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ISSN: 2056-9890

2-(6,7-Di­methyl-3-methyl­sulfanyl-1-benzo­furan-2-yl)acetic acid

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 18 July 2008; accepted 30 July 2008; online 6 August 2008)

In the title compound, C13H14O3S, the methyl group of the methyl­sulfanyl substituent is almost perpendicular to the plane of the benzofuran fragment [80.5 (9)°]. The carboxylic acid 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 C—H⋯π inter­actions.

Related literature

For related structures, see: Choi et al. (2007[Choi, H. D., Seo, P. J., Son, B. W. & Lee, U. (2007). Acta Cryst. E63, o3468.]); Seo et al. (2007[Seo, P. J., Choi, H. D., Son, B. W. & Lee, U. (2007). Acta Cryst. E63, o2048-o2049.]).

[Scheme 1]

Experimental

Crystal data
  • C13H14O3S

  • Mr = 250.30

  • Monoclinic, P 21 /c

  • a = 18.050 (2) Å

  • b = 4.9422 (5) Å

  • c = 13.885 (1) Å

  • β = 104.451 (2)°

  • V = 1199.4 (2) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.26 mm−1

  • T = 173 (2) K

  • 0.40 × 0.20 × 0.10 mm

Data collection
  • Bruker SMART CCD diffractometer

  • Absorption correction: none

  • 6673 measured reflections

  • 2595 independent reflections

  • 2269 reflections with I > 2σ(I)

  • Rint = 0.035

Refinement
  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.119

  • S = 1.17

  • 2595 reflections

  • 161 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.42 e Å−3

  • Δρmin = −0.25 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C9—H9ACgi 0.98 2.86 3.617 (2) 135
O2—H2O⋯O3ii 0.83 (3) 1.89 (3) 2.717 (2) 175 (3)
Symmetry codes: (ii) (i) x, y-1, z; -x+1, -y+1, -z+2. Cg is the centroid of the C2–C7 benzene ring.

Data collection: SMART (Bruker, 2001[Bruker (2001). SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2001[Bruker (2001). SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and DIAMOND (Brandenburg, 1998[Brandenburg, K. (1998). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

This work is related to our communications on the synthesis and structure of 2-(3-methylsulfanyl-1-benzofuran-2-yl)acetic acid derivatives, viz. 2-(3-methylsulfanyl-5-phenyl-1-benzofuran-2-yl)acetic acid (Choi et al., 2007) and 2-(5-ethyl-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid (Seo et al., 2007). Here we report the crystal structure of the title compound, (I), 2-(6,7-dimethyl-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid (Fig. 1).

The benzofuran unit is essentially planar, with a mean deviation of 0.003 (1) Å from the least-squares plane defined by the nine constituent atoms. In the crystal structure, the carboxyl groups are involved in intermolecular O—H···O hydrogen bonds (Fig. 2 and Table 1; symmetry code as in Fig. 2), which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along a axis by C—H···π interactions, with a C9—H9A···Cgi separation of 2.86 Å (Fig. 2 and Table 1; Cg is the centroid of the C2—C7 benzene ring, symmetry code as in Fig. 2).

Related literature top

For related structures, see: Choi et al. (2007); Seo et al. (2007). Cg is the centroid of the C2–C7 benzene ring.

Experimental top

Ethyl 2-(6,7-dimethyl-3-methylsulfanyl-1-benzofuran-2-yl)acetate (334 mg, 1.20 mmol) was added to a solution of potassium hydroxide (337 mg, 6.0 mmol) in water (20 ml) and methanol (20 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 84%, m.p. 426–427 K; Rf = 0.63 (ethyl acetate)]. Colorless blocks of (I) were prepared by evaporation of a solution of the title compound in diisopropyl ether at room temperature. Spectroscopic analysis: 1H NMR (CDCl3, 400 MHz) δ 2.32 (s, 3H), 2.38 (s, 3H), 2.40 (s, 3H), 4.04 (s, 2H), 7.10 (d, J = 7.84 Hz, 1H), 7.36 (d, J = 7.84 Hz, 1H), 9.08 (s, 1H); EI—MS 250 [M+].

Refinement top

Atom H3O of the hydroxy group was found in a difference Fourier map and refined freely. The other H atoms were positioned geometrically and refined using a riding model, with C—H = 0.95 Å for aromatic H atoms, 0.99 Å for methylene H atoms and 0.98 Å for methyl H atoms, respectively, and with Uiso(H) = 1.2Ueq(C) for aromatic and methylene H atoms and 1.5Ueq(C) for methyl H atoms.

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
[Figure 1] Fig. 1. The molecular structure of (I), showing displacement ellipsoids for the non-hydrogen atoms drawn at the 50% probability level.
[Figure 2] Fig. 2. C—H···π interactions and hydrogen bonds (dotted lines) in (I). Cg denotes the ring centroid. [Symmetry code: (i) x, y - 1, z; (ii) -x + 1, -y + 1, -z + 2; (iii) -x + 1, -y, -z + 2; (iv) x, y + 1, z.]
2-(6,7-Dimethyl-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid top
Crystal data top
C13H14O3SF(000) = 528
Mr = 250.30Dx = 1.386 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P_2ybcCell parameters from 4188 reflections
a = 18.050 (2) Åθ = 3.0–28.3°
b = 4.9422 (5) ŵ = 0.26 mm1
c = 13.885 (1) ÅT = 173 K
β = 104.451 (2)°Block, colorless
V = 1199.4 (2) Å30.40 × 0.20 × 0.10 mm
Z = 4
Data collection top
Bruker SMART CCD
diffractometer
2269 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.035
Graphite monochromatorθmax = 27.0°, θmin = 1.2°
Detector resolution: 10.0 pixels mm-1h = 1923
ϕ and ω scansk = 56
6673 measured reflectionsl = 1717
2595 independent reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.038Hydrogen site location: difmap (O-H) and geom (C-H)
wR(F2) = 0.119H atoms treated by a mixture of independent and constrained refinement
S = 1.17 w = 1/[σ2(Fo2) + (0.0641P)2 + 0.395P]
where P = (Fo2 + 2Fc2)/3
2595 reflections(Δ/σ)max < 0.001
161 parametersΔρmax = 0.42 e Å3
0 restraintsΔρmin = 0.25 e Å3
Crystal data top
C13H14O3SV = 1199.4 (2) Å3
Mr = 250.30Z = 4
Monoclinic, P21/cMo Kα radiation
a = 18.050 (2) ŵ = 0.26 mm1
b = 4.9422 (5) ÅT = 173 K
c = 13.885 (1) Å0.40 × 0.20 × 0.10 mm
β = 104.451 (2)°
Data collection top
Bruker SMART CCD
diffractometer
2269 reflections with I > 2σ(I)
6673 measured reflectionsRint = 0.035
2595 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.119H atoms treated by a mixture of independent and constrained refinement
S = 1.17Δρmax = 0.42 e Å3
2595 reflectionsΔρmin = 0.25 e Å3
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
xyzUiso*/Ueq
S0.36076 (2)0.71244 (9)0.66542 (3)0.02429 (16)
O10.22123 (6)0.3898 (3)0.81259 (8)0.0204 (3)
O20.40090 (8)0.3577 (3)0.94500 (11)0.0324 (4)
H2O0.4453 (16)0.310 (6)0.970 (2)0.049 (8)*
O30.45128 (7)0.7710 (3)0.96729 (10)0.0284 (3)
C10.29079 (9)0.5385 (3)0.70833 (12)0.0189 (4)
C20.23677 (9)0.3392 (4)0.65574 (12)0.0189 (4)
C30.21948 (10)0.2279 (4)0.56064 (13)0.0235 (4)
H30.24630.28110.51290.028*
C40.16167 (10)0.0365 (4)0.53846 (13)0.0252 (4)
H40.14900.04180.47390.030*
C50.12090 (10)0.0469 (4)0.60716 (13)0.0229 (4)
C60.13800 (9)0.0629 (4)0.70363 (13)0.0209 (4)
C70.19588 (9)0.2551 (3)0.72277 (12)0.0187 (4)
C80.27891 (9)0.5601 (4)0.80010 (12)0.0192 (4)
C90.05928 (11)0.2584 (4)0.57689 (16)0.0311 (5)
H9A0.07290.41810.61950.047*
H9B0.05430.30970.50740.047*
H9C0.01050.18490.58410.047*
C100.09738 (11)0.0203 (4)0.78102 (15)0.0316 (5)
H10A0.11970.07520.84340.047*
H10B0.10290.21590.79210.047*
H10C0.04300.02560.75810.047*
C110.31794 (10)0.7259 (4)0.88784 (13)0.0221 (4)
H11A0.28650.72550.93700.026*
H11B0.32180.91520.86630.026*
C120.39713 (10)0.6221 (4)0.93705 (12)0.0197 (4)
C130.43420 (11)0.4564 (4)0.68607 (16)0.0315 (4)
H13A0.45290.42300.75760.047*
H13B0.47660.51830.65920.047*
H13C0.41300.28870.65260.047*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S0.0226 (3)0.0218 (3)0.0288 (3)0.00298 (17)0.00704 (18)0.00404 (18)
O10.0180 (6)0.0248 (7)0.0181 (6)0.0020 (5)0.0039 (4)0.0033 (5)
O20.0245 (7)0.0204 (7)0.0432 (8)0.0008 (5)0.0081 (6)0.0012 (6)
O30.0204 (6)0.0229 (7)0.0377 (7)0.0021 (5)0.0005 (5)0.0019 (6)
C10.0161 (8)0.0183 (8)0.0211 (8)0.0002 (6)0.0021 (6)0.0017 (7)
C20.0157 (8)0.0201 (9)0.0192 (8)0.0011 (6)0.0009 (6)0.0004 (7)
C30.0239 (9)0.0265 (10)0.0196 (8)0.0009 (7)0.0041 (7)0.0021 (7)
C40.0266 (9)0.0251 (10)0.0206 (8)0.0013 (7)0.0002 (7)0.0060 (7)
C50.0179 (8)0.0190 (9)0.0277 (9)0.0006 (6)0.0019 (7)0.0017 (7)
C60.0165 (8)0.0190 (9)0.0258 (9)0.0008 (6)0.0027 (6)0.0019 (7)
C70.0171 (8)0.0195 (9)0.0178 (8)0.0019 (6)0.0009 (6)0.0014 (7)
C80.0153 (8)0.0186 (9)0.0218 (8)0.0012 (6)0.0011 (6)0.0010 (7)
C90.0256 (10)0.0243 (10)0.0384 (11)0.0052 (7)0.0012 (8)0.0028 (8)
C100.0259 (10)0.0350 (11)0.0354 (10)0.0061 (8)0.0106 (8)0.0015 (9)
C110.0206 (9)0.0203 (9)0.0221 (8)0.0014 (7)0.0006 (7)0.0047 (7)
C120.0218 (9)0.0209 (9)0.0156 (7)0.0002 (7)0.0032 (6)0.0027 (7)
C130.0258 (10)0.0310 (11)0.0402 (11)0.0012 (8)0.0127 (8)0.0018 (9)
Geometric parameters (Å, º) top
S—C11.7506 (17)C5—C91.507 (2)
S—C131.803 (2)C6—C71.388 (2)
O1—C81.383 (2)C6—C101.502 (2)
O1—C71.387 (2)C8—C111.491 (2)
O2—C121.312 (2)C9—H9A0.9800
O2—H2O0.83 (3)C9—H9B0.9800
O3—C121.212 (2)C9—H9C0.9800
C1—C81.348 (2)C10—H10A0.9800
C1—C21.449 (2)C10—H10B0.9800
C2—C71.388 (2)C10—H10C0.9800
C2—C31.392 (2)C11—C121.512 (2)
C3—C41.385 (3)C11—H11A0.9900
C3—H30.9500C11—H11B0.9900
C4—C51.404 (3)C13—H13A0.9800
C4—H40.9500C13—H13B0.9800
C5—C61.407 (2)C13—H13C0.9800
C1—S—C1399.52 (9)C5—C9—H9A109.5
C8—O1—C7105.6 (1)C5—C9—H9B109.5
C12—O2—H2O110 (2)H9A—C9—H9B109.5
C8—C1—C2106.5 (2)C5—C9—H9C109.5
C8—C1—S125.5 (1)H9A—C9—H9C109.5
C2—C1—S127.9 (1)H9B—C9—H9C109.5
C7—C2—C3119.2 (2)C6—C10—H10A109.5
C7—C2—C1105.6 (1)C6—C10—H10B109.5
C3—C2—C1135.3 (2)H10A—C10—H10B109.5
C4—C3—C2117.3 (2)C6—C10—H10C109.5
C4—C3—H3121.3H10A—C10—H10C109.5
C2—C3—H3121.3H10B—C10—H10C109.5
C3—C4—C5122.9 (2)C8—C11—C12112.5 (1)
C3—C4—H4118.6C8—C11—H11A109.1
C5—C4—H4118.6C12—C11—H11A109.1
C4—C5—C6120.4 (2)C8—C11—H11B109.1
C4—C5—C9119.3 (2)C12—C11—H11B109.1
C6—C5—C9120.3 (2)H11A—C11—H11B107.8
C7—C6—C5115.0 (2)O3—C12—O2123.7 (2)
C7—C6—C10121.9 (2)O3—C12—C11122.7 (2)
C5—C6—C10123.1 (2)O2—C12—C11113.5 (2)
O1—C7—C6124.4 (2)S—C13—H13A109.5
O1—C7—C2110.4 (1)S—C13—H13B109.5
C6—C7—C2125.3 (2)H13A—C13—H13B109.5
C1—C8—O1111.9 (2)S—C13—H13C109.5
C1—C8—C11131.4 (2)H13A—C13—H13C109.5
O1—C8—C11116.7 (2)H13B—C13—H13C109.5
C13—S—C1—C896.66 (17)C10—C6—C7—O10.7 (3)
C13—S—C1—C280.90 (17)C5—C6—C7—C20.8 (3)
C8—C1—C2—C70.11 (19)C10—C6—C7—C2178.93 (17)
S—C1—C2—C7177.82 (13)C3—C2—C7—O1179.69 (15)
C8—C1—C2—C3179.6 (2)C1—C2—C7—O10.06 (18)
S—C1—C2—C32.5 (3)C3—C2—C7—C60.6 (3)
C7—C2—C3—C40.1 (3)C1—C2—C7—C6179.65 (16)
C1—C2—C3—C4179.80 (19)C2—C1—C8—O10.13 (19)
C2—C3—C4—C50.0 (3)S—C1—C8—O1177.87 (12)
C3—C4—C5—C60.3 (3)C2—C1—C8—C11178.24 (17)
C3—C4—C5—C9179.47 (17)S—C1—C8—C110.2 (3)
C4—C5—C6—C70.7 (2)C7—O1—C8—C10.09 (18)
C9—C5—C6—C7179.84 (16)C7—O1—C8—C11178.51 (14)
C4—C5—C6—C10179.11 (17)C1—C8—C11—C1272.5 (2)
C9—C5—C6—C100.1 (3)O1—C8—C11—C12105.56 (17)
C8—O1—C7—C6179.73 (16)C8—C11—C12—O3138.89 (18)
C8—O1—C7—C20.01 (18)C8—C11—C12—O242.1 (2)
C5—C6—C7—O1179.48 (15)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C9—H9A···Cgi0.982.863.617 (2)135
O2—H2O···O3ii0.83 (3)1.89 (3)2.717 (2)175 (3)
Symmetry codes: (i) x, y1, z; (ii) x+1, y+1, z+2.

Experimental details

Crystal data
Chemical formulaC13H14O3S
Mr250.30
Crystal system, space groupMonoclinic, P21/c
Temperature (K)173
a, b, c (Å)18.050 (2), 4.9422 (5), 13.885 (1)
β (°) 104.451 (2)
V3)1199.4 (2)
Z4
Radiation typeMo Kα
µ (mm1)0.26
Crystal size (mm)0.40 × 0.20 × 0.10
Data collection
DiffractometerBruker SMART CCD
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
6673, 2595, 2269
Rint0.035
(sin θ/λ)max1)0.638
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.119, 1.17
No. of reflections2595
No. of parameters161
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.42, 0.25

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···AD—HH···AD···AD—H···A
C9—H9A···Cgi0.982.863.617 (2)135
O2—H2O···O3ii0.83 (3)1.89 (3)2.717 (2)175 (3)
Symmetry codes: (i) x, y1, z; (ii) x+1, y+1, z+2.
 

References

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

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