organic compounds
(S)-(−)-6-(4-Bromophenyl)-2,3,5,6-tetrahydrothiazolo[2,3-b]imidazolium hydrogen oxalate
aDepartment of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
*Correspondence e-mail: maks@iwonka.med.virginia.edu
The structure of the title compound, C11H12BrN2S+·C2HO4− (common name 6-bromolevamisole hydrogen oxalate), is stabilized mainly by hydrogen bonds. Hydrogen oxalate anions form parallel coplanar chains via O—H⋯O hydrogen bonds, while there are N—H⋯O hydrogen-bonding interactions between the 6-bromolevamisole cations and oxalate anions. Both five-membered rings from the 6-bromolevamisole molecule have a twist conformation. The molecule has an extended conformation, with the 4-bromophenyl substituent positioned equatorially with N—C—C—C and C—C—C—C torsion angles of 39.8 (3) and 100.4 (3)°, respectively.
Related literature
For background information, see: Denier et al. (2002); Lee et al. (1975); Luo et al. (2000).
Experimental
Crystal data
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Data collection: HKL-2000 (Otwinowski & Minor, 1997); cell HKL-2000; data reduction: HKL-2000; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008) and HKL-3000SM (Minor et al., 2006); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and HKL-3000SM; molecular graphics: HKL-3000SM, Mercury (Macrae et al., 2006), ORTEPIII (Burnett & Johnson, 1996) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: HKL-3000SM.
Supporting information
10.1107/S1600536808029085/fl2215sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808029085/fl2215Isup2.hkl
6-Bromolevamisole oxalate was purchased from Sigma, and dissolved in a mixture of 1-butanol and DMSO in a 1:1 ratio. A single crystal suitable for X-ray diffraction study was obtained by slow evaporation at room temperature.
Hydrogen atoms attached to C7, C8, and C9 were placed in ideal positions, and refined using a riding-model approximation with C—H bond lengths of 0.98 Å in the case of C7 and 0.97 Å in the cases of C8 and C9. All other hydrogen atoms were located in a difference density Fourier map and refined with isotropic displacement parameters.
Data collection: HKL-2000 (Otwinowski & Minor, 1997); cell
HKL-2000 (Otwinowski & Minor, 1997); data reduction: HKL-2000 (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008), HKL-3000SM (Minor et al., 2006); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008), HKL-3000SM (Minor et al., 2006); molecular graphics: HKL-3000SM (Minor et al., 2006), Mercury (Macrae et al., 2006), ORTEPIII (Burnett & Johnson, 1996) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: HKL-3000SM (Minor et al., 2006).C11H12BrN2S+·C2HO4− | Dx = 1.643 Mg m−3 |
Mr = 373.22 | Melting point: 465 K |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71074 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 39658 reflections |
a = 5.615 (1) Å | θ = 2.6–29.1° |
b = 8.256 (1) Å | µ = 2.88 mm−1 |
c = 32.539 (1) Å | T = 89 K |
V = 1508.4 (3) Å3 | Needle, colourless |
Z = 4 | 0.50 × 0.03 × 0.03 mm |
F(000) = 752 |
Rigaku R-AXIS RAPID diffractometer | 4061 independent reflections |
Radiation source: fine-focus sealed tube | 3438 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.081 |
Detector resolution: 10 pixels mm-1 | θmax = 29.1°, θmin = 2.6° |
ω scans with χ offset | h = −7→7 |
Absorption correction: multi-scan (Otwinowski et al., 2003) | k = −11→11 |
Tmin = 0.90, Tmax = 0.92 | l = −44→44 |
39658 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.032 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.074 | w = 1/[σ2(Fo2) + (0.0326P)2 + 0.8007P] where P = (Fo2 + 2Fc2)/3 |
S = 1.10 | (Δ/σ)max = 0.001 |
4061 reflections | Δρmax = 0.67 e Å−3 |
230 parameters | Δρmin = −0.51 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 1686 Friedel pairs? |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: −0.018 (7) |
C11H12BrN2S+·C2HO4− | V = 1508.4 (3) Å3 |
Mr = 373.22 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 5.615 (1) Å | µ = 2.88 mm−1 |
b = 8.256 (1) Å | T = 89 K |
c = 32.539 (1) Å | 0.50 × 0.03 × 0.03 mm |
Rigaku R-AXIS RAPID diffractometer | 4061 independent reflections |
Absorption correction: multi-scan (Otwinowski et al., 2003) | 3438 reflections with I > 2σ(I) |
Tmin = 0.90, Tmax = 0.92 | Rint = 0.081 |
39658 measured reflections |
R[F2 > 2σ(F2)] = 0.032 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.074 | Δρmax = 0.67 e Å−3 |
S = 1.10 | Δρmin = −0.51 e Å−3 |
4061 reflections | Absolute structure: Flack (1983), 1686 Friedel pairs? |
230 parameters | Absolute structure parameter: −0.018 (7) |
0 restraints |
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. |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.32101 (6) | 0.56744 (4) | 1.059826 (8) | 0.03817 (9) | |
S1 | 0.35196 (13) | 0.49266 (9) | 0.76858 (2) | 0.02854 (14) | |
N2 | 0.2692 (4) | 0.4064 (3) | 0.84952 (6) | 0.0204 (4) | |
C11 | 0.2064 (4) | 0.4764 (3) | 0.81524 (7) | 0.0196 (5) | |
C7 | 0.0668 (4) | 0.4192 (3) | 0.87900 (7) | 0.0198 (5) | |
H7 | −0.0267 | 0.3190 | 0.8781 | 0.024* | |
N1 | −0.0024 (4) | 0.5521 (3) | 0.81664 (6) | 0.0201 (4) | |
C8 | −0.0808 (4) | 0.5585 (3) | 0.85977 (7) | 0.0211 (5) | |
H8A | −0.2505 | 0.5387 | 0.8622 | 0.025* | |
H8B | −0.0427 | 0.6620 | 0.8723 | 0.025* | |
C9 | −0.0363 (6) | 0.6744 (4) | 0.78469 (8) | 0.0261 (6) | |
C1 | 0.1407 (4) | 0.4519 (3) | 0.92285 (7) | 0.0208 (5) | |
C2 | 0.3255 (5) | 0.5587 (3) | 0.93230 (7) | 0.0247 (5) | |
C10 | 0.0970 (6) | 0.6059 (4) | 0.74766 (9) | 0.0329 (7) | |
C3 | 0.3820 (5) | 0.5913 (4) | 0.97307 (9) | 0.0307 (6) | |
C5 | 0.0649 (5) | 0.4154 (4) | 0.99535 (9) | 0.0313 (6) | |
C6 | 0.0123 (6) | 0.3807 (4) | 0.95449 (9) | 0.0288 (6) | |
C4 | 0.2489 (5) | 0.5198 (3) | 1.00383 (8) | 0.0272 (6) | |
O3 | 0.8027 (3) | −0.0585 (2) | 0.84464 (5) | 0.0197 (3) | |
O4 | 0.6388 (3) | 0.1887 (2) | 0.84329 (6) | 0.0238 (4) | |
C1B | 0.6295 (4) | 0.0378 (3) | 0.84479 (7) | 0.0172 (5) | |
C2B | 0.3822 (4) | −0.0442 (3) | 0.84594 (7) | 0.0186 (5) | |
O1 | 0.2089 (3) | 0.0602 (2) | 0.84707 (6) | 0.0279 (4) | |
O2 | 0.3598 (3) | −0.1898 (2) | 0.84549 (7) | 0.0320 (5) | |
H2 | 0.405 (6) | 0.611 (4) | 0.9106 (11) | 0.040 (10)* | |
H5 | −0.032 (7) | 0.372 (5) | 1.0134 (12) | 0.051 (11)* | |
H10B | 0.158 (8) | 0.694 (5) | 0.7302 (12) | 0.058 (11)* | |
H9A | −0.201 (7) | 0.684 (4) | 0.7791 (9) | 0.027 (8)* | |
H3 | 0.500 (7) | 0.655 (4) | 0.9791 (10) | 0.037 (9)* | |
H9B | 0.031 (6) | 0.780 (4) | 0.7948 (9) | 0.027 (8)* | |
H10A | 0.009 (7) | 0.530 (5) | 0.7315 (12) | 0.052 (11)* | |
H6 | −0.104 (7) | 0.305 (5) | 0.9487 (10) | 0.045 (10)* | |
H1O | 0.042 (9) | 0.012 (5) | 0.8512 (14) | 0.076 (15)* | |
H1N | 0.361 (7) | 0.327 (4) | 0.8501 (11) | 0.044 (10)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0587 (2) | 0.03403 (15) | 0.02182 (11) | 0.00178 (15) | −0.00718 (13) | −0.00204 (11) |
S1 | 0.0306 (3) | 0.0314 (3) | 0.0237 (3) | 0.0028 (3) | 0.0062 (3) | −0.0047 (2) |
N2 | 0.0192 (10) | 0.0191 (11) | 0.0230 (9) | 0.0027 (8) | −0.0002 (8) | −0.0023 (8) |
C11 | 0.0207 (11) | 0.0133 (12) | 0.0248 (11) | −0.0011 (9) | −0.0004 (9) | −0.0053 (8) |
C7 | 0.0188 (11) | 0.0176 (12) | 0.0230 (11) | 0.0011 (10) | 0.0009 (9) | −0.0003 (9) |
N1 | 0.0192 (9) | 0.0205 (11) | 0.0206 (9) | 0.0028 (9) | −0.0001 (7) | −0.0001 (8) |
C8 | 0.0186 (11) | 0.0235 (12) | 0.0212 (10) | 0.0031 (11) | 0.0009 (8) | 0.0011 (10) |
C9 | 0.0315 (16) | 0.0259 (14) | 0.0209 (12) | 0.0032 (12) | −0.0035 (11) | 0.0018 (10) |
C1 | 0.0212 (12) | 0.0186 (12) | 0.0225 (10) | 0.0015 (10) | −0.0018 (9) | 0.0009 (9) |
C2 | 0.0248 (12) | 0.0240 (12) | 0.0254 (11) | −0.0056 (12) | 0.0014 (10) | −0.0017 (9) |
C10 | 0.0430 (18) | 0.0332 (16) | 0.0225 (12) | 0.0072 (13) | −0.0009 (12) | −0.0022 (11) |
C3 | 0.0328 (16) | 0.0310 (16) | 0.0282 (13) | −0.0079 (12) | −0.0028 (11) | −0.0046 (11) |
C5 | 0.0358 (15) | 0.0316 (16) | 0.0263 (12) | −0.0052 (13) | 0.0022 (11) | 0.0044 (12) |
C6 | 0.0315 (15) | 0.0262 (14) | 0.0285 (13) | −0.0081 (12) | −0.0030 (11) | 0.0025 (11) |
C4 | 0.0369 (14) | 0.0251 (13) | 0.0195 (11) | 0.0047 (11) | −0.0038 (10) | 0.0006 (9) |
O3 | 0.0130 (7) | 0.0178 (7) | 0.0285 (8) | 0.0007 (7) | 0.0008 (6) | −0.0009 (7) |
O4 | 0.0174 (9) | 0.0172 (8) | 0.0368 (9) | −0.0001 (7) | −0.0003 (8) | −0.0004 (7) |
C1B | 0.0153 (10) | 0.0211 (13) | 0.0153 (9) | 0.0003 (9) | 0.0006 (8) | −0.0010 (8) |
C2B | 0.0153 (11) | 0.0214 (13) | 0.0191 (10) | 0.0004 (9) | −0.0011 (8) | −0.0012 (9) |
O1 | 0.0113 (8) | 0.0192 (8) | 0.0532 (11) | 0.0004 (7) | 0.0000 (7) | −0.0015 (9) |
O2 | 0.0170 (9) | 0.0183 (9) | 0.0606 (13) | −0.0004 (7) | 0.0001 (9) | −0.0025 (9) |
Br1—C4 | 1.908 (3) | C1—C2 | 1.396 (4) |
S1—C11 | 1.729 (2) | C2—C3 | 1.390 (3) |
S1—C10 | 1.840 (3) | C2—H2 | 0.94 (4) |
N2—C11 | 1.305 (3) | C10—H10B | 0.98 (4) |
N2—C7 | 1.491 (3) | C10—H10A | 0.96 (4) |
N2—H1N | 0.83 (4) | C3—C4 | 1.382 (4) |
C11—N1 | 1.329 (3) | C3—H3 | 0.87 (4) |
C7—C1 | 1.510 (3) | C5—C4 | 1.373 (4) |
C7—C8 | 1.549 (3) | C5—C6 | 1.392 (4) |
C7—H7 | 0.9800 | C5—H5 | 0.88 (4) |
N1—C9 | 1.461 (3) | C6—H6 | 0.92 (4) |
N1—C8 | 1.472 (3) | O3—C1B | 1.257 (3) |
C8—H8A | 0.9700 | O4—C1B | 1.248 (3) |
C8—H8B | 0.9700 | C1B—C2B | 1.546 (3) |
C9—C10 | 1.527 (4) | C2B—O2 | 1.208 (3) |
C9—H9A | 0.95 (4) | C2B—O1 | 1.300 (3) |
C9—H9B | 1.00 (3) | O1—H1O | 1.03 (5) |
C1—C6 | 1.387 (4) | ||
C11—S1—C10 | 89.80 (13) | C2—C1—C7 | 121.7 (2) |
C11—N2—C7 | 108.2 (2) | C3—C2—C1 | 120.2 (2) |
C11—N2—H1N | 122 (2) | C3—C2—H2 | 121 (2) |
C7—N2—H1N | 121 (3) | C1—C2—H2 | 118 (2) |
N2—C11—N1 | 114.6 (2) | C9—C10—S1 | 106.10 (19) |
N2—C11—S1 | 131.1 (2) | C9—C10—H10B | 111 (2) |
N1—C11—S1 | 114.23 (18) | S1—C10—H10B | 109 (3) |
N2—C7—C1 | 114.3 (2) | C9—C10—H10A | 115 (2) |
N2—C7—C8 | 101.55 (19) | S1—C10—H10A | 106 (2) |
C1—C7—C8 | 113.3 (2) | H10B—C10—H10A | 110 (3) |
N2—C7—H7 | 109.1 | C4—C3—C2 | 119.0 (3) |
C1—C7—H7 | 109.1 | C4—C3—H3 | 121 (2) |
C8—C7—H7 | 109.1 | C2—C3—H3 | 120 (2) |
C11—N1—C9 | 114.5 (2) | C4—C5—C6 | 118.7 (3) |
C11—N1—C8 | 108.2 (2) | C4—C5—H5 | 126 (3) |
C9—N1—C8 | 127.9 (2) | C6—C5—H5 | 115 (3) |
N1—C8—C7 | 101.46 (19) | C1—C6—C5 | 120.8 (3) |
N1—C8—H8A | 111.5 | C1—C6—H6 | 120 (2) |
C7—C8—H8A | 111.5 | C5—C6—H6 | 119 (2) |
N1—C8—H8B | 111.5 | C5—C4—C3 | 122.0 (3) |
C7—C8—H8B | 111.5 | C5—C4—Br1 | 118.7 (2) |
H8A—C8—H8B | 109.3 | C3—C4—Br1 | 119.3 (2) |
N1—C9—C10 | 104.0 (2) | O4—C1B—O3 | 126.8 (2) |
N1—C9—H9A | 108.6 (19) | O4—C1B—C2B | 118.5 (2) |
C10—C9—H9A | 110.9 (18) | O3—C1B—C2B | 114.69 (19) |
N1—C9—H9B | 108.4 (17) | O2—C2B—O1 | 125.6 (2) |
C10—C9—H9B | 113.1 (18) | O2—C2B—C1B | 121.9 (2) |
H9A—C9—H9B | 111 (3) | O1—C2B—C1B | 112.4 (2) |
C6—C1—C2 | 119.3 (2) | C2B—O1—H1O | 115 (3) |
C6—C1—C7 | 118.9 (2) | ||
C7—N2—C11—N1 | 6.2 (3) | N2—C7—C1—C2 | 39.8 (3) |
C7—N2—C11—S1 | −175.80 (19) | C8—C7—C1—C2 | −75.9 (3) |
C10—S1—C11—N2 | 179.2 (3) | C6—C1—C2—C3 | 0.9 (4) |
C10—S1—C11—N1 | −2.8 (2) | C7—C1—C2—C3 | 177.2 (2) |
C11—N2—C7—C1 | −141.1 (2) | N1—C9—C10—S1 | −32.9 (3) |
C11—N2—C7—C8 | −18.8 (2) | C11—S1—C10—C9 | 21.4 (2) |
N2—C11—N1—C9 | 159.8 (2) | C1—C2—C3—C4 | −1.6 (4) |
S1—C11—N1—C9 | −18.5 (3) | C2—C1—C6—C5 | 0.4 (4) |
N2—C11—N1—C8 | 10.3 (3) | C7—C1—C6—C5 | −176.0 (3) |
S1—C11—N1—C8 | −168.00 (17) | C4—C5—C6—C1 | −0.9 (5) |
C11—N1—C8—C7 | −21.0 (3) | C6—C5—C4—C3 | 0.2 (4) |
C9—N1—C8—C7 | −165.2 (2) | C6—C5—C4—Br1 | 180.0 (2) |
N2—C7—C8—N1 | 23.0 (2) | C2—C3—C4—C5 | 1.1 (4) |
C1—C7—C8—N1 | 146.1 (2) | C2—C3—C4—Br1 | −178.7 (2) |
C11—N1—C9—C10 | 33.8 (3) | O4—C1B—C2B—O2 | 176.5 (2) |
C8—N1—C9—C10 | 176.1 (2) | O3—C1B—C2B—O2 | −2.1 (3) |
N2—C7—C1—C6 | −143.9 (3) | O4—C1B—C2B—O1 | −3.0 (3) |
C8—C7—C1—C6 | 100.4 (3) | O3—C1B—C2B—O1 | 178.4 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1O···O3i | 1.03 (5) | 1.48 (5) | 2.483 (2) | 164 (4) |
N2—H1N···O4 | 0.83 (4) | 1.95 (4) | 2.753 (3) | 163 (4) |
N2—H1N···O1 | 0.83 (4) | 2.37 (4) | 2.879 (3) | 120 (3) |
Symmetry code: (i) x−1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C11H12BrN2S+·C2HO4− |
Mr | 373.22 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 89 |
a, b, c (Å) | 5.615 (1), 8.256 (1), 32.539 (1) |
V (Å3) | 1508.4 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.88 |
Crystal size (mm) | 0.50 × 0.03 × 0.03 |
Data collection | |
Diffractometer | Rigaku R-AXIS RAPID diffractometer |
Absorption correction | Multi-scan (Otwinowski et al., 2003) |
Tmin, Tmax | 0.90, 0.92 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 39658, 4061, 3438 |
Rint | 0.081 |
(sin θ/λ)max (Å−1) | 0.684 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.074, 1.10 |
No. of reflections | 4061 |
No. of parameters | 230 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.67, −0.51 |
Absolute structure | Flack (1983), 1686 Friedel pairs? |
Absolute structure parameter | −0.018 (7) |
Computer programs: HKL-2000 (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), HKL-3000SM (Minor et al., 2006), SHELXL97 (Sheldrick, 2008), HKL-3000SM (Minor et al., 2006), HKL-3000SM (Minor et al., 2006), Mercury (Macrae et al., 2006), ORTEPIII (Burnett & Johnson, 1996) and ORTEP-3 (Farrugia, 1997), HKL-3000SM (Minor et al., 2006).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1O···O3i | 1.03 (5) | 1.48 (5) | 2.483 (2) | 164 (4) |
N2—H1N···O4 | 0.83 (4) | 1.95 (4) | 2.753 (3) | 163 (4) |
N2—H1N···O1 | 0.83 (4) | 2.37 (4) | 2.879 (3) | 120 (3) |
Symmetry code: (i) x−1, y, z. |
Acknowledgements
The authors thank Zbigniew Dauter for helpful discussions. This work was supported by contract No. GI11496 from HKL Research, Inc.
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6-Bromolevamisole (Fig. 1) is a salt of a strong activator of cystic fibrosis conductance regulator (CTFR) chloride channels, including those in human airway epithelial cells. It shows a strong reduction in activity of Protein Phosphatases 2C and 2A, two of the most likely candidates for being a CTFR phosphatase (Luo et al., 2000). It has also been shown to inhibit alkaline phosphatases, including being an uncompetitive inhibitor of an alkaline phosphatase involved in sarcoma (Lee et al., 1975). Furthermore, since inhibitors affect alkaline phosphatase from the white blood cells of mothers of fetuses with Down's syndrome differently, the cation could be involved in screening for it (Denier et al., 2002).
Packing (Fig. 2) is stabilized by hydrogen bonds (Table 1). The oxalate ions form parallel, coplanar, one-dimensional chains via O—H···O hydrogen bonds, with each link in the chain having an N—H···O hydrogen bond from the deprotonated oxygen to the protonated nitrogen (N2) of the 6-bromolevamisole. The bromine also forms a short contact (3.111 Å) with the O3 (-1/2 + x, 1/2 - y, 2 - z) atom.