5-Bromo­thio­phene-2-sulfonic acid

In the title compound, C₄H₃BrO₃S₂, all bond lengths and angles are within normal ranges. The crystal packing exhibits inter­molecular O—H...O hydrogen bonds, which link the mol­ecules into chains extended along the c axis.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.008 Å
• R factor = 0.050
• wR factor = 0.134
• Data-to-parameter ratio = 14.5

checkCIF/PLATON results

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Alert level C
PLAT341_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          8

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Some sulfonamide compounds exhibit germicidal activities (Gayathri et al., 2006; Krishnaiah et al., 1995; Yu, 2006), and some crystal structures involving sulfonamide groups have been published (Yan et al., 2007; Lin et al., 2007). 5-Bromothiophene-2-sulfonyl chloride is an important starting material used in synthesis of sulfonamide compounds. Recently, during our synthesis of sulfonamide compounds, the hydrolysate of 5-bromothiophene-2-sulfonyl chloride was obtained unexpectedly. Here we report the crystal structure of the title compound, (I).

In (I) (Fig. 1), all bond lengths and angles show normal values (Allen et al., 1987) and are unremarkable when compared with those found in previous reports (Yan et al., 2007; Lin et al., 2007). The crystal packing exhibits intermolecular O—H···O hydrogen bonds (Table 1), which link the molecules into the chains extended along the c axis.

Related literature

For general background, see Yan et al. (2007). For related literature, see: Allen et al. (1987); Lin et al. (2007). For details of the pharmacological properties of sulfonamide compounds, see: Gayathri et al. (2006); Krishnaiah et al. (1995); Yu (2006).

S2. Experimental

5-Bromothiophene-2-sulfonyl chloride (5 mmol, 1.304 g), 2-aminobenzoic acid (5 mmol, 0.685 g) and N,N-dimethylpyridin-4-amine (DMAP) (0.5 mmol, 0.061 g) were added to acetone (15 ml) at room temperature with stirring. The reaction was allowed to proceed for 48 h at room temperature, followed by column chromatographic separation. The purified product was dissoved in ethanol–acetone (1:1), and allowed to stand for approximately 15 d until single crystals formed.

S3. Refinement

The atom H3 was located on a difference Fourier map, placed in idealized position (O—H 0.82 Å) and refined as riding, with U_iso(H3) = 1.5U_eq(O3). C-bound H atoms were positioned geometrically, and were allowed to ride on their parent atoms at distances of C—H 0.93 Å, with U_iso(H) = 1.2U_eq(C). The highest residual peak [1.28 e Å^-3] and deepest hole [-1.21 e Å^-3] are situated 0.04 Å at atom S2 and 0.15 Å at atom O3, respectively.

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2002); software used to prepare material for publication: SHELXL97.

Figures

Fig. 1. A portion of the crystal packing of (I), showing the atom numbering and displacement ellipsoids at the 40% probability level [symmetry code: (A) -x + 3/2, y, z + 1/2]. Dashed line denotes intermolecular hydrogen bond.

5-Bromothiophene-2-sulfonic acid

Crystal data

C4H3BrO3S2	F(000) = 944
Mr = 243.09	Dx = 2.108 Mg m^−3
Orthorhombic, Pccn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ab 2ac	Cell parameters from 2560 reflections
a = 13.7633 (16) Å	θ = 2.8–25.0°
b = 14.4540 (17) Å	µ = 5.85 mm^−1
c = 7.7020 (9) Å	T = 298 K
V = 1532.2 (3) Å^3	Prism, colourless
Z = 8	0.32 × 0.21 × 0.12 mm

Data collection

Bruker APEX area-detector diffractometer	1347 independent reflections
Radiation source: fine-focus sealed tube	1191 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
φ and ω scans	θmax = 25.0°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2002)	h = −16→13
Tmin = 0.241, Tmax = 0.500	k = −17→17
7333 measured reflections	l = −9→9

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.050	H-atom parameters constrained
wR(F^2) = 0.134	w = 1/[σ^2(Fo^2) + (0.0718P)^2 + 4.907P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
1347 reflections	Δρmax = 1.28 e Å^−3
93 parameters	Δρmin = −1.22 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0100 (13)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Br1	1.17226 (5)	0.61516 (5)	1.03375 (11)	0.0594 (4)
S1	1.06565 (9)	0.80207 (10)	0.9827 (2)	0.0412 (4)
S2	0.88696 (9)	0.91154 (8)	0.88437 (17)	0.0346 (4)
O1	0.8001 (3)	0.8886 (3)	0.7904 (6)	0.0457 (10)
O2	0.9573 (3)	0.9723 (2)	0.8092 (5)	0.0395 (9)
O3	0.8528 (3)	0.9585 (3)	1.0626 (5)	0.0459 (10)
H3	0.8073	0.9291	1.1034	0.069*
C1	1.0605 (4)	0.6842 (4)	0.9861 (7)	0.0366 (12)
C2	0.9721 (4)	0.6498 (4)	0.9457 (7)	0.0405 (12)
H2	0.9574	0.5870	0.9417	0.049*
C3	0.9050 (4)	0.7209 (4)	0.9103 (7)	0.0377 (11)
H3A	0.8404	0.7105	0.8809	0.045*
C4	0.9452 (3)	0.8064 (3)	0.9237 (6)	0.0296 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0396 (5)	0.0554 (5)	0.0834 (6)	0.0193 (3)	−0.0019 (3)	0.0086 (3)
S1	0.0220 (7)	0.0379 (8)	0.0637 (9)	−0.0003 (5)	−0.0064 (5)	0.0044 (6)
S2	0.0294 (7)	0.0336 (7)	0.0408 (7)	−0.0015 (5)	−0.0021 (5)	0.0069 (5)
O1	0.0268 (19)	0.051 (2)	0.059 (3)	−0.0032 (16)	−0.0157 (18)	0.0120 (19)
O2	0.0332 (19)	0.0395 (19)	0.046 (2)	−0.0060 (15)	0.0035 (16)	0.0103 (16)
O3	0.038 (2)	0.048 (2)	0.052 (2)	0.0015 (18)	0.0066 (18)	−0.0026 (19)
C1	0.034 (3)	0.035 (3)	0.040 (3)	0.009 (2)	0.001 (2)	0.001 (2)
C2	0.042 (3)	0.032 (3)	0.048 (3)	0.001 (2)	−0.001 (2)	−0.002 (2)
C3	0.029 (3)	0.037 (3)	0.047 (3)	−0.004 (2)	−0.005 (2)	−0.001 (2)
C4	0.021 (2)	0.033 (3)	0.035 (3)	−0.0014 (18)	−0.0023 (18)	0.003 (2)

Geometric parameters (Å, º)

Br1—C1	1.870 (5)	O3—H3	0.8200
S1—C1	1.705 (5)	C1—C2	1.351 (8)
S1—C4	1.720 (5)	C2—C3	1.409 (7)
S2—O2	1.429 (4)	C2—H2	0.9300
S2—O1	1.437 (4)	C3—C4	1.358 (7)
S2—O3	1.602 (4)	C3—H3A	0.9300
S2—C4	1.745 (5)
C1—S1—C4	90.0 (3)	S1—C1—Br1	120.1 (3)
O2—S2—O1	120.1 (2)	C1—C2—C3	111.5 (5)
O2—S2—O3	106.6 (2)	C1—C2—H2	124.3
O1—S2—O3	106.6 (2)	C3—C2—H2	124.3
O2—S2—C4	107.1 (2)	C4—C3—C2	112.5 (5)
O1—S2—C4	105.6 (2)	C4—C3—H3A	123.8
O3—S2—C4	110.8 (2)	C2—C3—H3A	123.8
S2—O3—H3	109.5	C3—C4—S1	112.3 (4)
C2—C1—S1	113.7 (4)	C3—C4—S2	126.3 (4)
C2—C1—Br1	126.1 (4)	S1—C4—S2	121.4 (3)
C4—S1—C1—C2	−0.3 (4)	C1—S1—C4—S2	−178.4 (3)
C4—S1—C1—Br1	177.3 (3)	O2—S2—C4—C3	−144.9 (5)
S1—C1—C2—C3	0.0 (6)	O1—S2—C4—C3	−15.8 (5)
Br1—C1—C2—C3	−177.5 (4)	O3—S2—C4—C3	99.3 (5)
C1—C2—C3—C4	0.5 (7)	O2—S2—C4—S1	34.0 (4)
C2—C3—C4—S1	−0.8 (6)	O1—S2—C4—S1	163.1 (3)
C2—C3—C4—S2	178.2 (4)	O3—S2—C4—S1	−81.8 (3)
C1—S1—C4—C3	0.6 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O1^i	0.82	2.14	2.920 (5)	158

Symmetry code: (i) −x+3/2, y, z+1/2.