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organic compounds
2-(5-Fluoro-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
The title compound, C11H9FO3S, was prepared by alkaline hydrolysis of ethyl 2-(5-fluoro-3-methylsulfanyl-1-benzofuran-2-yl)acetate. In the 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 b axis by intermolecular C—H⋯O and C—H⋯F interactions.
Related literature
For the crystal structures of similar 2-(3-methylsulfanyl-1-benzofuran-2-yl) acetic acid derivatives, see: Choi et al. (2009a,b
). For the pharmacological activity of benzofuran compounds, see: Howlett et al. (1999
); Twyman & Allsop (1999
).
Experimental
Crystal data
|
Refinement
|
|
Data collection: SMART (Bruker, 2001); cell 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
10.1107/S160053680902594X/rn2061sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S160053680902594X/rn2061Isup2.hkl
Ethyl 2-(5-fluoro-3-methylsulfanyl-1-benzofuran-2-yl)acetate (402 mg, 1.5 mmol) was added to a solution of potassium hydroxide (505 mg, 9.0 mmol) in water (20 ml) and methanol (20 ml), and the mixture was refluxed for 6h, 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
(ethyl acetate) to afford the title compound as a colorless solid [yield 84%, m.p. 438-439 K; Rf = 0.6 (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.The H atom of O2 was positioned in a difference Fourier map and refined freely. The other H atoms were positioned geometrically and refined using a riding model, with C–H = 0.93 Å for the aryl, 0.97 Å for the methylene, and 0.96 Å for the methyl H atoms with Uiso(H) = 1.2Ueq(C) for the aryl and methylene H atoms, and 1.5Ueq(C) for methyl H atoms.
Data collection: SMART (Bruker, 2001); cell
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).C11H9FO3S | F(000) = 496 |
Mr = 240.24 | Dx = 1.536 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3920 reflections |
a = 7.5179 (4) Å | θ = 2.2–27.5° |
b = 27.325 (2) Å | µ = 0.31 mm−1 |
c = 5.0582 (3) Å | T = 173 K |
β = 90.478 (1)° | Block, colourless |
V = 1039.05 (11) Å3 | 0.40 × 0.40 × 0.20 mm |
Z = 4 |
Bruker SMART CCD diffractometer | 2015 independent reflections |
Radiation source: fine-focus sealed tube | 1758 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.016 |
Detector resolution: 10.0 pixels mm-1 | θmax = 26.0°, θmin = 2.8° |
ϕ and ω scans | h = −8→9 |
Absorption correction: multi-scan (SADABS; Sheldrick, 1999) | k = −33→31 |
Tmin = 0.885, Tmax = 0.940 | l = −5→6 |
5774 measured reflections |
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)] = 0.028 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.076 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0321P)2 + 0.495P] where P = (Fo2 + 2Fc2)/3 |
2015 reflections | (Δ/σ)max < 0.001 |
150 parameters | Δρmax = 0.26 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
C11H9FO3S | V = 1039.05 (11) Å3 |
Mr = 240.24 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.5179 (4) Å | µ = 0.31 mm−1 |
b = 27.325 (2) Å | T = 173 K |
c = 5.0582 (3) Å | 0.40 × 0.40 × 0.20 mm |
β = 90.478 (1)° |
Bruker SMART CCD diffractometer | 2015 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1999) | 1758 reflections with I > 2σ(I) |
Tmin = 0.885, Tmax = 0.940 | Rint = 0.016 |
5774 measured reflections |
R[F2 > 2σ(F2)] = 0.028 | 0 restraints |
wR(F2) = 0.076 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | Δρmax = 0.26 e Å−3 |
2015 reflections | Δρmin = −0.21 e Å−3 |
150 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
S | 0.31784 (5) | 0.316516 (15) | 0.58563 (8) | 0.02756 (13) | |
F | 0.83216 (14) | 0.28556 (4) | −0.2451 (2) | 0.0378 (3) | |
O1 | 0.59504 (15) | 0.43332 (4) | 0.3745 (2) | 0.0255 (3) | |
O2 | 0.19605 (18) | 0.46681 (5) | 0.3551 (2) | 0.0343 (3) | |
H2 | 0.102 (3) | 0.4823 (9) | 0.316 (4) | 0.047 (6)* | |
O3 | 0.09836 (15) | 0.48144 (4) | 0.7637 (2) | 0.0268 (3) | |
C1 | 0.4579 (2) | 0.36074 (6) | 0.4469 (3) | 0.0217 (3) | |
C2 | 0.58779 (19) | 0.35365 (6) | 0.2404 (3) | 0.0211 (3) | |
C3 | 0.6420 (2) | 0.31379 (6) | 0.0878 (3) | 0.0231 (3) | |
H3 | 0.5921 | 0.2829 | 0.1067 | 0.028* | |
C4 | 0.7740 (2) | 0.32324 (6) | −0.0924 (3) | 0.0251 (3) | |
C5 | 0.8516 (2) | 0.36865 (6) | −0.1307 (3) | 0.0277 (4) | |
H5 | 0.9394 | 0.3725 | −0.2575 | 0.033* | |
C6 | 0.7982 (2) | 0.40828 (6) | 0.0203 (3) | 0.0264 (3) | |
H6 | 0.8478 | 0.4392 | −0.0006 | 0.032* | |
C7 | 0.6668 (2) | 0.39915 (6) | 0.2039 (3) | 0.0224 (3) | |
C8 | 0.4683 (2) | 0.40835 (6) | 0.5179 (3) | 0.0232 (3) | |
C9 | 0.3703 (2) | 0.43787 (6) | 0.7168 (3) | 0.0277 (4) | |
H9A | 0.4513 | 0.4620 | 0.7909 | 0.033* | |
H9B | 0.3345 | 0.4164 | 0.8594 | 0.033* | |
C10 | 0.2076 (2) | 0.46410 (5) | 0.6137 (3) | 0.0219 (3) | |
C11 | 0.1570 (2) | 0.30916 (8) | 0.3207 (3) | 0.0372 (4) | |
H11A | 0.0973 | 0.3397 | 0.2896 | 0.056* | |
H11B | 0.0715 | 0.2847 | 0.3690 | 0.056* | |
H11C | 0.2169 | 0.2991 | 0.1627 | 0.056* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S | 0.0263 (2) | 0.0334 (2) | 0.0230 (2) | −0.00356 (16) | 0.00305 (15) | 0.00559 (16) |
F | 0.0415 (6) | 0.0317 (5) | 0.0406 (6) | 0.0029 (4) | 0.0146 (5) | −0.0114 (4) |
O1 | 0.0268 (6) | 0.0213 (5) | 0.0285 (6) | 0.0022 (4) | 0.0046 (5) | −0.0023 (4) |
O2 | 0.0339 (7) | 0.0485 (8) | 0.0207 (6) | 0.0195 (6) | 0.0010 (5) | −0.0011 (5) |
O3 | 0.0251 (6) | 0.0318 (6) | 0.0234 (6) | 0.0067 (5) | 0.0057 (4) | 0.0003 (4) |
C1 | 0.0189 (7) | 0.0249 (8) | 0.0215 (7) | 0.0035 (6) | 0.0008 (6) | 0.0025 (6) |
C2 | 0.0174 (7) | 0.0238 (8) | 0.0219 (7) | 0.0022 (6) | −0.0014 (6) | 0.0025 (6) |
C3 | 0.0226 (8) | 0.0211 (7) | 0.0257 (8) | 0.0011 (6) | −0.0012 (6) | 0.0008 (6) |
C4 | 0.0237 (8) | 0.0261 (8) | 0.0254 (8) | 0.0051 (6) | 0.0009 (6) | −0.0048 (6) |
C5 | 0.0216 (8) | 0.0346 (9) | 0.0269 (8) | −0.0005 (7) | 0.0050 (6) | 0.0007 (7) |
C6 | 0.0241 (8) | 0.0243 (8) | 0.0308 (8) | −0.0033 (6) | 0.0027 (6) | 0.0011 (6) |
C7 | 0.0216 (8) | 0.0212 (7) | 0.0244 (7) | 0.0029 (6) | −0.0003 (6) | −0.0016 (6) |
C8 | 0.0202 (8) | 0.0275 (8) | 0.0218 (7) | 0.0045 (6) | 0.0008 (6) | 0.0017 (6) |
C9 | 0.0286 (9) | 0.0319 (9) | 0.0224 (8) | 0.0085 (7) | 0.0005 (6) | −0.0028 (6) |
C10 | 0.0236 (8) | 0.0197 (7) | 0.0225 (7) | −0.0001 (6) | 0.0028 (6) | −0.0015 (6) |
C11 | 0.0322 (10) | 0.0500 (11) | 0.0293 (9) | −0.0112 (8) | 0.0006 (7) | −0.0013 (8) |
S—C1 | 1.753 (2) | C3—H3 | 0.9300 |
S—C11 | 1.809 (2) | C4—C5 | 1.385 (2) |
F—C4 | 1.361 (2) | C5—C6 | 1.386 (2) |
O1—C8 | 1.382 (2) | C5—H5 | 0.9300 |
O1—C7 | 1.384 (2) | C6—C7 | 1.385 (2) |
O2—C10 | 1.312 (2) | C6—H6 | 0.9300 |
O2—H2 | 0.84 (2) | C8—C9 | 1.489 (2) |
O3—C10 | 1.219 (2) | C9—C10 | 1.507 (2) |
C1—C8 | 1.352 (2) | C9—H9A | 0.9700 |
C1—C2 | 1.449 (2) | C9—H9B | 0.9700 |
C2—C7 | 1.391 (2) | C11—H11A | 0.9600 |
C2—C3 | 1.398 (2) | C11—H11B | 0.9600 |
C3—C4 | 1.378 (2) | C11—H11C | 0.9600 |
C1—S—C11 | 100.36 (8) | O1—C7—C6 | 125.50 (14) |
C8—O1—C7 | 105.54 (12) | O1—C7—C2 | 110.57 (13) |
C10—O2—H2 | 107.9 (15) | C6—C7—C2 | 123.93 (14) |
C8—C1—C2 | 106.38 (13) | C1—C8—O1 | 111.99 (13) |
C8—C1—S | 126.22 (12) | C1—C8—C9 | 132.27 (15) |
C2—C1—S | 127.38 (12) | O1—C8—C9 | 115.73 (14) |
C7—C2—C3 | 119.76 (14) | C8—C9—C10 | 115.38 (13) |
C7—C2—C1 | 105.51 (13) | C8—C9—H9A | 108.4 |
C3—C2—C1 | 134.72 (14) | C10—C9—H9A | 108.4 |
C4—C3—C2 | 115.75 (14) | C8—C9—H9B | 108.4 |
C4—C3—H3 | 122.1 | C10—C9—H9B | 108.4 |
C2—C3—H3 | 122.1 | H9A—C9—H9B | 107.5 |
F—C4—C3 | 118.04 (14) | O3—C10—O2 | 123.98 (15) |
F—C4—C5 | 117.43 (14) | O3—C10—C9 | 121.25 (14) |
C3—C4—C5 | 124.53 (14) | O2—C10—C9 | 114.76 (13) |
C4—C5—C6 | 119.90 (14) | S—C11—H11A | 109.5 |
C4—C5—H5 | 120.0 | S—C11—H11B | 109.5 |
C6—C5—H5 | 120.0 | H11A—C11—H11B | 109.5 |
C7—C6—C5 | 116.12 (15) | S—C11—H11C | 109.5 |
C7—C6—H6 | 121.9 | H11A—C11—H11C | 109.5 |
C5—C6—H6 | 121.9 | H11B—C11—H11C | 109.5 |
C11—S—C1—C8 | 107.19 (15) | C5—C6—C7—C2 | −0.6 (2) |
C11—S—C1—C2 | −74.59 (15) | C3—C2—C7—O1 | −179.70 (13) |
C8—C1—C2—C7 | −0.23 (17) | C1—C2—C7—O1 | 0.38 (17) |
S—C1—C2—C7 | −178.73 (12) | C3—C2—C7—C6 | 0.6 (2) |
C8—C1—C2—C3 | 179.87 (17) | C1—C2—C7—C6 | −179.33 (15) |
S—C1—C2—C3 | 1.4 (3) | C2—C1—C8—O1 | −0.01 (17) |
C7—C2—C3—C4 | 0.0 (2) | S—C1—C8—O1 | 178.52 (11) |
C1—C2—C3—C4 | 179.93 (16) | C2—C1—C8—C9 | 179.85 (16) |
C2—C3—C4—F | 179.70 (14) | S—C1—C8—C9 | −1.6 (3) |
C2—C3—C4—C5 | −0.7 (2) | C7—O1—C8—C1 | 0.24 (17) |
F—C4—C5—C6 | −179.66 (14) | C7—O1—C8—C9 | −179.65 (13) |
C3—C4—C5—C6 | 0.7 (3) | C1—C8—C9—C10 | −92.8 (2) |
C4—C5—C6—C7 | −0.1 (2) | O1—C8—C9—C10 | 87.07 (18) |
C8—O1—C7—C6 | 179.32 (15) | C8—C9—C10—O3 | 165.74 (15) |
C8—O1—C7—C2 | −0.39 (16) | C8—C9—C10—O2 | −14.8 (2) |
C5—C6—C7—O1 | 179.77 (14) |
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6···O3i | 0.93 | 2.52 | 3.2896 (19) | 141 |
C6—H6···O3ii | 0.93 | 2.51 | 3.296 (2) | 143 |
O2—H2···O3iii | 0.84 (2) | 1.85 (2) | 2.6902 (17) | 178 (2) |
C11—H11B···Fiv | 0.96 | 2.69 | 3.572 (2) | 153 |
C11—H11B···Fv | 0.96 | 2.67 | 3.361 (2) | 130 |
Symmetry codes: (i) x+1, y, z−1; (ii) −x+1, −y+1, −z+1; (iii) −x, −y+1, −z+1; (iv) x−1, −y+1/2, z+1/2; (v) x−1, y, z+1. |
Experimental details
Crystal data | |
Chemical formula | C11H9FO3S |
Mr | 240.24 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 173 |
a, b, c (Å) | 7.5179 (4), 27.325 (2), 5.0582 (3) |
β (°) | 90.478 (1) |
V (Å3) | 1039.05 (11) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.31 |
Crystal size (mm) | 0.40 × 0.40 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1999) |
Tmin, Tmax | 0.885, 0.940 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5774, 2015, 1758 |
Rint | 0.016 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.028, 0.076, 1.10 |
No. of reflections | 2015 |
No. of parameters | 150 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.26, −0.21 |
Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998).
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6···O3i | 0.93 | 2.52 | 3.2896 (19) | 140.6 |
C6—H6···O3ii | 0.93 | 2.51 | 3.296 (2) | 142.6 |
O2—H2···O3iii | 0.84 (2) | 1.85 (2) | 2.6902 (17) | 178 (2) |
C11—H11B···Fiv | 0.96 | 2.69 | 3.572 (2) | 152.8 |
C11—H11B···Fv | 0.96 | 2.67 | 3.361 (2) | 129.7 |
Symmetry codes: (i) x+1, y, z−1; (ii) −x+1, −y+1, −z+1; (iii) −x, −y+1, −z+1; (iv) x−1, −y+1/2, z+1/2; (v) x−1, y, z+1. |
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. (2009a). Acta Cryst. E65, o563. Web of Science CSD CrossRef IUCr Journals Google Scholar
Choi, H. D., Seo, P. J., Son, B. W. & Lee, U. (2009b). Acta Cryst. E65, o1527. Web of Science CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Howlett, D. R., Perry, A. E., Godfrey, F., Swatton, J. E., Jennings, K. H., Spitzfaden, C., Wadsworth, H., Wood, S. J. & Markwell, R. E. (1999). Biochem. J. 340, 283–289. Web of Science CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (1999). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Twyman, L. J. & Allsop, D. (1999). Tetrahedron Lett. 40, 9383–9384. Web of Science CrossRef CAS Google Scholar
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The benzofuran ring systems have been attracted considerable interest in the view of their pharmacological properties (Howlett et al., 1999; Twyman & Allsop, 1999). As a part of our ongoing studies on the synthesis and structures of 2-(3-methylsulfanyl-1-benzofuran-2-yl)acetic acid analogues, the crystal structure of 2-(5-bromo-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid (Choi et al., 2009a) and 2-(5-isopropyl-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid (Choi et al., 2009b) have been described in the literature. Here we report the crystal structure of the title compound, 2-(5-fluoro-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid (Fig. 1).
The benzofuran unit is essentially planar, with a mean deviation of 0.005 (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 (Table 1 and Fig. 2), which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along the b axis by intermolecular C–H···O and C–H···F interactions; the first between an H atom of benzofuran ring and the C═O unit, with C6–H6···O3i and C6–H6···O3ii, the second between a methyl H atom of methylsulfanyl group and the fluorine atom of the benzofuran ring, with C11–H11B···Fiv and C11–H11B···Fv, respectively (Table 1 and Fig. 2).