Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803017549/wn6180sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536803017549/wn6180IIsup2.hkl |
CCDC reference: 222887
2-(2-Bromo-1-methylethylidene)malononitrile (0.94 g, 5 mmol) was dissolved in a solution of dioxane (5 ml) and absolute ethanol (20 ml). The stirred solution was cooled to 273 K in an ice-salt bath, and a suspension of NaSH (0.3 g) in 10 ml of absolute ethanol was then added dropwise over a period of 30 min. The resulting reaction mixture was stirred for a further 1 h at room temperature. After removal of the solvent, the residue was filtered on a short Al2O3 column, eluting with hexane-ethyl acetate (7:3). The solvent was removed and the residue crystallized from chloroform to yield (556 mg, 81%) 2-amino-4-methylthiophene-3-carbonitrile (light pink crystals, mp 391–392 K). 1H NMR (200 MHz, CDCl3): δ 5.59 (s, 1H, H5), 4.81 (bs, 2H, NH2), 2.11 (s, 3H, CH3); 13C NMR (50 MHz, CDCl3) δ 162.44, 135.91, 115.52, 105.32, 91.03, 15.53. IR (CHCl3) 3417, 3212, 3097, 2977, 2202, 1627, 1558, 1446, 1300, 1191, 1068, 836.
All H atoms were positioned geometrically and refined in riding mode, with methyl C—H = 0.96 Å, other C—H = 0.93 Å, and N—H = 0.86 Å. For methyl H, Uiso values were set equal to 1.5Ueq of the carrier C atom. For other C—H and N—H, Uiso(H) values were set equal to 1.2Ueq of the carrier atom.
Highly substituted thiophenes form an important part of numerous natural products (Koike et al., 1997) and pharmaceuticals (World Drug Index, 2000). They are often used as novel conducting polymers and isostatic replacements for phenyl groups in medicinal chemistry (Jarvest et al., 1999). The electronic and optical properties of polythiophene and its derivatives have been the subject of many investigations (Roncali, 1997; Ekinci et al., 2002).
The title compound, (II) (Fig. 1), consists of a thiophene ring carrying three subtituents, viz. an amino group, a methyl group and a cyano group. The S—C bond lengths, 1.728 (4) and 1.725 (4) Å, are in good agreement with those in the literature, e.g. 1.734 (2) and 1.721 (3) Å (Han & Choi, 2000), 1.727 (1) and 1.729 (2) Å (Elerman & Elmalı, 1998), and 1.723 (2) and 1.735 (3) Å (Wouters et al., 1997). The C1≡N1 bond distance is 1.153 (4) Å, typical of such a triple bond. This value agrees well with similar bonds reported in the literature, e.g. 1.132 (2) Å (Elerman et al., 1998), 1.130 (5) and 1.142 (5) Å (Çoruh et al., 2002), and 1.148 (2) Å (Boitsov et al., 2002). The molecule of (II) is planar, the maximum deviation from the least-squares plane being 0.0074 (33) Å for atom C4.
A packing diagram of (II) is shown Fig.2. The molecules are stacked such that there are no ring–ring or X—H···π interactions between molecules in the stacks; the distance between planes of molecules in the stacks is 5.671 (7) Å. The crystal structure of (II) is stabilized by two N—H···N intermolecular hydrogen bonds (Table 3 and Fig. 2).
Data collection: COLLECT (Nonius BV, 1997-2000); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997); data reduction: HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 1997); software used to prepare material for publication: SHELXL97 and WinGX (Farrugia, 1999).
C6H6N2S | F(000) = 288 |
Mr = 138.20 | Dx = 1.376 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71069 Å |
Hall symbol: -P 2ybc | Cell parameters from 1153 reflections |
a = 11.900 (5) Å | θ = 1.8–25.2° |
b = 4.130 (5) Å | µ = 0.39 mm−1 |
c = 14.085 (5) Å | T = 293 K |
β = 105.562 (5)° | Block, pink |
V = 666.9 (9) Å3 | 0.20 × 0.15 × 0.10 mm |
Z = 4 |
Nonius KappaCCD diffractometer | 789 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.060 |
Graphite monochromator | θmax = 25.2°, θmin = 1.8° |
Detector resolution: 9.0 pixels mm-1 | h = −13→13 |
φ and ω scans | k = −4→4 |
1849 measured reflections | l = −16→16 |
1135 independent reflections |
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)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.154 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.087P)2] where P = (Fo2 + 2Fc2)/3 |
1135 reflections | (Δ/σ)max < 0.001 |
82 parameters | Δρmax = 0.33 e Å−3 |
0 restraints | Δρmin = −0.31 e Å−3 |
C6H6N2S | V = 666.9 (9) Å3 |
Mr = 138.20 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 11.900 (5) Å | µ = 0.39 mm−1 |
b = 4.130 (5) Å | T = 293 K |
c = 14.085 (5) Å | 0.20 × 0.15 × 0.10 mm |
β = 105.562 (5)° |
Nonius KappaCCD diffractometer | 789 reflections with I > 2σ(I) |
1849 measured reflections | Rint = 0.060 |
1135 independent reflections |
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.154 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.33 e Å−3 |
1135 reflections | Δρmin = −0.31 e Å−3 |
82 parameters |
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All e.s.d.'s are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles |
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 | ||
S1 | 0.22387 (8) | 0.4859 (2) | 0.19442 (6) | 0.0548 (4) | |
N1 | 0.4040 (3) | 0.2476 (9) | 0.5560 (2) | 0.0705 (13) | |
N2 | 0.4211 (2) | 0.1820 (7) | 0.29110 (19) | 0.0569 (10) | |
C1 | 0.3527 (3) | 0.3217 (9) | 0.4774 (2) | 0.0492 (11) | |
C4 | 0.3236 (3) | 0.3380 (8) | 0.2982 (2) | 0.0443 (11) | |
C5 | 0.2886 (3) | 0.4118 (8) | 0.3817 (2) | 0.0438 (10) | |
C6 | 0.1794 (3) | 0.5838 (8) | 0.3609 (2) | 0.0476 (11) | |
C7 | 0.1362 (3) | 0.6384 (9) | 0.2635 (2) | 0.0569 (12) | |
C9 | 0.1231 (3) | 0.6872 (10) | 0.4390 (3) | 0.0666 (14) | |
H2A | 0.47107 | 0.11444 | 0.34343 | 0.0682* | |
H2B | 0.43302 | 0.15043 | 0.23424 | 0.0682* | |
H7 | 0.06649 | 0.74689 | 0.23638 | 0.0682* | |
H9A | 0.17089 | 0.62150 | 0.50243 | 0.0995* | |
H9B | 0.04766 | 0.58798 | 0.42726 | 0.0995* | |
H9C | 0.11467 | 0.91846 | 0.43761 | 0.0995* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0595 (7) | 0.0625 (7) | 0.0379 (5) | 0.0033 (4) | 0.0054 (4) | 0.0032 (4) |
N1 | 0.067 (2) | 0.096 (3) | 0.0456 (18) | 0.0009 (19) | 0.0099 (15) | 0.0109 (17) |
N2 | 0.0566 (18) | 0.069 (2) | 0.0454 (15) | 0.0089 (17) | 0.0140 (13) | 0.0038 (14) |
C1 | 0.0479 (19) | 0.056 (2) | 0.0443 (19) | −0.0050 (17) | 0.0132 (15) | −0.0022 (16) |
C4 | 0.0470 (19) | 0.0425 (19) | 0.0425 (17) | −0.0048 (16) | 0.0105 (14) | 0.0021 (14) |
C5 | 0.0454 (18) | 0.0456 (19) | 0.0388 (17) | −0.0067 (15) | 0.0084 (14) | 0.0013 (14) |
C6 | 0.0461 (19) | 0.049 (2) | 0.0462 (19) | −0.0053 (16) | 0.0096 (15) | −0.0031 (15) |
C7 | 0.051 (2) | 0.059 (2) | 0.055 (2) | 0.0052 (18) | 0.0042 (16) | 0.0027 (18) |
C9 | 0.063 (2) | 0.076 (3) | 0.064 (2) | 0.005 (2) | 0.0226 (18) | −0.006 (2) |
S1—C4 | 1.728 (4) | C5—C6 | 1.440 (5) |
S1—C7 | 1.725 (4) | C6—C9 | 1.496 (5) |
N1—C1 | 1.153 (4) | C6—C7 | 1.349 (4) |
N2—C4 | 1.354 (5) | C7—H7 | 0.9299 |
N2—H2B | 0.8599 | C9—H9A | 0.9605 |
N2—H2A | 0.8600 | C9—H9B | 0.9600 |
C1—C5 | 1.409 (4) | C9—H9C | 0.9600 |
C4—C5 | 1.383 (5) | ||
S1···N1i | 3.401 (5) | C1···H2A | 2.7756 |
S1···H9Aii | 3.0699 | C1···H9A | 2.5976 |
N1···N2iii | 3.117 (6) | C7···H7vii | 2.9042 |
N1···S1iv | 3.401 (5) | H2A···C1 | 2.7756 |
N1···N2iv | 3.276 (5) | H2A···N1iii | 2.3070 |
N2···N1i | 3.276 (5) | H2B···N2v | 2.6863 |
N2···N2v | 3.209 (5) | H2B···N2vi | 2.8798 |
N2···N2vi | 3.209 (5) | H2B···H2Bv | 2.5735 |
N2···N1iii | 3.117 (6) | H2B···H2Bvi | 2.5735 |
N1···H2Aiii | 2.3071 | H2B···N1i | 2.4767 |
N1···H2Biv | 2.4767 | H7···C7viii | 2.9042 |
N2···H2Bvi | 2.6863 | H9A···C1 | 2.5976 |
N2···H2Bv | 2.8798 | H9A···S1ix | 3.0699 |
C4—S1—C7 | 91.95 (15) | C5—C6—C9 | 123.3 (3) |
H2A—N2—H2B | 120.01 | C7—C6—C9 | 125.2 (3) |
C4—N2—H2A | 120.02 | S1—C7—C6 | 112.9 (3) |
C4—N2—H2B | 119.98 | S1—C7—H7 | 123.50 |
N1—C1—C5 | 179.2 (4) | C6—C7—H7 | 123.57 |
S1—C4—N2 | 120.9 (2) | C6—C9—H9A | 109.46 |
S1—C4—C5 | 110.3 (3) | C6—C9—H9B | 109.52 |
N2—C4—C5 | 128.8 (3) | C6—C9—H9C | 109.52 |
C4—C5—C6 | 113.4 (3) | H9A—C9—H9B | 109.43 |
C1—C5—C4 | 123.1 (3) | H9A—C9—H9C | 109.42 |
C1—C5—C6 | 123.5 (3) | H9B—C9—H9C | 109.48 |
C5—C6—C7 | 111.5 (3) | ||
C7—S1—C4—N2 | −179.3 (3) | C1—C5—C6—C7 | −179.7 (3) |
C7—S1—C4—C5 | −0.8 (3) | C1—C5—C6—C9 | 0.5 (5) |
C4—S1—C7—C6 | 0.3 (3) | C4—C5—C6—C9 | 179.4 (3) |
S1—C4—C5—C6 | 1.1 (4) | C4—C5—C6—C7 | −0.8 (4) |
N2—C4—C5—C1 | −1.7 (6) | C9—C6—C7—S1 | 180.0 (3) |
S1—C4—C5—C1 | 179.9 (3) | C5—C6—C7—S1 | 0.2 (4) |
N2—C4—C5—C6 | 179.4 (3) |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) x, −y+3/2, z−1/2; (iii) −x+1, −y, −z+1; (iv) x, −y+1/2, z+1/2; (v) −x+1, y−1/2, −z+1/2; (vi) −x+1, y+1/2, −z+1/2; (vii) −x, y−1/2, −z+1/2; (viii) −x, y+1/2, −z+1/2; (ix) x, −y+3/2, z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2B···N1i | 0.86 | 2.48 | 3.276 (5) | 155 |
N2—H2A···N1iii | 0.86 | 2.31 | 3.117 (6) | 157 |
Symmetry codes: (i) x, −y+1/2, z−1/2; (iii) −x+1, −y, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C6H6N2S |
Mr | 138.20 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 11.900 (5), 4.130 (5), 14.085 (5) |
β (°) | 105.562 (5) |
V (Å3) | 666.9 (9) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.39 |
Crystal size (mm) | 0.20 × 0.15 × 0.10 |
Data collection | |
Diffractometer | Nonius KappaCCD |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1849, 1135, 789 |
Rint | 0.060 |
(sin θ/λ)max (Å−1) | 0.599 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.154, 1.00 |
No. of reflections | 1135 |
No. of parameters | 82 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.33, −0.31 |
Computer programs: COLLECT (Nonius BV, 1997-2000), HKL SCALEPACK (Otwinowski & Minor 1997), HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997) and PLATON (Spek, 1997), SHELXL97 and WinGX (Farrugia, 1999).
S1—C4 | 1.728 (4) | N1—C1 | 1.153 (4) |
S1—C7 | 1.725 (4) | N2—C4 | 1.354 (5) |
S1···N1i | 3.401 (5) | N1···S1iii | 3.401 (5) |
N1···N2ii | 3.117 (6) | ||
C4—S1—C7 | 91.95 (15) | S1—C4—C5 | 110.3 (3) |
N1—C1—C5 | 179.2 (4) | N2—C4—C5 | 128.8 (3) |
S1—C4—N2 | 120.9 (2) | S1—C7—C6 | 112.9 (3) |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) −x+1, −y, −z+1; (iii) x, −y+1/2, z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2B···N1i | 0.86 | 2.48 | 3.276 (5) | 155 |
N2—H2A···N1ii | 0.86 | 2.31 | 3.117 (6) | 157 |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) −x+1, −y, −z+1. |
Highly substituted thiophenes form an important part of numerous natural products (Koike et al., 1997) and pharmaceuticals (World Drug Index, 2000). They are often used as novel conducting polymers and isostatic replacements for phenyl groups in medicinal chemistry (Jarvest et al., 1999). The electronic and optical properties of polythiophene and its derivatives have been the subject of many investigations (Roncali, 1997; Ekinci et al., 2002).
The title compound, (II) (Fig. 1), consists of a thiophene ring carrying three subtituents, viz. an amino group, a methyl group and a cyano group. The S—C bond lengths, 1.728 (4) and 1.725 (4) Å, are in good agreement with those in the literature, e.g. 1.734 (2) and 1.721 (3) Å (Han & Choi, 2000), 1.727 (1) and 1.729 (2) Å (Elerman & Elmalı, 1998), and 1.723 (2) and 1.735 (3) Å (Wouters et al., 1997). The C1≡N1 bond distance is 1.153 (4) Å, typical of such a triple bond. This value agrees well with similar bonds reported in the literature, e.g. 1.132 (2) Å (Elerman et al., 1998), 1.130 (5) and 1.142 (5) Å (Çoruh et al., 2002), and 1.148 (2) Å (Boitsov et al., 2002). The molecule of (II) is planar, the maximum deviation from the least-squares plane being 0.0074 (33) Å for atom C4.
A packing diagram of (II) is shown Fig.2. The molecules are stacked such that there are no ring–ring or X—H···π interactions between molecules in the stacks; the distance between planes of molecules in the stacks is 5.671 (7) Å. The crystal structure of (II) is stabilized by two N—H···N intermolecular hydrogen bonds (Table 3 and Fig. 2).