387	0.1430	0.028*
C4	0.2602 (2)	0.3116 (2)	0.10851 (16)	0.0258 (4)
C5	0.1846 (3)	0.1912 (2)	0.16042 (17)	0.0285 (4)
H5	0.1486	0.0927	0.1093	0.034*
C6	0.1631 (3)	0.21813 (19)	0.28749 (17)	0.0258 (4)
H6	0.1129	0.1399	0.3240	0.031*
C7	0.2202 (2)	0.36738 (18)	0.35738 (15)	0.0212 (3)
C8	0.2840 (2)	0.57255 (18)	0.51702 (16)	0.0206 (3)
C9	0.2817 (2)	0.64559 (19)	0.64935 (15)	0.0213 (3)
C10	0.2304 (2)	0.5573 (2)	0.73545 (17)	0.0261 (4)
H10	0.2019	0.4529	0.7085	0.031*
C11	0.2220 (3)	0.6242 (2)	0.86001 (17)	0.0304 (4)
H11	0.1849	0.5657	0.9166	0.036*
C12	0.2694 (3)	0.7788 (2)	0.89875 (16)	0.0304 (4)
C13	0.3240 (3)	0.8701 (2)	0.81899 (17)	0.0306 (4)
H13	0.3575	0.9745	0.8485	0.037*
C14	0.3279 (2)	0.8025 (2)	0.69353 (17)	0.0262 (4)
H14	0.3620	0.8624	0.6374	0.031*
C15	0.2417 (3)	0.8367 (2)	0.31295 (17)	0.0275 (4)
H15A	0.2831	0.9250	0.2801	0.033*
H15B	0.1812	0.7504	0.2390	0.033*
C16	0.0937 (3)	0.8588 (2)	0.39391 (19)	0.0300 (4)
H16A	0.1526	0.9452	0.4664	0.036*
H16B	0.0505	0.7708	0.4251	0.036*
H16C	−0.0155	0.8743	0.3413	0.036*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S	0.0245 (2)	0.0222 (2)	0.0283 (2)	0.00369 (16)	0.00953 (17)	0.00866 (16)
Cl	0.0472 (3)	0.0381 (3)	0.0213 (2)	0.0177 (2)	0.00961 (18)	0.00222 (18)
F	0.0576 (8)	0.0547 (8)	0.0209 (5)	0.0212 (6)	0.0129 (5)	0.0003 (5)
O1	0.0256 (6)	0.0205 (6)	0.0219 (6)	0.0071 (5)	0.0080 (4)	0.0070 (4)
O2	0.0333 (7)	0.0367 (7)	0.0437 (8)	0.0072 (6)	0.0211 (6)	0.0138 (6)
C1	0.0200 (8)	0.0200 (8)	0.0226 (8)	0.0061 (6)	0.0062 (6)	0.0059 (6)
C2	0.0187 (7)	0.0223 (8)	0.0226 (8)	0.0081 (6)	0.0050 (6)	0.0052 (6)
C3	0.0234 (8)	0.0275 (9)	0.0226 (8)	0.0098 (7)	0.0072 (6)	0.0071 (7)
C4	0.0265 (8)	0.0315 (9)	0.0214 (8)	0.0136 (7)	0.0063 (6)	0.0041 (7)
C5	0.0303 (9)	0.0240 (8)	0.0296 (9)	0.0114 (7)	0.0039 (7)	0.0012 (7)
C6	0.0274 (8)	0.0210 (8)	0.0303 (9)	0.0083 (7)	0.0068 (7)	0.0072 (7)
C7	0.0213 (8)	0.0234 (8)	0.0215 (8)	0.0095 (6)	0.0063 (6)	0.0062 (6)
C8	0.0187 (7)	0.0200 (8)	0.0241 (8)	0.0068 (6)	0.0051 (6)	0.0060 (6)
C9	0.0184 (7)	0.0258 (8)	0.0203 (8)	0.0075 (6)	0.0043 (6)	0.0057 (6)
C10	0.0275 (9)	0.0284 (9)	0.0242 (8)	0.0093 (7)	0.0067 (7)	0.0082 (7)
C11	0.0324 (9)	0.0401 (10)	0.0237 (9)	0.0131 (8)	0.0095 (7)	0.0135 (8)
C12	0.0298 (9)	0.0432 (11)	0.0183 (8)	0.0152 (8)	0.0057 (7)	0.0019 (7)
C13	0.0320 (9)	0.0289 (9)	0.0280 (9)	0.0096 (7)	0.0065 (7)	0.0005 (7)
C14	0.0271 (9)	0.0269 (9)	0.0248 (8)	0.0070 (7)	0.0077 (7)	0.0063 (7)
C15	0.0343 (9)	0.0255 (9)	0.0254 (8)	0.0103 (7)	0.0072 (7)	0.0100 (7)
C16	0.0256 (9)	0.0284 (9)	0.0375 (10)	0.0088 (7)	0.0076 (7)	0.0102 (7)

Geometric parameters (Å, º)

Cl—O2^i	3.163 (1)	C6—H6	0.9300
S—O2	1.489 (1)	C8—C9	1.458 (2)
S—C1	1.772 (2)	C9—C14	1.398 (2)
S—C15	1.8142 (18)	C9—C10	1.402 (2)
Cl—C4	1.745 (2)	C10—C11	1.381 (2)
F—C12	1.355 (2)	C10—H10	0.9300
O1—C7	1.370 (2)	C11—C12	1.373 (3)
O1—C8	1.381 (2)	C11—H11	0.9300
C1—C8	1.367 (2)	C12—C13	1.371 (3)
C1—C2	1.443 (2)	C13—C14	1.382 (2)
C2—C7	1.391 (2)	C13—H13	0.9300
C2—C3	1.399 (2)	C14—H14	0.9300
C3—C4	1.382 (2)	C15—C16	1.520 (2)
C3—H3	0.9300	C15—H15A	0.9700
C4—C5	1.398 (3)	C15—H15B	0.9700
C5—C6	1.383 (2)	C16—H16A	0.9600
C5—H5	0.9300	C16—H16B	0.9600
C6—C7	1.382 (2)	C16—H16C	0.9600
C4—Cl—O2^i	168.98 (6)	C14—C9—C8	121.88 (15)
O2—S—C1	107.41 (8)	C10—C9—C8	119.66 (15)
O2—S—C15	106.84 (8)	C11—C10—C9	120.48 (17)
C1—S—C15	97.19 (8)	C11—C10—H10	119.8
C7—O1—C8	106.92 (12)	C9—C10—H10	119.8
C8—C1—C2	107.26 (14)	C12—C11—C10	118.76 (16)
C8—C1—S	128.13 (13)	C12—C11—H11	120.6
C2—C1—S	124.54 (12)	C10—C11—H11	120.6
C7—C2—C3	119.43 (15)	F—C12—C13	118.64 (17)
C7—C2—C1	105.04 (14)	F—C12—C11	118.45 (17)
C3—C2—C1	135.52 (16)	C13—C12—C11	122.91 (16)
C4—C3—C2	116.69 (15)	C12—C13—C14	118.13 (17)
C4—C3—H3	121.7	C12—C13—H13	120.9
C2—C3—H3	121.7	C14—C13—H13	120.9
C3—C4—C5	123.17 (16)	C13—C14—C9	121.24 (16)
C3—C4—Cl	118.61 (14)	C13—C14—H14	119.4
C5—C4—Cl	118.21 (13)	C9—C14—H14	119.4
C6—C5—C4	120.24 (16)	C16—C15—S	111.69 (12)
C6—C5—H5	119.9	C16—C15—H15A	109.3
C4—C5—H5	119.9	S—C15—H15A	109.3
C7—C6—C5	116.50 (16)	C16—C15—H15B	109.3
C7—C6—H6	121.7	S—C15—H15B	109.3
C5—C6—H6	121.7	H15A—C15—H15B	107.9
O1—C7—C6	125.40 (15)	C15—C16—H16A	109.5
O1—C7—C2	110.66 (14)	C15—C16—H16B	109.5
C6—C7—C2	123.94 (15)	H16A—C16—H16B	109.5
C1—C8—O1	110.11 (14)	C15—C16—H16C	109.5
C1—C8—C9	135.48 (15)	H16A—C16—H16C	109.5
O1—C8—C9	114.40 (13)	H16B—C16—H16C	109.5
C14—C9—C10	118.46 (15)
O2—S—C1—C8	143.68 (15)	C2—C1—C8—O1	−0.18 (18)
C15—S—C1—C8	−106.11 (16)	S—C1—C8—O1	−177.16 (11)
O2—S—C1—C2	−32.81 (16)	C2—C1—C8—C9	−178.51 (17)
C15—S—C1—C2	77.40 (15)	S—C1—C8—C9	4.5 (3)
C8—C1—C2—C7	−0.29 (17)	C7—O1—C8—C1	0.59 (17)
S—C1—C2—C7	176.82 (12)	C7—O1—C8—C9	179.30 (13)
C8—C1—C2—C3	179.92 (18)	C1—C8—C9—C14	6.7 (3)
S—C1—C2—C3	−3.0 (3)	O1—C8—C9—C14	−171.53 (14)
C7—C2—C3—C4	0.2 (2)	C1—C8—C9—C10	−173.73 (18)
C1—C2—C3—C4	179.97 (17)	O1—C8—C9—C10	8.0 (2)
C2—C3—C4—C5	−1.2 (2)	C14—C9—C10—C11	1.4 (2)
C2—C3—C4—Cl	179.67 (12)	C8—C9—C10—C11	−178.16 (15)
C3—C4—C5—C6	1.2 (3)	C9—C10—C11—C12	−1.6 (3)
Cl—C4—C5—C6	−179.67 (13)	C10—C11—C12—F	179.52 (16)
C4—C5—C6—C7	−0.1 (3)	C10—C11—C12—C13	0.4 (3)
C8—O1—C7—C6	178.85 (15)	F—C12—C13—C14	−178.07 (16)
C8—O1—C7—C2	−0.78 (17)	C11—C12—C13—C14	1.1 (3)
C5—C6—C7—O1	179.54 (15)	C12—C13—C14—C9	−1.3 (3)
C5—C6—C7—C2	−0.9 (3)	C10—C9—C14—C13	0.1 (3)
C3—C2—C7—O1	−179.50 (13)	C8—C9—C14—C13	179.63 (16)
C1—C2—C7—O1	0.67 (17)	O2—S—C15—C16	−175.89 (12)
C3—C2—C7—C6	0.9 (2)	C1—S—C15—C16	73.42 (13)
C1—C2—C7—C6	−178.98 (15)

Symmetry code: (i) −x+1, −y+1, −z.