organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

2-(5-Bromo-3-iso­propyl­sulfanyl-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 3 November 2011; accepted 3 December 2011; online 10 December 2011)

The title compound, C13H13BrO3S, was prepared by alkaline hydrolysis of ethyl 2-(5-bromo-3-isopropyl­sulfanyl-1-benzofuran-2-yl)acetate. In the crystal, the carboxyl groups are involved in inter­molecular O—H⋯O hydrogen bonds, which link the mol­ecules into dimers. These dimers are further packed into stacks along the c axis by inter­molecular C—H⋯π inter­actions, and by slipped ππ inter­actions between the furan rings of adjacent mol­ecules [centroid–centroid distance = 3.472 (2) Å, inter­planar distance = 3.398 (2) Å and slippage = 0.713 (2) Å].

Related literature

For the pharmacological activity of benzofuran compounds, see: Aslam et al. (2009[Aslam, S. N., Stevenson, P. C., Kokubun, T. & Hall, D. R. (2009). Microbiol. Res. 164, 191-195.]); Galal et al. (2009[Galal, S. A., Abd El-All, A. S., Abdallah, M. M. & El-Diwani, H. I. (2009). Bioorg. Med. Chem. Lett. 19, 2420-2428.]); Khan et al. (2005[Khan, M. W., Alam, M. J., Rashid, M. A. & Chowdhury, R. (2005). Bioorg. Med. Chem. 13, 4796-4805.]). For natural products with benzofuran rings, see: Akgul & Anil (2003[Akgul, Y. Y. & Anil, H. (2003). Phytochemistry, 63, 939-943.]); Soekamto et al. (2003[Soekamto, N. H., Achmad, S. A., Ghisalberti, E. L., Hakim, E. H. & Syah, Y. M. (2003). Phytochemistry, 64, 831-834.]). For the crystal structures of related compounds, see: Choi et al. (2009a[Choi, H. D., Seo, P. J., Son, B. W. & Lee, U. (2009a). Acta Cryst. E65, o563.],b[Choi, H. D., Seo, P. J., Son, B. W. & Lee, U. (2009b). Acta Cryst. E65, o726.]).

[Scheme 1]

Experimental

Crystal data
  • C13H13BrO3S

  • Mr = 329.20

  • Triclinic, [P \overline 1]

  • a = 7.4689 (3) Å

  • b = 9.9449 (4) Å

  • c = 10.0653 (4) Å

  • α = 98.415 (2)°

  • β = 102.146 (2)°

  • γ = 110.341 (3)°

  • V = 665.38 (5) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 3.24 mm−1

  • T = 296 K

  • 0.24 × 0.17 × 0.10 mm

Data collection
  • Bruker SMART APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2. SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.510, Tmax = 0.738

  • 11869 measured reflections

  • 3082 independent reflections

  • 2731 reflections with I > 2σ(I)

  • Rint = 0.030

Refinement
  • R[F2 > 2σ(F2)] = 0.024

  • wR(F2) = 0.064

  • S = 1.03

  • 3082 reflections

  • 169 parameters

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

  • Δρmax = 0.52 e Å−3

  • Δρmin = −0.30 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

Cg2 is the centroid of the C2–C7 ring.

D—H⋯A D—H H⋯A DA D—H⋯A
O2—H2O⋯O3i 0.74 (3) 1.90 (3) 2.640 (2) 177 (3)
C9—H9BCg2ii 0.97 2.72 (1) 3.376 (2) 126
Symmetry codes: (i) -x+2, -y+2, -z+1; (ii) -x+1, -y+1, -z.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2. SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2. SADABS and SAINT. 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

Substituted benzofuran derivatives have attracted considerable interest in view of their valuable pharmacological properties such as antibacterial and antifungal, antitumor and antiviral, and antimicrobial activities (Aslam et al. , 2009, Galal et al. , 2009, Khan et al. , 2005). These benzofuran derivatives occur in a wide range of natural products (Akgul & Anil, 2003; Soekamto et al. , 2003). As a part of our ongoing study of 2-(5-bromo-1-benzofuran-2-yl) acetic acid analogues (Choi et al. , 2009a,b), we report herein the crystal structure of the title compound.

In the title molecule (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. In the crystal structure, the carboxyl groups are involved in intermolecular O—H···O hydrogen bonds (Table 1, first entry & Fig. 2), which link the molecules into centrosymmetric dimers. These dimers are further packed into stacks along the c axis by an intermolecular C—H···π interaction between a methylene H atom and the benzene ring (Table 1, second entry & Fig. 2), and by a weak slipped ππ interaction between the furan rings of adjacent molecules, with a Cg1···Cg1ii distance of 3.742 (2) Å and an interplanar distance of 3.398 (2) Å resulting in a slippage of 0.713 (2) Å (Fig. 2, Cg1 is the centroid of the C1-C2-C7-O1-C8 furan ring, (ii) -x+1, -y+1, -z.).

Related literature top

For the pharmacological activity of benzofuran compounds, see: Aslam et al. (2009); Galal et al. (2009); Khan et al. (2005). For natural products with benzofuran rings, see: Akgul & Anil (2003); Soekamto et al. (2003). For the crystal structures of related compounds, see: Choi et al. (2009a,b).

Experimental top

Ethyl 2-(5-bromo-3-isopropylsulfanyl-1-benzofuran-2-yl)acetate (428 mg, 1.2 mmol) was added to a solution of potassium hydroxide (337 mg. 6 mmol) in water (10 ml) and methanol (10 ml), and the mixture was refluxed for 5 h, then cooled. Water (10 ml) 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 at reduced pressure. The residue was purified by column chromatography (ethyl acetate) to afford the title compound as a colorless solid [yield 86%, m.p. 432–433 K; Rf = 0.51 (ethyl acetate)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in benzene at room temperature.

Refinement top

H atoms in the hydroxy group were found in a different Fourier map and refined freely. The other H atoms were positioned geometrically and refined using a riding model, with C–H = 0.93 Å fo the aryl, 0.98 Å for the methine, 0.97 Å for the methylene, and 0.96 Å for the methyl H atoms. Uiso(H) =1.2Ueq(C) for the aryl, methine, and methylene H atoms, and 1.5Ueq(C) for the methyl H atoms.

Computing details top

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 top
[Figure 1] 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 small spheres of arbitrary radius.
[Figure 2] Fig. 2. A view of the O—H···O, C—H···π and ππ interactions (dotted lines) in the crystal structure of the title compound. H atoms non-participating in hydrogen-bonding were omitted for clarity. [Symmetry codes: (i) - x + 2, - y + 2, - z + 1; (ii) - x + 1, - y + 1, - z.]
2-(5-Bromo-3-isopropylsulfanyl-1-benzofuran-2-yl)acetic acid top
Crystal data top
C13H13BrO3SZ = 2
Mr = 329.20F(000) = 332
Triclinic, P1Dx = 1.643 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.4689 (3) ÅCell parameters from 5830 reflections
b = 9.9449 (4) Åθ = 2.3–27.5°
c = 10.0653 (4) ŵ = 3.24 mm1
α = 98.415 (2)°T = 296 K
β = 102.146 (2)°Block, colourless
γ = 110.341 (3)°0.24 × 0.17 × 0.10 mm
V = 665.38 (5) Å3
Data collection top
Bruker SMART APEXII CCD
diffractometer
3082 independent reflections
Radiation source: rotating anode2731 reflections with I > 2σ(I)
Graphite multilayer monochromatorRint = 0.030
Detector resolution: 10.0 pixels mm-1θmax = 27.6°, θmin = 2.1°
ϕ and ω scansh = 99
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
k = 1212
Tmin = 0.510, Tmax = 0.738l = 1313
11869 measured 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)] = 0.024Hydrogen site location: difference Fourier map
wR(F2) = 0.064H atoms treated by a mixture of independent and constrained refinement
S = 1.03 w = 1/[σ2(Fo2) + (0.0351P)2 + 0.1792P]
where P = (Fo2 + 2Fc2)/3
3082 reflections(Δ/σ)max = 0.001
169 parametersΔρmax = 0.52 e Å3
0 restraintsΔρmin = 0.30 e Å3
Crystal data top
C13H13BrO3Sγ = 110.341 (3)°
Mr = 329.20V = 665.38 (5) Å3
Triclinic, P1Z = 2
a = 7.4689 (3) ÅMo Kα radiation
b = 9.9449 (4) ŵ = 3.24 mm1
c = 10.0653 (4) ÅT = 296 K
α = 98.415 (2)°0.24 × 0.17 × 0.10 mm
β = 102.146 (2)°
Data collection top
Bruker SMART APEXII CCD
diffractometer
3082 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
2731 reflections with I > 2σ(I)
Tmin = 0.510, Tmax = 0.738Rint = 0.030
11869 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0240 restraints
wR(F2) = 0.064H atoms treated by a mixture of independent and constrained refinement
S = 1.03Δρmax = 0.52 e Å3
3082 reflectionsΔρmin = 0.30 e Å3
169 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
Br10.19969 (3)0.066508 (19)0.14451 (2)0.03256 (8)
S10.19347 (6)0.56388 (5)0.18733 (4)0.02002 (10)
O10.71390 (18)0.55476 (13)0.17068 (13)0.0206 (2)
O20.8525 (2)1.01742 (15)0.34019 (17)0.0322 (3)
H2O0.925 (4)1.059 (3)0.409 (3)0.050 (9)*
O30.8861 (2)0.82564 (14)0.41728 (14)0.0290 (3)
C10.4055 (2)0.52528 (18)0.18780 (17)0.0180 (3)
C20.4198 (2)0.38295 (18)0.17355 (17)0.0176 (3)
C30.2914 (3)0.24052 (18)0.16819 (18)0.0196 (3)
H30.16270.22020.17490.024*
C40.3645 (3)0.13091 (19)0.15246 (18)0.0213 (3)
C50.5565 (3)0.1574 (2)0.14170 (19)0.0227 (4)
H50.59890.07990.13160.027*
C60.6840 (3)0.2986 (2)0.14606 (19)0.0223 (4)
H60.81190.31850.13790.027*
C70.6116 (2)0.40805 (18)0.16307 (17)0.0190 (3)
C80.5840 (3)0.62221 (18)0.18556 (17)0.0184 (3)
C90.6588 (3)0.78314 (18)0.19365 (18)0.0207 (3)
H9A0.54710.81310.18090.025*
H9B0.71700.80190.11720.025*
C100.8114 (3)0.87651 (19)0.32922 (19)0.0210 (3)
C110.2061 (3)0.6058 (2)0.37390 (19)0.0252 (4)
H110.08650.62370.37950.030*
C120.3829 (3)0.7457 (2)0.4566 (2)0.0377 (5)
H12A0.37680.76820.55110.056*
H12B0.38030.82590.41440.056*
H12C0.50380.73170.45650.056*
C130.1986 (3)0.4754 (2)0.4379 (2)0.0326 (4)
H13A0.31100.45160.43140.049*
H13B0.07800.39160.38820.049*
H13C0.20200.50040.53440.049*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.03694 (13)0.01654 (10)0.04563 (14)0.00761 (8)0.01796 (10)0.00961 (8)
S10.0193 (2)0.0200 (2)0.0201 (2)0.00800 (17)0.00334 (17)0.00490 (16)
O10.0187 (6)0.0170 (6)0.0213 (6)0.0032 (5)0.0045 (5)0.0012 (5)
O20.0399 (8)0.0150 (6)0.0274 (8)0.0067 (6)0.0091 (7)0.0003 (5)
O30.0344 (7)0.0161 (6)0.0251 (7)0.0052 (6)0.0054 (6)0.0028 (5)
C10.0203 (8)0.0175 (8)0.0139 (8)0.0061 (7)0.0033 (6)0.0025 (6)
C20.0196 (8)0.0176 (8)0.0125 (8)0.0058 (7)0.0024 (6)0.0012 (6)
C30.0208 (8)0.0190 (8)0.0179 (8)0.0061 (7)0.0063 (7)0.0041 (6)
C40.0249 (9)0.0168 (8)0.0186 (9)0.0049 (7)0.0051 (7)0.0035 (6)
C50.0270 (9)0.0209 (8)0.0203 (9)0.0119 (7)0.0041 (7)0.0025 (7)
C60.0190 (8)0.0246 (9)0.0205 (9)0.0077 (7)0.0043 (7)0.0011 (7)
C70.0193 (8)0.0189 (8)0.0137 (8)0.0034 (7)0.0028 (6)0.0013 (6)
C80.0214 (8)0.0177 (8)0.0134 (8)0.0065 (7)0.0027 (7)0.0015 (6)
C90.0220 (8)0.0160 (8)0.0183 (9)0.0026 (7)0.0029 (7)0.0032 (6)
C100.0215 (8)0.0161 (8)0.0217 (9)0.0041 (7)0.0051 (7)0.0027 (6)
C110.0270 (9)0.0309 (10)0.0212 (9)0.0140 (8)0.0094 (8)0.0056 (7)
C120.0431 (12)0.0360 (12)0.0241 (11)0.0091 (10)0.0077 (9)0.0030 (8)
C130.0361 (11)0.0423 (12)0.0268 (10)0.0185 (10)0.0136 (9)0.0148 (9)
Geometric parameters (Å, º) top
Br1—C41.8996 (17)C5—H50.9300
S1—C11.7533 (17)C6—C71.378 (2)
S1—C111.8380 (18)C6—H60.9300
O1—C71.373 (2)C8—C91.484 (2)
O1—C81.378 (2)C9—C101.504 (2)
O2—C101.308 (2)C9—H9A0.9700
O2—H2O0.74 (3)C9—H9B0.9700
O3—C101.213 (2)C11—C121.515 (3)
C1—C81.354 (2)C11—C131.519 (3)
C1—C21.445 (2)C11—H110.9800
C2—C31.393 (2)C12—H12A0.9600
C2—C71.396 (2)C12—H12B0.9600
C3—C41.382 (2)C12—H12C0.9600
C3—H30.9300C13—H13A0.9600
C4—C51.396 (3)C13—H13B0.9600
C5—C61.383 (3)C13—H13C0.9600
C1—S1—C11103.26 (8)C8—C9—C10114.05 (14)
C7—O1—C8105.80 (12)C8—C9—H9A108.7
C10—O2—H2O108 (2)C10—C9—H9A108.7
C8—C1—C2106.08 (14)C8—C9—H9B108.7
C8—C1—S1125.91 (13)C10—C9—H9B108.7
C2—C1—S1127.62 (13)H9A—C9—H9B107.6
C3—C2—C7119.53 (15)O3—C10—O2124.59 (17)
C3—C2—C1134.93 (15)O3—C10—C9123.37 (16)
C7—C2—C1105.53 (14)O2—C10—C9112.04 (15)
C4—C3—C2116.75 (15)C12—C11—C13112.01 (17)
C4—C3—H3121.6C12—C11—S1112.33 (13)
C2—C3—H3121.6C13—C11—S1111.88 (13)
C3—C4—C5123.14 (16)C12—C11—H11106.7
C3—C4—Br1119.60 (13)C13—C11—H11106.7
C5—C4—Br1117.26 (13)S1—C11—H11106.7
C6—C5—C4120.26 (16)C11—C12—H12A109.5
C6—C5—H5119.9C11—C12—H12B109.5
C4—C5—H5119.9H12A—C12—H12B109.5
C7—C6—C5116.58 (16)C11—C12—H12C109.5
C7—C6—H6121.7H12A—C12—H12C109.5
C5—C6—H6121.7H12B—C12—H12C109.5
O1—C7—C6125.78 (15)C11—C13—H13A109.5
O1—C7—C2110.49 (14)C11—C13—H13B109.5
C6—C7—C2123.73 (16)H13A—C13—H13B109.5
C1—C8—O1112.10 (14)C11—C13—H13C109.5
C1—C8—C9131.51 (16)H13A—C13—H13C109.5
O1—C8—C9116.38 (14)H13B—C13—H13C109.5
C11—S1—C1—C895.71 (16)C3—C2—C7—O1179.98 (14)
C11—S1—C1—C292.46 (16)C1—C2—C7—O10.32 (18)
C8—C1—C2—C3179.91 (18)C3—C2—C7—C60.6 (3)
S1—C1—C2—C36.8 (3)C1—C2—C7—C6179.08 (16)
C8—C1—C2—C70.27 (18)C2—C1—C8—O10.13 (19)
S1—C1—C2—C7172.85 (13)S1—C1—C8—O1173.14 (12)
C7—C2—C3—C40.0 (2)C2—C1—C8—C9178.91 (17)
C1—C2—C3—C4179.61 (18)S1—C1—C8—C95.6 (3)
C2—C3—C4—C50.2 (3)C7—O1—C8—C10.06 (18)
C2—C3—C4—Br1179.88 (12)C7—O1—C8—C9178.91 (14)
C3—C4—C5—C60.2 (3)C1—C8—C9—C10109.0 (2)
Br1—C4—C5—C6179.71 (13)O1—C8—C9—C1072.23 (19)
C4—C5—C6—C70.8 (3)C8—C9—C10—O38.9 (3)
C8—O1—C7—C6179.14 (17)C8—C9—C10—O2170.96 (15)
C8—O1—C7—C20.24 (17)C1—S1—C11—C1266.06 (16)
C5—C6—C7—O1179.67 (16)C1—S1—C11—C1360.93 (15)
C5—C6—C7—C21.0 (3)
Hydrogen-bond geometry (Å, º) top
Cg2 is the centroid of the C2–C7 ring.
D—H···AD—HH···AD···AD—H···A
O2—H2O···O3i0.74 (3)1.90 (3)2.640 (2)177 (3)
C9—H9B···Cg2ii0.972.72 (1)3.376 (2)126
Symmetry codes: (i) x+2, y+2, z+1; (ii) x+1, y+1, z.

Experimental details

Crystal data
Chemical formulaC13H13BrO3S
Mr329.20
Crystal system, space groupTriclinic, P1
Temperature (K)296
a, b, c (Å)7.4689 (3), 9.9449 (4), 10.0653 (4)
α, β, γ (°)98.415 (2), 102.146 (2), 110.341 (3)
V3)665.38 (5)
Z2
Radiation typeMo Kα
µ (mm1)3.24
Crystal size (mm)0.24 × 0.17 × 0.10
Data collection
DiffractometerBruker SMART APEXII CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.510, 0.738
No. of measured, independent and
observed [I > 2σ(I)] reflections
11869, 3082, 2731
Rint0.030
(sin θ/λ)max1)0.652
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.024, 0.064, 1.03
No. of reflections3082
No. of parameters169
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.52, 0.30

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 1998).

Hydrogen-bond geometry (Å, º) top
Cg2 is the centroid of the C2–C7 ring.
D—H···AD—HH···AD···AD—H···A
O2—H2O···O3i0.74 (3)1.90 (3)2.640 (2)177 (3)
C9—H9B···Cg2ii0.972.717 (2)3.376 (2)125.6
Symmetry codes: (i) x+2, y+2, z+1; (ii) x+1, y+1, z.
 

References

First citationAkgul, Y. Y. & Anil, H. (2003). Phytochemistry, 63, 939–943.  Web of Science CrossRef PubMed CAS
First citationAslam, S. N., Stevenson, P. C., Kokubun, T. & Hall, D. R. (2009). Microbiol. Res. 164, 191–195.  Web of Science CrossRef PubMed CAS
First citationBrandenburg, K. (1998). DIAMOND. Crystal Impact GbR, Bonn, Germany.
First citationBruker (2009). APEX2. SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
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