2-(5-Bromo-3-isopropyl­sulfanyl-1-benzofuran-2-yl)acetic acid

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

doi:10.1107/S1600536811052160

organic compounds

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ISSN: 2056-9890

Volume 68| Part 1| January 2012| Page o58

doi:10.1107/S1600536811052160

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2-(5-Bromo-3-isopropylsulfanyl-1-benzofuran-2-yl)acetic acid

Pil Ja Seo,^a Hong Dae Choi,^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 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 π–π 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 ); 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

Crystal data

C₁₃H₁₃BrO₃S
M_r = 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 ) T_min = 0.510, T_max = 0.738
11869 measured reflections
3082 independent reflections
2731 reflections with I > 2σ(I)
R_int = 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
Δρ_max = 0.52 e Å⁻³
Δρ_min = −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	D⋯A	D—H⋯A
O2—H2O⋯O3ⁱ	0.74 (3)	1.90 (3)	2.640 (2)	177 (3)
C9—H9B⋯Cg2ⁱⁱ	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); cell refinement: SAINT (Bruker, 2009); 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/S1600536811052160/bg2430sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811052160/bg2430Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811052160/bg2430Isup3.cml

checkCIF report

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 π–π 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; R_f = 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.

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

	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.
	Fig. 2. A view of the O—H···O, C—H···π and π–π 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

C₁₃H₁₃BrO₃S	Z = 2
M_r = 329.20	F(000) = 332
Triclinic, P1	D_x = 1.643 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.4689 (3) Å	Cell parameters from 5830 reflections
b = 9.9449 (4) Å	θ = 2.3–27.5°
c = 10.0653 (4) Å	µ = 3.24 mm⁻¹
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 anode	2731 reflections with I > 2σ(I)
Graphite multilayer monochromator	R_int = 0.030
Detector resolution: 10.0 pixels mm^-1	θ_max = 27.6°, θ_min = 2.1°
ϕ and ω scans	h = −9→9
Absorption correction: multi-scan (SADABS; Bruker, 2009)	k = −12→12
T_min = 0.510, T_max = 0.738	l = −13→13
11869 measured 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)] = 0.024	Hydrogen site location: difference Fourier map
wR(F²) = 0.064	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ²(F_o²) + (0.0351P)² + 0.1792P] where P = (F_o² + 2F_c²)/3
3082 reflections	(Δ/σ)_max = 0.001
169 parameters	Δρ_max = 0.52 e Å⁻³
0 restraints	Δρ_min = −0.30 e Å⁻³

Crystal data top

C₁₃H₁₃BrO₃S	γ = 110.341 (3)°
M_r = 329.20	V = 665.38 (5) Å³
Triclinic, P1	Z = 2
a = 7.4689 (3) Å	Mo Kα radiation
b = 9.9449 (4) Å	µ = 3.24 mm⁻¹
c = 10.0653 (4) Å	T = 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)
T_min = 0.510, T_max = 0.738	R_int = 0.030
11869 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.024	0 restraints
wR(F²) = 0.064	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	Δρ_max = 0.52 e Å⁻³
3082 reflections	Δρ_min = −0.30 e Å⁻³
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

	x	y	z	U_iso*/U_eq
Br1	0.19969 (3)	−0.066508 (19)	0.14451 (2)	0.03256 (8)
S1	0.19347 (6)	0.56388 (5)	0.18733 (4)	0.02002 (10)
O1	0.71390 (18)	0.55476 (13)	0.17068 (13)	0.0206 (2)
O2	0.8525 (2)	1.01742 (15)	0.34019 (17)	0.0322 (3)
H2O	0.925 (4)	1.059 (3)	0.409 (3)	0.050 (9)*
O3	0.8861 (2)	0.82564 (14)	0.41728 (14)	0.0290 (3)
C1	0.4055 (2)	0.52528 (18)	0.18780 (17)	0.0180 (3)
C2	0.4198 (2)	0.38295 (18)	0.17355 (17)	0.0176 (3)
C3	0.2914 (3)	0.24052 (18)	0.16819 (18)	0.0196 (3)
H3	0.1627	0.2202	0.1749	0.024*
C4	0.3645 (3)	0.13091 (19)	0.15246 (18)	0.0213 (3)
C5	0.5565 (3)	0.1574 (2)	0.14170 (19)	0.0227 (4)
H5	0.5989	0.0799	0.1316	0.027*
C6	0.6840 (3)	0.2986 (2)	0.14606 (19)	0.0223 (4)
H6	0.8119	0.3185	0.1379	0.027*
C7	0.6116 (2)	0.40805 (18)	0.16307 (17)	0.0190 (3)
C8	0.5840 (3)	0.62221 (18)	0.18556 (17)	0.0184 (3)
C9	0.6588 (3)	0.78314 (18)	0.19365 (18)	0.0207 (3)
H9A	0.5471	0.8131	0.1809	0.025*
H9B	0.7170	0.8019	0.1172	0.025*
C10	0.8114 (3)	0.87651 (19)	0.32922 (19)	0.0210 (3)
C11	0.2061 (3)	0.6058 (2)	0.37390 (19)	0.0252 (4)
H11	0.0865	0.6237	0.3795	0.030*
C12	0.3829 (3)	0.7457 (2)	0.4566 (2)	0.0377 (5)
H12A	0.3768	0.7682	0.5511	0.056*
H12B	0.3803	0.8259	0.4144	0.056*
H12C	0.5038	0.7317	0.4565	0.056*
C13	0.1986 (3)	0.4754 (2)	0.4379 (2)	0.0326 (4)
H13A	0.3110	0.4516	0.4314	0.049*
H13B	0.0780	0.3916	0.3882	0.049*
H13C	0.2020	0.5004	0.5344	0.049*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.03694 (13)	0.01654 (10)	0.04563 (14)	0.00761 (8)	0.01796 (10)	0.00961 (8)
S1	0.0193 (2)	0.0200 (2)	0.0201 (2)	0.00800 (17)	0.00334 (17)	0.00490 (16)
O1	0.0187 (6)	0.0170 (6)	0.0213 (6)	0.0032 (5)	0.0045 (5)	0.0012 (5)
O2	0.0399 (8)	0.0150 (6)	0.0274 (8)	0.0067 (6)	−0.0091 (7)	−0.0003 (5)
O3	0.0344 (7)	0.0161 (6)	0.0251 (7)	0.0052 (6)	−0.0054 (6)	0.0028 (5)
C1	0.0203 (8)	0.0175 (8)	0.0139 (8)	0.0061 (7)	0.0033 (6)	0.0025 (6)
C2	0.0196 (8)	0.0176 (8)	0.0125 (8)	0.0058 (7)	0.0024 (6)	0.0012 (6)
C3	0.0208 (8)	0.0190 (8)	0.0179 (8)	0.0061 (7)	0.0063 (7)	0.0041 (6)
C4	0.0249 (9)	0.0168 (8)	0.0186 (9)	0.0049 (7)	0.0051 (7)	0.0035 (6)
C5	0.0270 (9)	0.0209 (8)	0.0203 (9)	0.0119 (7)	0.0041 (7)	0.0025 (7)
C6	0.0190 (8)	0.0246 (9)	0.0205 (9)	0.0077 (7)	0.0043 (7)	0.0011 (7)
C7	0.0193 (8)	0.0189 (8)	0.0137 (8)	0.0034 (7)	0.0028 (6)	0.0013 (6)
C8	0.0214 (8)	0.0177 (8)	0.0134 (8)	0.0065 (7)	0.0027 (7)	0.0015 (6)
C9	0.0220 (8)	0.0160 (8)	0.0183 (9)	0.0026 (7)	0.0029 (7)	0.0032 (6)
C10	0.0215 (8)	0.0161 (8)	0.0217 (9)	0.0041 (7)	0.0051 (7)	0.0027 (6)
C11	0.0270 (9)	0.0309 (10)	0.0212 (9)	0.0140 (8)	0.0094 (8)	0.0056 (7)
C12	0.0431 (12)	0.0360 (12)	0.0241 (11)	0.0091 (10)	0.0077 (9)	−0.0030 (8)
C13	0.0361 (11)	0.0423 (12)	0.0268 (10)	0.0185 (10)	0.0136 (9)	0.0148 (9)

Geometric parameters (Å, º) top

Br1—C4	1.8996 (17)	C5—H5	0.9300
S1—C1	1.7533 (17)	C6—C7	1.378 (2)
S1—C11	1.8380 (18)	C6—H6	0.9300
O1—C7	1.373 (2)	C8—C9	1.484 (2)
O1—C8	1.378 (2)	C9—C10	1.504 (2)
O2—C10	1.308 (2)	C9—H9A	0.9700
O2—H2O	0.74 (3)	C9—H9B	0.9700
O3—C10	1.213 (2)	C11—C12	1.515 (3)
C1—C8	1.354 (2)	C11—C13	1.519 (3)
C1—C2	1.445 (2)	C11—H11	0.9800
C2—C3	1.393 (2)	C12—H12A	0.9600
C2—C7	1.396 (2)	C12—H12B	0.9600
C3—C4	1.382 (2)	C12—H12C	0.9600
C3—H3	0.9300	C13—H13A	0.9600
C4—C5	1.396 (3)	C13—H13B	0.9600
C5—C6	1.383 (3)	C13—H13C	0.9600

C1—S1—C11	103.26 (8)	C8—C9—C10	114.05 (14)
C7—O1—C8	105.80 (12)	C8—C9—H9A	108.7
C10—O2—H2O	108 (2)	C10—C9—H9A	108.7
C8—C1—C2	106.08 (14)	C8—C9—H9B	108.7
C8—C1—S1	125.91 (13)	C10—C9—H9B	108.7
C2—C1—S1	127.62 (13)	H9A—C9—H9B	107.6
C3—C2—C7	119.53 (15)	O3—C10—O2	124.59 (17)
C3—C2—C1	134.93 (15)	O3—C10—C9	123.37 (16)
C7—C2—C1	105.53 (14)	O2—C10—C9	112.04 (15)
C4—C3—C2	116.75 (15)	C12—C11—C13	112.01 (17)
C4—C3—H3	121.6	C12—C11—S1	112.33 (13)
C2—C3—H3	121.6	C13—C11—S1	111.88 (13)
C3—C4—C5	123.14 (16)	C12—C11—H11	106.7
C3—C4—Br1	119.60 (13)	C13—C11—H11	106.7
C5—C4—Br1	117.26 (13)	S1—C11—H11	106.7
C6—C5—C4	120.26 (16)	C11—C12—H12A	109.5
C6—C5—H5	119.9	C11—C12—H12B	109.5
C4—C5—H5	119.9	H12A—C12—H12B	109.5
C7—C6—C5	116.58 (16)	C11—C12—H12C	109.5
C7—C6—H6	121.7	H12A—C12—H12C	109.5
C5—C6—H6	121.7	H12B—C12—H12C	109.5
O1—C7—C6	125.78 (15)	C11—C13—H13A	109.5
O1—C7—C2	110.49 (14)	C11—C13—H13B	109.5
C6—C7—C2	123.73 (16)	H13A—C13—H13B	109.5
C1—C8—O1	112.10 (14)	C11—C13—H13C	109.5
C1—C8—C9	131.51 (16)	H13A—C13—H13C	109.5
O1—C8—C9	116.38 (14)	H13B—C13—H13C	109.5

C11—S1—C1—C8	−95.71 (16)	C3—C2—C7—O1	−179.98 (14)
C11—S1—C1—C2	92.46 (16)	C1—C2—C7—O1	0.32 (18)
C8—C1—C2—C3	−179.91 (18)	C3—C2—C7—C6	0.6 (3)
S1—C1—C2—C3	−6.8 (3)	C1—C2—C7—C6	−179.08 (16)
C8—C1—C2—C7	−0.27 (18)	C2—C1—C8—O1	0.13 (19)
S1—C1—C2—C7	172.85 (13)	S1—C1—C8—O1	−173.14 (12)
C7—C2—C3—C4	0.0 (2)	C2—C1—C8—C9	178.91 (17)
C1—C2—C3—C4	179.61 (18)	S1—C1—C8—C9	5.6 (3)
C2—C3—C4—C5	−0.2 (3)	C7—O1—C8—C1	0.06 (18)
C2—C3—C4—Br1	179.88 (12)	C7—O1—C8—C9	−178.91 (14)
C3—C4—C5—C6	−0.2 (3)	C1—C8—C9—C10	109.0 (2)
Br1—C4—C5—C6	179.71 (13)	O1—C8—C9—C10	−72.23 (19)
C4—C5—C6—C7	0.8 (3)	C8—C9—C10—O3	8.9 (3)
C8—O1—C7—C6	179.14 (17)	C8—C9—C10—O2	−170.96 (15)
C8—O1—C7—C2	−0.24 (17)	C1—S1—C11—C12	66.06 (16)
C5—C6—C7—O1	179.67 (16)	C1—S1—C11—C13	−60.93 (15)
C5—C6—C7—C2	−1.0 (3)

Hydrogen-bond geometry (Å, º) top

Cg2 is the centroid of the C2–C7 ring.

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2O···O3ⁱ	0.74 (3)	1.90 (3)	2.640 (2)	177 (3)
C9—H9B···Cg2ⁱⁱ	0.97	2.72 (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 formula	C₁₃H₁₃BrO₃S
M_r	329.20
Crystal system, space group	Triclinic, 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)
V (Å³)	665.38 (5)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	3.24
Crystal size (mm)	0.24 × 0.17 × 0.10

Data collection
Diffractometer	Bruker SMART APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.510, 0.738
No. of measured, independent and observed [I > 2σ(I)] reflections	11869, 3082, 2731
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.652

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.024, 0.064, 1.03
No. of reflections	3082
No. of parameters	169
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	D—H···A
O2—H2O···O3ⁱ	0.74 (3)	1.90 (3)	2.640 (2)	177 (3)
C9—H9B···Cg2ⁱⁱ	0.97	2.717 (2)	3.376 (2)	125.6

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

References

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Volume 68| Part 1| January 2012| Page o58

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