5-Methyl-3-methyl­sulfinyl-2-phenyl-1-benzofuran

The title compound, C₁₆H₁₄O₂S, was prepared by the oxidation of 3,5-dimethyl-2-phenyl-1-benzofuran using 3-chloro­perbenzoic acid. The O atom and the methyl group of the methyl­sulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. The phenyl ring is rotated out of the benzofuran plane, with a dihedral angle of 31.94 (7)°. The crystal packing is stabilized by C—H...π(phenyl ring) inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.040
• wR factor = 0.114
• Data-to-parameter ratio = 15.4

checkCIF/PLATON results

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Alert level C
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)        200 Deg.
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for          S
PLAT717_ALERT_1_C D...A   Unknown or Inconsistent Label ..........    CG(PHEN

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

   2 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
   0 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

1-Benzofuran ring systems have attracted considerable interest because of their various pharmacological properties (Howlett et al., 1999; Ward, 1997). With our continuing studies on the synthesis and structures of 2-phenyl-benzofuran derivatives, the crystal structures of 5-chloro-3-methylsulfinyl-2-phenyl-1-benzofuran (Choi et al., 2007a) and 5-bromo-3-methylsulfinyl-2-phenyl-1-benzofuran (Choi et al., 2007b) have been described to the literature. Herein we report the molecular and crystal structure of the title compound (I) (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.016 Å from the least-squares plane defined by the nine constituent atoms. The dihedral angle in (I) formed by the plane of the benzofuran ring and the plane of phenyl ring is 31.94 (7)°. The molecular packing (Fig. 2) is stabilized by CH₂—H···π interactions between the S-methyl group and a phenyl ring, with a C16—H16B···Cgⁱ separation of 3.14 Å (Cg is a centroid of the C9—C14 phenyl ring, symmetry code as in Fig. 2).

Related literature

For the crystal structures of isomers of the title compound, see: Choi et al. (2007a,b). For details of the pharmacological properties of benzofuran compounds, see: Howlett et al. (1999) and Ward (1997).

S2. Experimental

3-Chloroperbenzoic acid (77%, 471 mg, 2.1 mmol) was added in small portions to a stirred solution of 3,5-dimethyl-2-phenyl-1-benzofuran (508 mg, 2.0 mmol) in dichloromethane (30 ml) at 273 K. After being stirred at room temperature for 1 h, the mixture was washed with saturated sodium bicarbonate solution and the organic layer separated, dried over magnesium sulfate, filtered and concentrated in vacuum. The residue was purified by column chromatography (ethyl acetate) to afford the title compound as a colorless solid [yield 83%, m.p. 417–418 K; R_f = 0.56 (ethyl acetate)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a dilute solution of title compound (I) in tetrahydrofuran at room temperature.

S3. Refinement

All H atoms were geometrically located in ideal positions and refined using a riding model, with C—H = 0.93 Å for aromatic H atoms and C—H = 0.96 Å for methyl H atoms, and with U_iso(H) = 1.2U_eq(C) for aromatic H atoms, and U_iso(H) = 1.5U_eq(C) for methyl H atoms.

Computing details

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

Figures

	Fig. 1. The molecular structure of (I), showing displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. CH2—H···π interactions in (I). Cg denotes ring centroid. [Symmetry codes: (i) 1 + x, y, z; (ii) x - 1, y, z.]

5-Methyl-3-methylsulfinyl-2-phenyl-1-benzofuran

Crystal data

C16H14O2S	Z = 2
Mr = 270.33	F(000) = 284
Triclinic, P1	Dx = 1.301 Mg m^−3
Hall symbol: -p_1	Mo Kα radiation, λ = 0.71073 Å
a = 5.3788 (5) Å	Cell parameters from 2704 reflections
b = 8.7492 (8) Å	θ = 2.4–28.2°
c = 15.120 (1) Å	µ = 0.23 mm^−1
α = 78.140 (2)°	T = 298 K
β = 85.231 (2)°	Block, colourless
γ = 83.248 (2)°	0.52 × 0.41 × 0.23 mm
V = 690.26 (10) Å^3

Data collection

Bruker SMART CCD diffractometer	2308 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.026
Graphite monochromator	θmax = 26.0°, θmin = 2.4°
Detector resolution: 10.00 pixels mm^-1	h = −6→6
φ and ω scans	k = −10→9
3934 measured reflections	l = −17→18
2673 independent 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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.114	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0633P)^2 + 0.1495P] where P = (Fo^2 + 2Fc^2)/3
2673 reflections	(Δ/σ)max < 0.001
174 parameters	Δρmax = 0.25 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > σ(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	−0.01847 (8)	0.17113 (5)	0.39289 (3)	0.04671 (17)
O1	−0.0475 (2)	0.41996 (15)	0.14345 (9)	0.0543 (3)
O2	−0.0081 (3)	0.00196 (16)	0.39122 (10)	0.0737 (5)
C1	0.0325 (3)	0.2664 (2)	0.27927 (12)	0.0437 (4)
C2	0.2146 (3)	0.2144 (2)	0.21257 (11)	0.0442 (4)
C3	0.4194 (3)	0.1002 (2)	0.21359 (13)	0.0490 (4)
H3	0.4613	0.0326	0.2674	0.059*
C4	0.5596 (3)	0.0887 (2)	0.13358 (13)	0.0539 (5)
C5	0.4902 (4)	0.1901 (3)	0.05283 (14)	0.0652 (6)
H5	0.5848	0.1812	−0.0006	0.078*
C6	0.2868 (4)	0.3026 (3)	0.04971 (13)	0.0647 (6)
H6	0.2412	0.3685	−0.0042	0.078*
C7	0.1552 (3)	0.3118 (2)	0.13069 (12)	0.0502 (4)
C8	−0.1166 (3)	0.3897 (2)	0.23446 (12)	0.0472 (4)
C9	−0.3267 (3)	0.4955 (2)	0.26260 (13)	0.0494 (4)
C10	−0.3412 (4)	0.5378 (3)	0.34680 (16)	0.0616 (5)
H10	−0.2165	0.4981	0.3869	0.074*
C11	−0.5421 (4)	0.6394 (3)	0.37099 (18)	0.0740 (7)
H11	−0.5535	0.6656	0.4279	0.089*
C12	−0.7245 (4)	0.7014 (3)	0.3110 (2)	0.0752 (7)
H12	−0.8571	0.7707	0.3271	0.090*
C13	−0.7103 (4)	0.6609 (3)	0.22781 (18)	0.0705 (6)
H13	−0.8349	0.7018	0.1878	0.085*
C14	−0.5121 (3)	0.5594 (2)	0.20282 (15)	0.0575 (5)
H14	−0.5028	0.5339	0.1458	0.069*
C15	0.7849 (4)	−0.0321 (3)	0.13411 (17)	0.0691 (6)
H15A	0.8440	−0.0616	0.1940	0.104*
H15B	0.9155	0.0116	0.0928	0.104*
H15C	0.7382	−0.1231	0.1158	0.104*
C16	0.2699 (4)	0.2019 (3)	0.43396 (15)	0.0777 (7)
H16A	0.2749	0.1545	0.4970	0.117*
H16B	0.2818	0.3126	0.4262	0.117*
H16C	0.4079	0.1553	0.4007	0.117*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S	0.0475 (3)	0.0457 (3)	0.0452 (3)	−0.00823 (18)	0.00619 (18)	−0.00651 (18)
O1	0.0574 (8)	0.0514 (7)	0.0472 (7)	0.0105 (6)	−0.0044 (6)	−0.0024 (6)
O2	0.1148 (13)	0.0462 (8)	0.0576 (9)	−0.0207 (8)	0.0182 (8)	−0.0072 (6)
C1	0.0433 (9)	0.0421 (9)	0.0440 (9)	−0.0032 (7)	−0.0001 (7)	−0.0064 (7)
C2	0.0460 (9)	0.0417 (9)	0.0436 (9)	−0.0033 (7)	−0.0012 (7)	−0.0065 (7)
C3	0.0483 (10)	0.0440 (9)	0.0519 (10)	0.0002 (7)	−0.0046 (8)	−0.0053 (8)
C4	0.0493 (10)	0.0529 (11)	0.0593 (11)	0.0006 (8)	−0.0006 (8)	−0.0148 (9)
C5	0.0680 (13)	0.0746 (14)	0.0498 (11)	0.0048 (10)	0.0072 (9)	−0.0162 (10)
C6	0.0766 (14)	0.0673 (13)	0.0431 (10)	0.0089 (10)	−0.0031 (9)	−0.0040 (9)
C7	0.0515 (10)	0.0479 (10)	0.0477 (10)	0.0057 (8)	−0.0044 (8)	−0.0071 (8)
C8	0.0472 (9)	0.0441 (9)	0.0485 (10)	−0.0026 (7)	−0.0015 (7)	−0.0072 (7)
C9	0.0445 (9)	0.0388 (9)	0.0631 (11)	−0.0032 (7)	0.0017 (8)	−0.0085 (8)
C10	0.0588 (12)	0.0562 (11)	0.0717 (13)	−0.0003 (9)	−0.0027 (9)	−0.0207 (10)
C11	0.0749 (15)	0.0616 (13)	0.0912 (17)	−0.0074 (11)	0.0137 (13)	−0.0356 (13)
C12	0.0557 (12)	0.0493 (12)	0.119 (2)	0.0022 (9)	0.0129 (13)	−0.0245 (13)
C13	0.0519 (11)	0.0546 (12)	0.0989 (18)	0.0056 (9)	−0.0028 (11)	−0.0080 (12)
C14	0.0477 (10)	0.0495 (10)	0.0716 (13)	−0.0007 (8)	−0.0020 (9)	−0.0067 (9)
C15	0.0563 (12)	0.0690 (14)	0.0811 (15)	0.0095 (10)	0.0013 (10)	−0.0240 (11)
C16	0.0682 (14)	0.1050 (19)	0.0569 (13)	−0.0326 (13)	−0.0148 (10)	0.0087 (12)

Geometric parameters (Å, º)

S—O2	1.4799 (14)	C9—C10	1.391 (3)
S—C1	1.7630 (17)	C9—C14	1.391 (3)
S—C16	1.787 (2)	C10—C11	1.391 (3)
O1—C8	1.375 (2)	C10—H10	0.9300
O1—C7	1.385 (2)	C11—C12	1.378 (3)
C1—C8	1.361 (2)	C11—H11	0.9300
C1—C2	1.450 (2)	C12—C13	1.370 (4)
C2—C7	1.389 (2)	C12—H12	0.9300
C2—C3	1.396 (2)	C13—C14	1.384 (3)
C3—C4	1.387 (3)	C13—H13	0.9300
C3—H3	0.9300	C14—H14	0.9300
C4—C5	1.404 (3)	C15—H15A	0.9600
C4—C15	1.511 (3)	C15—H15B	0.9600
C5—C6	1.380 (3)	C15—H15C	0.9600
C5—H5	0.9300	C16—H16A	0.9600
C6—C7	1.375 (3)	C16—H16B	0.9600
C6—H6	0.9300	C16—H16C	0.9600
C8—C9	1.467 (2)
O2—S—C1	105.74 (8)	C10—C9—C8	121.54 (17)
O2—S—C16	107.32 (12)	C14—C9—C8	119.48 (18)
C1—S—C16	98.26 (9)	C9—C10—C11	120.0 (2)
C8—O1—C7	106.44 (13)	C9—C10—H10	120.0
C8—C1—C2	106.90 (15)	C11—C10—H10	120.0
C8—C1—S	125.75 (14)	C12—C11—C10	120.3 (2)
C2—C1—S	126.70 (13)	C12—C11—H11	119.9
C7—C2—C3	118.70 (16)	C10—C11—H11	119.9
C7—C2—C1	105.21 (15)	C13—C12—C11	119.9 (2)
C3—C2—C1	136.07 (16)	C13—C12—H12	120.0
C4—C3—C2	119.38 (17)	C11—C12—H12	120.0
C4—C3—H3	120.3	C12—C13—C14	120.5 (2)
C2—C3—H3	120.3	C12—C13—H13	119.8
C3—C4—C5	119.35 (18)	C14—C13—H13	119.8
C3—C4—C15	119.91 (18)	C13—C14—C9	120.3 (2)
C5—C4—C15	120.75 (18)	C13—C14—H14	119.8
C6—C5—C4	122.46 (19)	C9—C14—H14	119.8
C6—C5—H5	118.8	C4—C15—H15A	109.5
C4—C5—H5	118.8	C4—C15—H15B	109.5
C7—C6—C5	116.35 (18)	H15A—C15—H15B	109.5
C7—C6—H6	121.8	C4—C15—H15C	109.5
C5—C6—H6	121.8	H15A—C15—H15C	109.5
C6—C7—O1	125.81 (17)	H15B—C15—H15C	109.5
C6—C7—C2	123.75 (18)	S—C16—H16A	109.5
O1—C7—C2	110.42 (16)	S—C16—H16B	109.5
C1—C8—O1	111.02 (15)	H16A—C16—H16B	109.5
C1—C8—C9	134.00 (17)	S—C16—H16C	109.5
O1—C8—C9	114.97 (15)	H16A—C16—H16C	109.5
C10—C9—C14	118.95 (18)	H16B—C16—H16C	109.5
O2—S—C1—C8	127.57 (17)	C3—C2—C7—O1	−178.22 (15)
C16—S—C1—C8	−121.74 (18)	C1—C2—C7—O1	0.7 (2)
O2—S—C1—C2	−42.01 (18)	C2—C1—C8—O1	1.0 (2)
C16—S—C1—C2	68.69 (19)	S—C1—C8—O1	−170.29 (12)
C8—C1—C2—C7	−1.0 (2)	C2—C1—C8—C9	−177.78 (19)
S—C1—C2—C7	170.14 (14)	S—C1—C8—C9	10.9 (3)
C8—C1—C2—C3	177.6 (2)	C7—O1—C8—C1	−0.5 (2)
S—C1—C2—C3	−11.2 (3)	C7—O1—C8—C9	178.49 (15)
C7—C2—C3—C4	1.0 (3)	C1—C8—C9—C10	32.1 (3)
C1—C2—C3—C4	−177.57 (19)	O1—C8—C9—C10	−146.66 (18)
C2—C3—C4—C5	−1.2 (3)	C1—C8—C9—C14	−150.1 (2)
C2—C3—C4—C15	178.73 (17)	O1—C8—C9—C14	31.2 (2)
C3—C4—C5—C6	0.3 (3)	C14—C9—C10—C11	1.6 (3)
C15—C4—C5—C6	−179.6 (2)	C8—C9—C10—C11	179.47 (19)
C4—C5—C6—C7	0.7 (4)	C9—C10—C11—C12	−1.5 (3)
C5—C6—C7—O1	177.1 (2)	C10—C11—C12—C13	1.1 (4)
C5—C6—C7—C2	−0.9 (3)	C11—C12—C13—C14	−0.8 (4)
C8—O1—C7—C6	−178.4 (2)	C12—C13—C14—C9	1.0 (3)
C8—O1—C7—C2	−0.2 (2)	C10—C9—C14—C13	−1.4 (3)
C3—C2—C7—C6	0.1 (3)	C8—C9—C14—C13	−179.28 (18)
C1—C2—C7—C6	179.04 (19)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C16—H16B···Cg(phenyl)^i	0.96	3.14	3.941 (2)	142

Symmetry code: (i) x+1, y, z.