2-(5,7-Dimethyl-3-methyl­sulfanyl-1-benzofuran-2-yl)acetic acid

Choi, H.D.; Seo, P.J.; Son, B.W.; Lee, U.

doi:10.1107/S1600536808022988

organic compounds

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Volume 64| Part 8| August 2008| Page o1598

doi:10.1107/S1600536808022988

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2-(5,7-Dimethyl-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid

Hong Dae Choi,^a Pil Ja Seo,^a Byeng Wha Son ^b and Uk Lee ^b ^*

^aDepartment of Chemistry, Dongeui University, San 24 Kaya-dong, Busanjin-gu, Busan 614-714, Republic of Korea, and ^bDepartment of Chemistry, Pukyong National University, 599-1 Daeyeon 3-dong, Nam-gu, Busan 608-737, Republic of Korea
^*Correspondence e-mail: uklee@pknu.ac.kr

(Received 14 July 2008; accepted 22 July 2008; online 26 July 2008)

The title compound, C₁₃H₁₄O₃S, was prepared by alkaline hydrolysis of ethyl 2-(5,7-dimethyl-3-methylsulfanyl-1-benzofuran-2-yl)acetate. In the crystal structure, the carboxyl groups are involved in intermolecular O—H⋯O hydrogen bonds, which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along the a axis by weak C—H⋯π interactions.

Related literature

For the crystal structures of similar 2-(3-methylsulfanyl-1-benzofuran-2-yl)acetic acid derivatives, see: Choi et al. (2007 ); Seo et al. (2007 ).

Experimental

Crystal data

C₁₃H₁₄O₃S
M_r = 250.30
Triclinic, $[P \overline 1]$
a = 4.7225 (9) Å
b = 7.476 (2) Å
c = 17.687 (3) Å
α = 80.91 (3)°
β = 89.86 (3)°
γ = 80.67 (3)°
V = 608.3 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.26 mm⁻¹
T = 293 (2) K
0.40 × 0.40 × 0.20 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: none
4707 measured reflections
2344 independent reflections
2156 reflections with I > 2σ(I)
R_int = 0.059

Refinement

R[F² > 2σ(F²)] = 0.047
wR(F²) = 0.144
S = 1.24
2344 reflections
161 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.41 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

Cg is the centroid of the C2–C7 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3O⋯O2ⁱ	0.73 (4)	1.95 (4)	2.680 (3)	177 (4)
C9—H9A⋯Cgⁱⁱ	0.96	2.72	3.621 (4)	156
Symmetry codes: (i) -x+1, -y+2, -z+1; (ii) x+1, y, z.

Data collection: SMART (Bruker, 2001 ); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; 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.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808022988/cv2433sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808022988/cv2433Isup2.hkl

checkCIF report

Comment top

As a part of our ongoing studies on the synthesis and structures of 2-(3-methylsulfanyl-1-benzofuran-2-yl)acetic acid derivatives, we have described 2-(5-ethyl-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid (Seo et al., 2007) and 2-(3-methylsulfanyl-5-phenyl-1-benzofuran-2-yl)acetic acid (Choi et al., 2007). Here we report the crystal structure of the title compound, (I) (Fig. 1).

In (I), the benzofuran unit is essentially planar, with a mean deviation of 0.004 (2) Å from the least-squares plane defined by the nine constituent atoms. The crystal packing (Fig. 2) is stabilized by classical inversion-related O—H···O hydrogen bonds (Table 1) and C—H···π interactions between a methyl H atom and the ring C2–C7 (Cg is its centroid) of a neighbouring molecule (Table 1).

Related literature top

For the crystal structures of similar 2-(3-methylsulfanyl-1-benzofuran-2-yl) acetic acid derivatives, see: Choi et al. (2007); Seo et al. (2007).

Experimental top

Ethyl 2-(5,7-dimethyl-3-methylsulfanyl-1-benzofuran-2-yl)acetate (417 mg, 1.50 mmol) was added to a solution of potassium hydroxide (505 mg, 9.0 mmol) in water (25 ml) and methanol (25 ml), and the mixture was refluxed for 5 h, then cooled. Water was added, and the solution was extracted with dichloromethane. The aqueous layer was acidified to pH 1 with concentrated hydrochloric acid and then extracted with chloroform, dried over magnesium sulfate, filtered and concentrated under vacuum. The residue was purified by column chromatography (ethyl acetate) to afford the title compound as a colorless solid [yield 82%, m.p. 420–421 K; R_f = 0.66 (ethyl acetate)]. Single crystals suitable for X-ray diffraction were prepared by evaporation of a solution of the title compound in benzene at room temperature. Spectroscopic analysis: ¹H NMR (CDCl₃, 400 MHz) δ 2.32 (s, 3H), 2.43 (s, 3H), 2.45 (s, 3H), 4.03 (s, 2H), 6.93 (s, 1H), 7.25 (s, 1H), 10.10 (s, 1H); EI—MS 250 [M⁺].

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); 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 top

	Fig. 1. The molecular structure of the title compound, showing displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. A portion of the crystal packing showing C—H···π interaction and hydrogen bonds (dotted lines). Cg denotes the C2–C7 ring centroid [symmetry codes: (i) x + 1, y, z; (ii) -x + 1, -y + 2, -z + 1; (iii) x - 1, y, z].

2-(5,7-Dimethyl-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid top

Crystal data top

C₁₃H₁₄O₃S	Z = 2
M_r = 250.30	F(000) = 264
Triclinic, P1	D_x = 1.367 Mg m⁻³
Hall symbol: -P_1	Melting point = 420–421 K
a = 4.7225 (9) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.476 (2) Å	Cell parameters from 3835 reflections
c = 17.687 (3) Å	θ = 2.3–28.3°
α = 80.91 (3)°	µ = 0.26 mm⁻¹
β = 89.86 (3)°	T = 293 K
γ = 80.67 (3)°	Block, colourless
V = 608.3 (2) Å³	0.40 × 0.40 × 0.20 mm

Data collection top

Bruker SMART CCD diffractometer	2156 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.059
Graphite monochromator	θ_max = 26.0°, θ_min = 1.2°
Detector resolution: 10.0 pixels mm^-1	h = −5→5
ϕ and ω scans	k = −9→9
4707 measured reflections	l = −21→21
2344 independent 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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.144	H atoms treated by a mixture of independent and constrained refinement
S = 1.24	w = 1/[σ²(F_o²) + (0.063P)² + 0.3562P] where P = (F_o² + 2F_c²)/3
2344 reflections	(Δ/σ)_max < 0.001
161 parameters	Δρ_max = 0.38 e Å⁻³
0 restraints	Δρ_min = −0.41 e Å⁻³

Crystal data top

C₁₃H₁₄O₃S	γ = 80.67 (3)°
M_r = 250.30	V = 608.3 (2) Å³
Triclinic, P1	Z = 2
a = 4.7225 (9) Å	Mo Kα radiation
b = 7.476 (2) Å	µ = 0.26 mm⁻¹
c = 17.687 (3) Å	T = 293 K
α = 80.91 (3)°	0.40 × 0.40 × 0.20 mm
β = 89.86 (3)°

Data collection top

Bruker SMART CCD diffractometer	2156 reflections with I > 2σ(I)
4707 measured reflections	R_int = 0.059
2344 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.047	0 restraints
wR(F²) = 0.144	H atoms treated by a mixture of independent and constrained refinement
S = 1.24	Δρ_max = 0.38 e Å⁻³
2344 reflections	Δρ_min = −0.41 e Å⁻³
161 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
S	0.85977 (13)	0.34264 (8)	0.36615 (3)	0.0254 (2)
O1	0.4166 (3)	0.8236 (2)	0.27417 (9)	0.0223 (4)
O2	0.2357 (4)	0.9616 (2)	0.44893 (10)	0.0272 (4)
O3	0.6544 (4)	0.7728 (2)	0.47532 (11)	0.0282 (4)
H3O	0.685 (8)	0.848 (5)	0.494 (2)	0.049 (11)*
C1	0.6982 (5)	0.5473 (3)	0.30908 (14)	0.0214 (5)
C2	0.7803 (5)	0.6242 (3)	0.23378 (14)	0.0232 (5)
C3	0.9867 (5)	0.5690 (3)	0.18203 (15)	0.0268 (5)
H3	1.1098	0.4574	0.1936	0.032*
C4	1.0055 (6)	0.6834 (4)	0.11284 (15)	0.0293 (6)
C5	0.8179 (6)	0.8526 (3)	0.09713 (15)	0.0306 (6)
H5	0.8332	0.9275	0.0505	0.037*
C6	0.6115 (6)	0.9133 (3)	0.14758 (15)	0.0279 (5)
C7	0.6010 (5)	0.7931 (3)	0.21521 (14)	0.0231 (5)
C8	0.4821 (5)	0.6706 (3)	0.32972 (13)	0.0211 (5)
C9	1.2248 (6)	0.6283 (4)	0.05502 (17)	0.0400 (7)
H9A	1.4113	0.6436	0.0718	0.060*
H9B	1.1762	0.7043	0.0063	0.060*
H9C	1.2265	0.5021	0.0502	0.060*
C10	0.4134 (6)	1.0944 (3)	0.13076 (17)	0.0359 (6)
H10A	0.2325	1.0833	0.1544	0.054*
H10B	0.3842	1.1291	0.0764	0.054*
H10C	0.4972	1.1864	0.1508	0.054*
C11	0.3130 (5)	0.6760 (3)	0.40038 (13)	0.0225 (5)
H11A	0.3482	0.5562	0.4324	0.027*
H11B	0.1099	0.7050	0.3869	0.027*
C12	0.3944 (5)	0.8187 (3)	0.44444 (13)	0.0195 (5)
C13	0.7336 (6)	0.1752 (3)	0.31692 (18)	0.0360 (6)
H13A	0.5277	0.1920	0.3176	0.054*
H13B	0.8110	0.0538	0.3421	0.054*
H13C	0.7950	0.1908	0.2649	0.054*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S	0.0300 (3)	0.0185 (3)	0.0271 (3)	−0.0028 (2)	−0.0065 (2)	−0.0025 (2)
O1	0.0275 (8)	0.0163 (7)	0.0230 (9)	−0.0025 (6)	0.0001 (6)	−0.0039 (6)
O2	0.0275 (9)	0.0214 (8)	0.0334 (10)	−0.0003 (7)	−0.0053 (7)	−0.0105 (7)
O3	0.0251 (9)	0.0248 (9)	0.0370 (10)	−0.0017 (7)	−0.0069 (7)	−0.0140 (8)
C1	0.0254 (11)	0.0162 (10)	0.0241 (12)	−0.0044 (8)	−0.0027 (9)	−0.0063 (9)
C2	0.0256 (12)	0.0200 (11)	0.0263 (12)	−0.0079 (9)	−0.0025 (9)	−0.0066 (9)
C3	0.0267 (12)	0.0261 (12)	0.0297 (13)	−0.0068 (9)	0.0006 (10)	−0.0084 (10)
C4	0.0334 (13)	0.0314 (13)	0.0289 (13)	−0.0150 (10)	0.0057 (10)	−0.0125 (10)
C5	0.0418 (15)	0.0292 (13)	0.0235 (13)	−0.0155 (11)	0.0006 (10)	−0.0024 (10)
C6	0.0366 (13)	0.0209 (11)	0.0281 (13)	−0.0092 (10)	−0.0021 (10)	−0.0051 (10)
C7	0.0280 (12)	0.0209 (11)	0.0227 (12)	−0.0074 (9)	−0.0006 (9)	−0.0066 (9)
C8	0.0256 (11)	0.0170 (10)	0.0223 (11)	−0.0066 (8)	−0.0045 (9)	−0.0045 (9)
C9	0.0449 (16)	0.0437 (16)	0.0368 (15)	−0.0173 (13)	0.0140 (13)	−0.0125 (13)
C10	0.0480 (16)	0.0247 (13)	0.0318 (14)	−0.0035 (11)	−0.0049 (12)	0.0031 (11)
C11	0.0252 (11)	0.0191 (10)	0.0253 (12)	−0.0074 (9)	0.0000 (9)	−0.0059 (9)
C12	0.0218 (11)	0.0188 (10)	0.0193 (11)	−0.0071 (8)	0.0025 (8)	−0.0035 (8)
C13	0.0439 (15)	0.0200 (11)	0.0452 (16)	−0.0068 (11)	−0.0132 (12)	−0.0066 (11)

Geometric parameters (Å, º) top

S—C1	1.755 (2)	C5—H5	0.9300
S—C13	1.808 (3)	C6—C7	1.384 (4)
O1—C8	1.379 (3)	C6—C10	1.503 (4)
O1—C7	1.380 (3)	C8—C11	1.484 (3)
O2—C12	1.215 (3)	C9—H9A	0.9600
O3—C12	1.316 (3)	C9—H9B	0.9600
O3—H3O	0.73 (4)	C9—H9C	0.9600
C1—C8	1.351 (3)	C10—H10A	0.9600
C1—C2	1.443 (3)	C10—H10B	0.9600
C2—C7	1.393 (3)	C10—H10C	0.9600
C2—C3	1.394 (3)	C11—C12	1.514 (3)
C3—C4	1.389 (4)	C11—H11A	0.9700
C3—H3	0.9300	C11—H11B	0.9700
C4—C5	1.410 (4)	C13—H13A	0.9600
C4—C9	1.509 (4)	C13—H13B	0.9600
C5—C6	1.390 (4)	C13—H13C	0.9600

C1—S—C13	100.58 (12)	C4—C9—H9A	109.5
C8—O1—C7	105.62 (18)	C4—C9—H9B	109.5
C12—O3—H3O	109 (3)	H9A—C9—H9B	109.5
C8—C1—C2	106.3 (2)	C4—C9—H9C	109.5
C8—C1—S	126.10 (19)	H9A—C9—H9C	109.5
C2—C1—S	127.50 (18)	H9B—C9—H9C	109.5
C7—C2—C3	119.3 (2)	C6—C10—H10A	109.5
C7—C2—C1	105.7 (2)	C6—C10—H10B	109.5
C3—C2—C1	135.1 (2)	H10A—C10—H10B	109.5
C4—C3—C2	118.9 (2)	C6—C10—H10C	109.5
C4—C3—H3	120.6	H10A—C10—H10C	109.5
C2—C3—H3	120.6	H10B—C10—H10C	109.5
C3—C4—C5	119.3 (2)	C8—C11—C12	110.56 (18)
C3—C4—C9	120.6 (3)	C8—C11—H11A	109.5
C5—C4—C9	120.1 (2)	C12—C11—H11A	109.5
C6—C5—C4	123.5 (2)	C8—C11—H11B	109.5
C6—C5—H5	118.3	C12—C11—H11B	109.5
C4—C5—H5	118.3	H11A—C11—H11B	108.1
C7—C6—C5	114.6 (2)	O2—C12—O3	124.3 (2)
C7—C6—C10	122.1 (2)	O2—C12—C11	122.7 (2)
C5—C6—C10	123.3 (2)	O3—C12—C11	112.94 (19)
O1—C7—C6	125.3 (2)	S—C13—H13A	109.5
O1—C7—C2	110.3 (2)	S—C13—H13B	109.5
C6—C7—C2	124.4 (2)	H13A—C13—H13B	109.5
C1—C8—O1	112.1 (2)	S—C13—H13C	109.5
C1—C8—C11	132.8 (2)	H13A—C13—H13C	109.5
O1—C8—C11	115.00 (19)	H13B—C13—H13C	109.5

C13—S—C1—C8	110.5 (2)	C10—C6—C7—O1	−0.8 (4)
C13—S—C1—C2	−74.3 (2)	C5—C6—C7—C2	0.5 (3)
C8—C1—C2—C7	0.2 (2)	C10—C6—C7—C2	−179.7 (2)
S—C1—C2—C7	−175.77 (17)	C3—C2—C7—O1	−178.87 (19)
C8—C1—C2—C3	179.0 (2)	C1—C2—C7—O1	0.2 (2)
S—C1—C2—C3	3.0 (4)	C3—C2—C7—C6	0.1 (3)
C7—C2—C3—C4	−0.7 (3)	C1—C2—C7—C6	179.1 (2)
C1—C2—C3—C4	−179.4 (2)	C2—C1—C8—O1	−0.5 (2)
C2—C3—C4—C5	0.6 (3)	S—C1—C8—O1	175.57 (15)
C2—C3—C4—C9	−179.7 (2)	C2—C1—C8—C11	−177.8 (2)
C3—C4—C5—C6	0.0 (4)	S—C1—C8—C11	−1.8 (4)
C9—C4—C5—C6	−179.6 (2)	C7—O1—C8—C1	0.5 (2)
C4—C5—C6—C7	−0.6 (4)	C7—O1—C8—C11	178.39 (17)
C4—C5—C6—C10	179.6 (2)	C1—C8—C11—C12	108.4 (3)
C8—O1—C7—C6	−179.4 (2)	O1—C8—C11—C12	−68.9 (2)
C8—O1—C7—C2	−0.4 (2)	C8—C11—C12—O2	109.1 (2)
C5—C6—C7—O1	179.4 (2)	C8—C11—C12—O3	−69.6 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3O···O2ⁱ	0.73 (4)	1.95 (4)	2.680 (3)	177 (4)
C9—H9A···Cgⁱⁱ	0.96	2.72	3.621 (4)	156

Symmetry codes: (i) −x+1, −y+2, −z+1; (ii) x+1, y, z.

Experimental details

Crystal data
Chemical formula	C₁₃H₁₄O₃S
M_r	250.30
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	4.7225 (9), 7.476 (2), 17.687 (3)
α, β, γ (°)	80.91 (3), 89.86 (3), 80.67 (3)
V (Å³)	608.3 (2)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.26
Crystal size (mm)	0.40 × 0.40 × 0.20

Data collection
Diffractometer	Bruker SMART CCD diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	4707, 2344, 2156
R_int	0.059
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.144, 1.24
No. of reflections	2344
No. of parameters	161
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.38, −0.41

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3O···O2ⁱ	0.73 (4)	1.95 (4)	2.680 (3)	177 (4)
C9—H9A···Cgⁱⁱ	0.96	2.72	3.621 (4)	156.4

Symmetry codes: (i) −x+1, −y+2, −z+1; (ii) x+1, y, z.

References

Brandenburg, K. (1998). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2001). SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Choi, H. D., Seo, P. J., Son, B. W. & Lee, U. (2007). Acta Cryst. E63, o3468. Web of Science CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Seo, P. J., Choi, H. D., Son, B. W. & Lee, U. (2007). Acta Cryst. E63, o2048–o2049. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar

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doi:10.1107/S1600536808022988

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