organic compounds
5-Bromo-1H-thieno[2,3-d]imidazole
aPfizer Global Research and Development, La Jolla Labs, 10770 Science Center Drive, San Diego, CA 92121, USA, and bDepartment of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
*Correspondence e-mail: alex.yanovsky@pfizer.com
The 5H3BrN2S, shows that bromination of 1H-thieno[2,3-d]imidazole with N-bromosuccinimide in acetonitrile occurs at position 5 of the bicyclic system. The molecule is almost planar, with a mean deviation of 0.015 Å from the least-squares plane through all the non-H atoms. In the crystal, N—H⋯N hydrogen bonds link the molecules into infinite C(4) chains running along [101].
of the title compound, CRelated literature
For a related structure involving the thieno[2,3-d]imidazole fragment, see: Busetti et al. (1989).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2007); cell SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536810027224/hb5547sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810027224/hb5547Isup2.hkl
To a solution of 1H-thieno[2,3-d]imidazole (16 mg, 0.13 mmol) in 0.75 ml of acetonitrile at 0°C was added dropwise N-bromosuccinimide (21 mg, 0.12 mmol) in 0.25 ml of acetonitrile. The reaction mixture was stirred at 0°C for 0.5 hr. The reaction mixture was diluted with 10 ml of 1 N NaOH, and the aqueous layer was extracted with EtOAc (3 × 15 ml). The organic layers were combined, dried over Na2SO4, filtered and concentrated. The product was purified by flash
(silica gel, 0–70% EtOAc/heptane) to give 22 mg (81%) 5-bromo-1H-thieno[2,3-d]imidazole as an off white solid.Light brown needles of (I) were grown by slow evaporation of a 20/20/60 methanol/dichloromethane/toluene solution
All H atoms were placed in geometrically calculated positions (N—H 0.88 Å, C—H 0.95 Å) and included in the
in the riding motion approximation. The Uiso(H) were set to 1.2Ueq of the carrying atom. The highest residual peak of 1.41 e/Å3 is located at 0.91 Å from the Br1 atom.Bromination of 1H-thieno[2,3-d]imidazole by bromosuccinimide in acetonitrile may occur either at position 2,5 or 6. The present X-ray study showed that substitution occurs in fact at position 5; the molecular structure of the title compound, representing the major product of bromination is shown in Fig. 1.
The molecule of the title compound is planar; maximum deviation of the Br1 atom from the mean plane of all non-H atoms of the molecule is equal to 0.029 (3) Å. To the best of our knowledge, this is the first structural study of thieno[2,3-d]imidazole derivative with the isolated bicyclic system. In the only closely related molecule, studied by the single-crystal X-ray diffraction earlier (Busetti et al., 1989), the thieno[2,3-d]imidazole system is fused with the benzene ring, thus forming a tricyclic molecule. The geometry of the thienoimidazole fragment of the tricyclic molecule is very similar to that of the title compound.
There is one symmetry independent intermolecular H-bond in the structure (Table 1), which is responsible for the formation of infinite chains of molecules running along the [101] direction of the crystal (Fig. 2).
For a related structure involving the thieno[2,3-d]imidazole fragment, see: Busetti et al. (1989).
Data collection: APEX2 (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C5H3BrN2S | F(000) = 392 |
Mr = 203.06 | Dx = 2.153 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 4198 reflections |
a = 3.8917 (11) Å | θ = 2.4–27.4° |
b = 17.118 (5) Å | µ = 6.79 mm−1 |
c = 9.405 (3) Å | T = 100 K |
β = 91.359 (3)° | Needle, light brown |
V = 626.4 (3) Å3 | 0.32 × 0.18 × 0.09 mm |
Z = 4 |
Bruker APEX CCD diffractometer | 1441 independent reflections |
Radiation source: fine-focus sealed tube | 1270 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.043 |
φ and ω scans | θmax = 28.2°, θmin = 2.4° |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | h = −5→5 |
Tmin = 0.220, Tmax = 0.580 | k = −22→21 |
9691 measured reflections | l = −11→12 |
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)] = 0.036 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.098 | H-atom parameters constrained |
S = 1.08 | w = 1/[σ2(Fo2) + (0.0585P)2 + 0.9841P] where P = (Fo2 + 2Fc2)/3 |
1441 reflections | (Δ/σ)max < 0.001 |
83 parameters | Δρmax = 1.41 e Å−3 |
0 restraints | Δρmin = −0.81 e Å−3 |
C5H3BrN2S | V = 626.4 (3) Å3 |
Mr = 203.06 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 3.8917 (11) Å | µ = 6.79 mm−1 |
b = 17.118 (5) Å | T = 100 K |
c = 9.405 (3) Å | 0.32 × 0.18 × 0.09 mm |
β = 91.359 (3)° |
Bruker APEX CCD diffractometer | 1441 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2001) | 1270 reflections with I > 2σ(I) |
Tmin = 0.220, Tmax = 0.580 | Rint = 0.043 |
9691 measured reflections |
R[F2 > 2σ(F2)] = 0.036 | 0 restraints |
wR(F2) = 0.098 | H-atom parameters constrained |
S = 1.08 | Δρmax = 1.41 e Å−3 |
1441 reflections | Δρmin = −0.81 e Å−3 |
83 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.78267 (9) | 0.43247 (2) | 0.25169 (4) | 0.01969 (18) | |
S1 | 0.4398 (2) | 0.58614 (6) | 0.13967 (10) | 0.0204 (3) | |
N1 | 0.4603 (8) | 0.71893 (18) | 0.4614 (3) | 0.0186 (7) | |
H1N | 0.5141 | 0.7276 | 0.5515 | 0.022* | |
N2 | 0.2480 (8) | 0.7397 (2) | 0.2389 (3) | 0.0212 (7) | |
C1 | 0.6366 (9) | 0.5359 (2) | 0.2806 (4) | 0.0178 (7) | |
C2 | 0.6719 (9) | 0.5760 (2) | 0.4074 (4) | 0.0159 (7) | |
H2 | 0.7747 | 0.5568 | 0.4932 | 0.019* | |
C3 | 0.5239 (9) | 0.6521 (2) | 0.3853 (4) | 0.0169 (7) | |
C4 | 0.3908 (9) | 0.6662 (2) | 0.2503 (4) | 0.0168 (7) | |
C5 | 0.2976 (10) | 0.7690 (2) | 0.3697 (4) | 0.0206 (8) | |
H5 | 0.2262 | 0.8200 | 0.3960 | 0.025* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0235 (2) | 0.0164 (3) | 0.0190 (3) | 0.00184 (12) | −0.00180 (14) | −0.00335 (13) |
S1 | 0.0251 (5) | 0.0207 (5) | 0.0153 (5) | 0.0007 (3) | −0.0021 (4) | −0.0008 (4) |
N1 | 0.0240 (16) | 0.0179 (16) | 0.0140 (16) | −0.0007 (12) | −0.0001 (12) | −0.0003 (13) |
N2 | 0.0225 (16) | 0.0183 (18) | 0.0227 (18) | −0.0007 (11) | −0.0005 (13) | 0.0031 (13) |
C1 | 0.0189 (17) | 0.0149 (18) | 0.0196 (19) | −0.0004 (13) | 0.0011 (13) | −0.0008 (15) |
C2 | 0.0201 (17) | 0.0141 (17) | 0.0137 (18) | −0.0012 (13) | 0.0033 (13) | 0.0018 (13) |
C3 | 0.0195 (17) | 0.0171 (18) | 0.0140 (18) | −0.0024 (13) | −0.0009 (13) | 0.0002 (14) |
C4 | 0.0204 (17) | 0.0140 (17) | 0.0161 (19) | −0.0002 (14) | −0.0006 (13) | 0.0018 (14) |
C5 | 0.0258 (19) | 0.0154 (18) | 0.021 (2) | 0.0007 (14) | 0.0012 (15) | 0.0020 (15) |
Br1—C1 | 1.882 (4) | N2—C4 | 1.378 (5) |
S1—C4 | 1.734 (4) | C1—C2 | 1.379 (5) |
S1—C1 | 1.742 (4) | C2—C3 | 1.438 (5) |
N1—C5 | 1.362 (5) | C2—H2 | 0.9500 |
N1—C3 | 1.375 (5) | C3—C4 | 1.381 (5) |
N1—H1N | 0.8800 | C5—H5 | 0.9500 |
N2—C5 | 1.338 (5) | ||
C4—S1—C1 | 89.20 (18) | C3—C2—H2 | 126.4 |
C5—N1—C3 | 106.3 (3) | N1—C3—C4 | 105.3 (3) |
C5—N1—H1N | 126.8 | N1—C3—C2 | 139.1 (3) |
C3—N1—H1N | 126.8 | C4—C3—C2 | 115.6 (3) |
C5—N2—C4 | 102.8 (3) | N2—C4—C3 | 111.9 (3) |
C2—C1—S1 | 116.5 (3) | N2—C4—S1 | 136.4 (3) |
C2—C1—Br1 | 124.6 (3) | C3—C4—S1 | 111.6 (3) |
S1—C1—Br1 | 118.9 (2) | N2—C5—N1 | 113.6 (3) |
C1—C2—C3 | 107.1 (3) | N2—C5—H5 | 123.2 |
C1—C2—H2 | 126.4 | N1—C5—H5 | 123.2 |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···N2i | 0.88 | 2.04 | 2.903 (4) | 165 |
Symmetry code: (i) x+1/2, −y+3/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C5H3BrN2S |
Mr | 203.06 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 100 |
a, b, c (Å) | 3.8917 (11), 17.118 (5), 9.405 (3) |
β (°) | 91.359 (3) |
V (Å3) | 626.4 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 6.79 |
Crystal size (mm) | 0.32 × 0.18 × 0.09 |
Data collection | |
Diffractometer | Bruker APEX CCD |
Absorption correction | Multi-scan (SADABS; Bruker, 2001) |
Tmin, Tmax | 0.220, 0.580 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9691, 1441, 1270 |
Rint | 0.043 |
(sin θ/λ)max (Å−1) | 0.665 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.036, 0.098, 1.08 |
No. of reflections | 1441 |
No. of parameters | 83 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 1.41, −0.81 |
Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···N2i | 0.88 | 2.04 | 2.903 (4) | 165 |
Symmetry code: (i) x+1/2, −y+3/2, z+1/2. |
References
Bruker (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Busetti, V., Guerrera, F., Siracusa, M. A., Ajo, D. & De Zuane, F. (1989). Z. Kristallogr. 187, 187–191. CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
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Bromination of 1H-thieno[2,3-d]imidazole by bromosuccinimide in acetonitrile may occur either at position 2,5 or 6. The present X-ray study showed that substitution occurs in fact at position 5; the molecular structure of the title compound, representing the major product of bromination is shown in Fig. 1.
The molecule of the title compound is planar; maximum deviation of the Br1 atom from the mean plane of all non-H atoms of the molecule is equal to 0.029 (3) Å. To the best of our knowledge, this is the first structural study of thieno[2,3-d]imidazole derivative with the isolated bicyclic system. In the only closely related molecule, studied by the single-crystal X-ray diffraction earlier (Busetti et al., 1989), the thieno[2,3-d]imidazole system is fused with the benzene ring, thus forming a tricyclic molecule. The geometry of the thienoimidazole fragment of the tricyclic molecule is very similar to that of the title compound.
There is one symmetry independent intermolecular H-bond in the structure (Table 1), which is responsible for the formation of infinite chains of molecules running along the [101] direction of the crystal (Fig. 2).