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Acta Cryst. (2009). E65, o9    [ doi:10.1107/S1600536808039974 ]

Ethyl 3-amino-4H-thieno[2,3-b]pyridine-2-carboxylate

R. Zheng, W. Zhang, L.-T. Yu, S.-Y. Yang and L. Yang

Abstract top

The molecule of the title compound, C10H10N2O2S, is essentially planar, except for the ethyl group, which is twisted away from the carboxyl plane by -90.5 (3)°. In the crystal structure, molecules are linked into a zigzag sheet propagating along the b axis by intermolecular N-H...O and N-H...N hydrogen bonds.

Comment top

Thieno[2,3-b]pyridine derivatives are of great importance owing to their wide biological properties (Litvinov et al.,2005). The title compound is one of the key intermediates in our synthetic investigations of antitumor drugs. We report here its crystal structure.

The thieno[2,3-b]pyridine ring system of the title molecule (Fig.1) is essentially planar. The amino group and the carbonyl group are nearly coplanar with the heterocyclic ring system. The ethyl group is twisted perpendicular to the remaining part of the molecule [C8—O1—C9—C10 = -90.5 (3)°].

In the crystal structure, the molecules are linked into a zigzag sheet propagating along the b axis by intermolecular N—H···O and N—H···N hydrogen bonds (Fig. 2).

Related literature top

For general background, see: Litvinov et al. (2005).

Experimental top

A mixture of 2-chloro-3-cyanopyridine (3.3 g, 0.023 mol), ethyl 2-mercaptoacetate (3.62 g, 0.03 mol), sodium carbonate (2.65 g, 0.025 mol) and anhydrous ethanol (12.0 ml) was heated for 4.5 h under reflux. The reaction mixture was cooled to ambient temperature and added to water (150 ml). The resultant precipitate was stirred for 45 min and then filtered. The filter cake was washed with two portions of water (25 ml) and dried to yield the title compound as a yellow solid (5.032 g, 95.1% yield). Single crystals suitable for X-ray analysis were obtained by slow evaporation of a tetrahydrofuran solution.

Refinement top

H atoms of the amino group were located in a difference map and refined freely. The reminaing H atoms were positioned geometrically (C—H = 0.93–0.97 Å) and refined using a riding model, with Uiso(H) = 1.2–1.5Ueq(C).

Computing details top

Data collection: DIFRAC (Gabe & White, 1993); cell refinement: DIFRAC (Gabe & White, 1993); data reduction: NRCVAX (Gabe et al., 1989); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with displacement ellipsoids drawn at the 30% probability level.
[Figure 2] Fig. 2. A packing diagram of the title compound. Intermolecular hydrogen bonds are shown as dashed open lines.
Ethyl 3-amino-4H-thieno[2,3-b]pyridine-2-carboxylate top
Crystal data top
C10H10N2O2SF(000) = 464
Mr = 222.26Dx = 1.465 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 22 reflections
a = 6.657 (4) Åθ = 4.3–5.7°
b = 13.891 (4) ŵ = 0.30 mm−1
c = 10.902 (4) ÅT = 292 K
β = 91.64 (4)°Block, colourless
V = 1007.8 (8) Å30.60 × 0.46 × 0.42 mm
Z = 4
Data collection top
Enraf–Nonius CAD-4
diffractometer		1515 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.008
graphiteθmax = 25.5°, θmin = 2.4°
ω/2θ scansh = −8→8
Absorption correction: for a sphere
(Dwiggins, 1975)		k = 0→16
Tmin = 0.840, Tmax = 0.884l = −6→13
1978 measured reflections3 standard reflections every 150 reflections
1864 independent reflections intensity decay: 0.6%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.040Hydrogen site location: mixed
wR(F2) = 0.118H atoms treated by a mixture of independent and constrained refinement
S = 1.14 w = 1/[σ2(Fo2) + (0.0562P)2 + 0.4962P]
where P = (Fo2 + 2Fc2)/3
1864 reflections(Δ/σ)max = 0.001
145 parametersΔρmax = 0.26 e Å−3
0 restraintsΔρmin = −0.37 e Å−3
Crystal data top
C10H10N2O2SV = 1007.8 (8) Å3
Mr = 222.26Z = 4
Monoclinic, P21/cMo Kα radiation
a = 6.657 (4) ŵ = 0.30 mm−1
b = 13.891 (4) ÅT = 292 K
c = 10.902 (4) Å0.60 × 0.46 × 0.42 mm
β = 91.64 (4)°
Data collection top
Enraf–Nonius CAD-4
diffractometer		1515 reflections with I > 2σ(I)
Absorption correction: for a sphere
(Dwiggins, 1975)		Rint = 0.008
Tmin = 0.840, Tmax = 0.884θmax = 25.5°
1978 measured reflections3 standard reflections every 150 reflections
1864 independent reflections intensity decay: 0.6%
Refinement top
R[F2 > 2σ(F2)] = 0.040H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.118Δρmax = 0.26 e Å−3
S = 1.14Δρmin = −0.37 e Å−3
1864 reflectionsAbsolute structure: ?
145 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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 (Å2) top
xyzUiso*/Ueq
S10.20405 (9)0.73591 (5)0.16994 (5)0.0405 (2)
O1−0.1351 (2)0.60921 (12)0.17935 (15)0.0442 (4)
O2−0.0551 (3)0.52930 (13)0.35384 (16)0.0487 (5)
N10.5470 (3)0.83735 (15)0.20206 (18)0.0416 (5)
N20.3157 (4)0.58481 (17)0.46991 (19)0.0429 (5)
H1N20.215 (4)0.5502 (18)0.481 (2)0.032 (7)*
H2N20.407 (4)0.593 (2)0.519 (3)0.049 (8)*
C10.7139 (4)0.8539 (2)0.2686 (2)0.0461 (6)
H10.80100.90130.24190.055*
C20.7661 (4)0.8045 (2)0.3756 (2)0.0468 (6)
H20.88510.81920.41840.056*
C30.6422 (4)0.73450 (18)0.4178 (2)0.0394 (6)
H30.67510.70090.48940.047*
C40.4659 (3)0.71448 (16)0.35153 (19)0.0326 (5)
C50.3088 (3)0.64550 (16)0.3736 (2)0.0333 (5)
C60.1607 (3)0.64942 (17)0.2830 (2)0.0348 (5)
C70.4275 (3)0.76841 (17)0.2448 (2)0.0344 (5)
C8−0.0161 (4)0.59041 (17)0.2784 (2)0.0363 (5)
C9−0.3115 (4)0.5493 (2)0.1610 (2)0.0457 (6)
H9A−0.41780.58640.12090.055*
H9B−0.35870.52800.23980.055*
C10−0.2633 (4)0.4637 (2)0.0840 (3)0.0527 (7)
H10A−0.21040.48490.00760.079*
H10B−0.38320.42680.06840.079*
H10C−0.16530.42450.12670.079*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S10.0453 (4)0.0474 (4)0.0286 (3)−0.0085 (3)−0.0057 (2)0.0056 (2)
O10.0454 (10)0.0502 (10)0.0366 (9)−0.0120 (8)−0.0092 (7)0.0033 (8)
O20.0504 (11)0.0543 (11)0.0411 (10)−0.0142 (8)−0.0030 (8)0.0107 (8)
N10.0478 (12)0.0464 (12)0.0307 (10)−0.0095 (9)0.0028 (9)0.0007 (9)
N20.0456 (13)0.0488 (13)0.0338 (11)−0.0089 (11)−0.0060 (10)0.0094 (9)
C10.0465 (14)0.0514 (16)0.0404 (14)−0.0145 (12)0.0050 (11)−0.0037 (12)
C20.0390 (14)0.0640 (17)0.0372 (13)−0.0085 (12)−0.0022 (10)−0.0084 (12)
C30.0399 (13)0.0513 (14)0.0268 (11)−0.0002 (11)−0.0007 (9)−0.0036 (10)
C40.0371 (12)0.0358 (12)0.0250 (11)−0.0001 (9)0.0024 (9)−0.0048 (9)
C50.0380 (12)0.0364 (12)0.0258 (11)0.0013 (9)0.0024 (9)−0.0026 (9)
C60.0396 (13)0.0372 (12)0.0277 (11)−0.0029 (10)−0.0002 (9)0.0008 (9)
C70.0404 (13)0.0387 (12)0.0242 (10)−0.0020 (10)0.0024 (9)−0.0039 (9)
C80.0396 (13)0.0390 (13)0.0303 (12)−0.0014 (10)−0.0012 (10)−0.0023 (10)
C90.0386 (14)0.0545 (16)0.0435 (14)−0.0059 (11)−0.0068 (11)−0.0061 (12)
C100.0517 (16)0.0523 (16)0.0540 (16)−0.0050 (13)0.0001 (13)−0.0078 (13)
Geometric parameters (Å, °) top
S1—C71.736 (3)C2—H20.93
S1—C61.752 (2)C3—C41.389 (3)
O1—C81.347 (3)C3—H30.93
O1—C91.448 (3)C4—C71.401 (3)
O2—C81.215 (3)C4—C51.444 (3)
N1—C11.330 (3)C5—C61.376 (3)
N1—C71.337 (3)C6—C81.434 (3)
N2—C51.346 (3)C9—C101.495 (4)
N2—H1N20.84 (2)C9—H9A0.97
N2—H2N20.81 (3)C9—H9B0.97
C1—C21.389 (4)C10—H10A0.96
C1—H10.93C10—H10B0.96
C2—C31.364 (4)C10—H10C0.96
C7—S1—C690.20 (11)C5—C6—C8125.0 (2)
C8—O1—C9117.08 (19)C5—C6—S1113.77 (17)
C1—N1—C7115.4 (2)C8—C6—S1121.27 (17)
C5—N2—H1N2117.9 (17)N1—C7—C4125.2 (2)
C5—N2—H2N2116 (2)N1—C7—S1122.16 (18)
H1N2—N2—H2N2125 (3)C4—C7—S1112.63 (17)
N1—C1—C2123.9 (2)O2—C8—O1123.1 (2)
N1—C1—H1118.0O2—C8—C6124.5 (2)
C2—C1—H1118.0O1—C8—C6112.4 (2)
C3—C2—C1119.8 (2)O1—C9—C10110.4 (2)
C3—C2—H2120.1O1—C9—H9A109.6
C1—C2—H2120.1C10—C9—H9A109.6
C2—C3—C4118.5 (2)O1—C9—H9B109.6
C2—C3—H3120.7C10—C9—H9B109.6
C4—C3—H3120.7H9A—C9—H9B108.1
C3—C4—C7117.1 (2)C9—C10—H10A109.5
C3—C4—C5130.7 (2)C9—C10—H10B109.5
C7—C4—C5112.2 (2)H10A—C10—H10B109.5
N2—C5—C6126.3 (2)C9—C10—H10C109.5
N2—C5—C4122.5 (2)H10A—C10—H10C109.5
C6—C5—C4111.2 (2)H10B—C10—H10C109.5
C7—N1—C1—C20.0 (4)C1—N1—C7—C40.0 (4)
N1—C1—C2—C3−0.1 (4)C1—N1—C7—S1−179.49 (18)
C1—C2—C3—C40.1 (4)C3—C4—C7—N10.0 (4)
C2—C3—C4—C70.0 (3)C5—C4—C7—N1179.9 (2)
C2—C3—C4—C5−180.0 (2)C3—C4—C7—S1179.53 (17)
C3—C4—C5—N2−1.1 (4)C5—C4—C7—S1−0.5 (2)
C7—C4—C5—N2178.9 (2)C6—S1—C7—N1179.8 (2)
C3—C4—C5—C6−179.5 (2)C6—S1—C7—C40.22 (18)
C7—C4—C5—C60.6 (3)C9—O1—C8—O2−3.2 (3)
N2—C5—C6—C81.9 (4)C9—O1—C8—C6176.0 (2)
C4—C5—C6—C8−179.8 (2)C5—C6—C8—O2−0.6 (4)
N2—C5—C6—S1−178.65 (19)S1—C6—C8—O2−179.94 (19)
C4—C5—C6—S1−0.4 (3)C5—C6—C8—O1−179.8 (2)
C7—S1—C6—C50.12 (19)S1—C6—C8—O10.9 (3)
C7—S1—C6—C8179.6 (2)C8—O1—C9—C10−90.5 (3)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N2—H1N2···O20.84 (2)2.26 (2)2.848 (3)127 (2)
N2—H1N2···O2i0.84 (2)2.38 (3)3.067 (3)139 (2)
N2—H2N2···N1ii0.81 (3)2.38 (3)3.118 (3)152 (3)
Symmetry codes: (i) −x, −y+1, −z+1; (ii) x, −y+3/2, z+1/2.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N2—H1N2···O20.84 (2)2.26 (2)2.848 (3)127 (2)
N2—H1N2···O2i0.84 (2)2.38 (3)3.067 (3)139 (2)
N2—H2N2···N1ii0.81 (3)2.38 (3)3.118 (3)152 (3)
Symmetry codes: (i) −x, −y+1, −z+1; (ii) x, −y+3/2, z+1/2.
references
References top

Dwiggins, C. W. (1975). Acta Cryst. A31, 146–148.

Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.

Gabe, E. J., Le Page, Y., Charland, J.-P., Lee, F. L. & White, P. S. (1989). J. Appl. Cryst. 22, 384–387.

Gabe, E. J. & White, P. S. (1993). DIFRAC. American Crystallographic Association Meeting, Pittsburgh, Abstract PA 104.

Litvinov, V. P., Dotsenko, V. V. & Krivokolysko, S. G. (2005). Russ. Chem. Bull. 54, 864–904.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.