Diethyl 2-amino-5-[(E)-(furan-2-yl­methyl­idene)amino]­thio­phene-3,4-di­carboxyl­ate

doi:10.1107/S1600536810043746

Acta Crystallogr Sect E Struct Rep Online. 2010 November 1; 66(Pt 11): o3027.

Published online 2010 October 31. doi: 10.1107/S1600536810043746

PMCID: PMC3009046

Diethyl 2-amino-5-[(E)-(furan-2-ylmethylidene)amino]thiophene-3,4-dicarboxylate

Stéphane Dufresne^a and W. G. Skene^a^*

^aDepartment of Chemistry, University of Montreal, CP 6128, succ. Centre-ville, Montréal, Québec, Canada, H3C 3J7

Correspondence e-mail: w.skene/at/umontreal.ca

Received October 21, 2010; Accepted October 26, 2010.

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Abstract

In the crystal structure of the title compound, C₁₅H₁₆N₂O₅S, the azomethine adopts the E configuration. The two heterocyclic rings adopt an antiperiplanar orientation. The mean planes of the thiophene and furan rings are twisted by 2.51 (4)°. The crystal structure exhibits intermolecular N—H (...)

O hydrogen bonding. π–π stacking is also observed, the centroid-to-centroid distance being 3.770 (4) Å.

Related literature

For general background, see: Dufresne & Skene (2008

). For a related crystal structure, see: Skene et al. (2006

)

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Object name is e-66-o3027-scheme1.jpg Object name is e-66-o3027-scheme1.jpg

Experimental

Crystal data

C₁₅H₁₆N₂O₅S
M _r = 336.36
Monoclinic,
a = 9.3452 (19) Å
b = 14.635 (3) Å
c = 11.343 (2) Å
β = 99.73 (3)°
V = 1529.0 (5) Å³
Z = 4
Cu Kα radiation
μ = 2.14 mm⁻¹
T = 123 K
0.14 × 0.10 × 0.04 mm

Data collection

Bruker SMART 6000 diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T _min = 0.728, T _max = 0.920
6320 measured reflections
3005 independent reflections
2475 reflections with I > 2σ(I)
R _int = 0.036

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.102
S = 1.03
3005 reflections
210 parameters
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: SMART (Bruker, 2003

); cell refinement: SAINT (Bruker, 2004

); 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

) and ORTEP-3 (Farrugia, 1997

); software used to prepare material for publication: UdMX (Marris, 2004

Table 1

Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810043746/wn2415sup1.cif

Click here to view.^{(19K, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810043746/wn2415Isup2.hkl

Click here to view.^{(147K, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

NSERC Canada is thanked for DG and RTI grants allowing this work to be performed, in addition to CFI for additional equipment funding. SD also thanks NSERC for a graduate scholarship. WGS also acknowledges both the Alexander von Humboldt Foundation and the RSC for J. W. T. Jones Travelling fellowships, allowing the completion of this manuscript.

supplementary crystallographic information

Comment

During the course of our ongoing conjugated azomethine research, we prepared the title compound. The X-ray crystallographic analysis not only confirmed the structure (Fig. 1), but that the energetically stable E isomer was formed. Neither solvent nor counter-ions were found in the structure.

The heterocyclic rings were found not to be coplanar; the angle between the heterocyclic mean planes is 2.51 (4)°. This angle is less than that in a previously reported azomethine thiophene system, whose angle is 7.25 (11)° (Skene et al., 2006).

A major point of interest is the azomethine bond. The bond lengths for N2—C4, N2—C5 and C5—C6 are 1.382 (2), 1.289 (2) and 1.420 (2) Å, respectively. These are similar to the related azomethine thiophene compound (Skene et al., 2006), whose homologous lengths are 1.381 (3), 1.283 (3) and 1.426 (3) Å.

Fig. 2 shows that two different hydrogen bonds occur in the crystal structure, viz. N1—H1A···O2ⁱⁱⁱ and N1—H1B···O4ⁱⁱ. The D—H···A angles are 135° and 122° and distances of 2.880 (3) Å and 3.059 (3) Å were measured between the nitrogen and oxygens (Table 1). Dimerization of two molecules occurs via H-bonding between N1—H1A···O2ⁱⁱⁱ. Additionally, π-stacking takes place between two different molecules, at [x, y, z] and [1 - x, -y, 1 - z]. Fig. 3 shows the interactions, with the distance between the planes being 3.440 (4) Å. The centroid···centroid distance between the two rings is 3.770 (4) Å.

Experimental

2-Furaldehyde (37 mg, 0.39 mmol) and 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester (100 mg, 0.39 mmol) were mixed in anhydrous 2-propanol with a catalytic amount of TFA and refluxed for 12 h. The reaction was then purified by flash chromatography to afford the title compound as a brownish yellow solid (110 mg, 85%). Single crystals were obtained by slow evaporation of an acetone solution.

Figures

Fig. 1.

ORTEP-3 (Farrugia, 1997) representation of the molecular structure, with the numbering scheme adopted. Displacement ellipsoids are drawn at the 30% probability level. H atoms are shown as spheres of arbitrary radius.

Fig. 2.

Supramolecular structure showing the intermolecular hydrogen bonding (dashed lines). [Symmetry codes: (i) 1/2 - x, 1/2 + y, 1.5 - z; (ii) 1/2 - x, -1/2 + y, 1.5 - z; (iii) -x, -y, 2 - z.]

Fig. 3.

The three-dimensional network demonstrating the π-stacking (dashed lines) in the crystal structure.

Crystal data

C₁₅H₁₆N₂O₅S	F(000) = 704
M_r = 336.36	D_x = 1.461 Mg m⁻³
Monoclinic, P2₁/n	Melting point: 425(2) K
Hall symbol: -P 2yn	Cu Kα radiation, λ = 1.54178 Å
a = 9.3452 (19) Å	Cell parameters from 3360 reflections
b = 14.635 (3) Å	θ = 5.0–38.8°
c = 11.343 (2) Å	µ = 2.14 mm⁻¹
β = 99.73 (3)°	T = 123 K
V = 1529.0 (5) Å³	Block, yellow
Z = 4	0.14 × 0.10 × 0.04 mm

Data collection

Bruker SMART 6000 diffractometer	3005 independent reflections
Radiation source: rotating anode	2475 reflections with I > 2σ(I)
Montel 200 optics	R_int = 0.036
Detector resolution: 5.5 pixels mm^-1	θ_max = 72.3°, θ_min = 5.0°
ω scans	h = −11→11
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −17→18
T_min = 0.728, T_max = 0.920	l = −13→13
6320 measured reflections

Refinement

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.102	H-atom parameters constrained
S = 1.03	w = 1/[σ²(F_o²) + (0.0643P)²] where P = (F_o² + 2F_c²)/3
3005 reflections	(Δ/σ)_max = 0.001
210 parameters	Δρ_max = 0.29 e Å⁻³
0 restraints	Δρ_min = −0.34 e Å⁻³

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 (Å²)

	x	y	z	U_iso*/U_eq
S1	0.15876 (5)	0.01058 (3)	0.62132 (4)	0.02153 (13)
O3	0.26457 (13)	0.20322 (8)	0.97617 (10)	0.0216 (3)
O5	0.53448 (13)	0.16250 (8)	0.86520 (11)	0.0229 (3)
O1	0.53601 (14)	0.14839 (10)	0.36188 (11)	0.0299 (3)
O4	0.42258 (13)	0.28091 (8)	0.76310 (11)	0.0261 (3)
O2	0.11370 (14)	0.08821 (9)	1.00209 (11)	0.0280 (3)
N2	0.37833 (15)	0.11513 (10)	0.55344 (12)	0.0201 (3)
N1	0.01952 (16)	−0.02136 (10)	0.80267 (14)	0.0247 (3)
H1A	−0.0029	−0.0108	0.8737	0.030*
H1B	−0.0274	−0.0637	0.7563	0.030*
C13	0.42543 (18)	0.20165 (12)	0.79259 (14)	0.0180 (3)
C2	0.21155 (17)	0.09610 (11)	0.82328 (15)	0.0177 (3)
C4	0.29499 (18)	0.09523 (12)	0.63985 (15)	0.0194 (4)
C10	0.19189 (18)	0.12672 (12)	0.94126 (15)	0.0192 (4)
C3	0.30893 (17)	0.13360 (12)	0.75044 (14)	0.0175 (3)
C14	0.65332 (19)	0.22184 (13)	0.91629 (17)	0.0274 (4)
H14A	0.6231	0.2619	0.9780	0.033*
H14B	0.6830	0.2608	0.8533	0.033*
C1	0.12570 (18)	0.02730 (12)	0.76478 (15)	0.0191 (4)
C6	0.42538 (19)	0.08612 (12)	0.35493 (16)	0.0218 (4)
C5	0.35120 (19)	0.07232 (12)	0.45285 (15)	0.0225 (4)
H5	0.2757	0.0281	0.4435	0.027*
C11	0.2356 (2)	0.24369 (13)	1.08714 (15)	0.0259 (4)
H11A	0.2526	0.1984	1.1528	0.031*
H11B	0.1335	0.2646	1.0776	0.031*
C8	0.5077 (2)	0.08255 (14)	0.18213 (16)	0.0284 (4)
H8	0.5204	0.0675	0.1031	0.034*
C7	0.4049 (2)	0.04441 (13)	0.24649 (16)	0.0272 (4)
H7	0.3351	−0.0014	0.2191	0.033*
C9	0.5836 (2)	0.14410 (15)	0.25473 (17)	0.0316 (5)
H9	0.6604	0.1800	0.2343	0.038*
C15	0.7766 (2)	0.16205 (14)	0.97085 (18)	0.0320 (4)
H15A	0.7455	0.1231	1.0321	0.048*
H15B	0.8583	0.2002	1.0075	0.048*
H15C	0.8068	0.1237	0.9087	0.048*
C12	0.3367 (2)	0.32281 (13)	1.11445 (17)	0.0351 (5)
H12A	0.4372	0.3007	1.1284	0.053*
H12B	0.3167	0.3543	1.1862	0.053*
H12C	0.3227	0.3653	1.0467	0.053*

Atomic displacement parameters (Å²)

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0226 (2)	0.0245 (2)	0.0170 (2)	−0.00387 (17)	0.00208 (16)	−0.00373 (16)
O3	0.0288 (7)	0.0215 (6)	0.0158 (6)	−0.0027 (5)	0.0072 (5)	−0.0041 (5)
O5	0.0206 (6)	0.0213 (6)	0.0245 (7)	−0.0023 (5)	−0.0025 (5)	−0.0003 (5)
O1	0.0275 (7)	0.0373 (8)	0.0254 (7)	−0.0063 (6)	0.0062 (6)	−0.0053 (6)
O4	0.0286 (7)	0.0206 (7)	0.0278 (7)	−0.0032 (5)	0.0013 (5)	0.0036 (5)
O2	0.0310 (7)	0.0308 (7)	0.0253 (7)	−0.0070 (6)	0.0134 (6)	−0.0019 (6)
N2	0.0221 (7)	0.0234 (8)	0.0148 (7)	0.0023 (6)	0.0036 (6)	0.0009 (6)
N1	0.0242 (8)	0.0269 (8)	0.0239 (8)	−0.0083 (6)	0.0069 (6)	−0.0038 (6)
C13	0.0205 (8)	0.0216 (9)	0.0131 (8)	0.0010 (6)	0.0060 (6)	−0.0011 (6)
C2	0.0171 (8)	0.0183 (8)	0.0175 (8)	0.0003 (6)	0.0028 (6)	0.0004 (6)
C4	0.0191 (8)	0.0222 (9)	0.0170 (8)	0.0003 (7)	0.0032 (7)	0.0008 (7)
C10	0.0178 (8)	0.0213 (9)	0.0184 (8)	0.0015 (6)	0.0025 (7)	0.0006 (7)
C3	0.0174 (8)	0.0184 (8)	0.0168 (8)	0.0013 (6)	0.0032 (6)	0.0017 (6)
C14	0.0222 (9)	0.0273 (10)	0.0309 (10)	−0.0057 (7)	−0.0011 (8)	−0.0059 (8)
C1	0.0181 (8)	0.0200 (8)	0.0185 (8)	0.0023 (6)	0.0013 (7)	0.0006 (7)
C6	0.0235 (8)	0.0226 (9)	0.0188 (8)	0.0000 (7)	0.0022 (7)	0.0008 (7)
C5	0.0267 (9)	0.0222 (9)	0.0188 (9)	−0.0013 (7)	0.0041 (7)	0.0005 (7)
C11	0.0380 (10)	0.0256 (9)	0.0154 (8)	0.0023 (8)	0.0080 (8)	−0.0038 (7)
C8	0.0314 (10)	0.0375 (11)	0.0174 (9)	0.0075 (8)	0.0076 (8)	0.0002 (8)
C7	0.0365 (10)	0.0259 (10)	0.0198 (9)	−0.0008 (8)	0.0061 (8)	−0.0038 (7)
C9	0.0266 (10)	0.0429 (12)	0.0278 (10)	−0.0014 (8)	0.0115 (8)	0.0052 (9)
C15	0.0236 (9)	0.0391 (11)	0.0303 (10)	0.0003 (8)	−0.0043 (8)	−0.0037 (9)
C12	0.0578 (14)	0.0241 (10)	0.0235 (10)	−0.0043 (10)	0.0078 (9)	−0.0049 (8)

Geometric parameters (Å, °)

S1—C1	1.7242 (18)	C14—C15	1.495 (3)
S1—C4	1.7633 (18)	C14—H14A	0.99
O3—C10	1.334 (2)	C14—H14B	0.99
O3—C11	1.4573 (19)	C6—C7	1.357 (2)
O5—C13	1.3272 (19)	C6—C5	1.420 (2)
O5—C14	1.451 (2)	C5—H5	0.95
O1—C9	1.364 (2)	C11—C12	1.494 (3)
O1—C6	1.370 (2)	C11—H11A	0.99
O4—C13	1.206 (2)	C11—H11B	0.99
O2—C10	1.224 (2)	C8—C9	1.340 (3)
N2—C5	1.289 (2)	C8—C7	1.416 (3)
N2—C4	1.382 (2)	C8—H8	0.95
N1—C1	1.349 (2)	C7—H7	0.95
N1—H1A	0.88	C9—H9	0.95
N1—H1B	0.88	C15—H15A	0.98
C13—C3	1.493 (2)	C15—H15B	0.98
C2—C1	1.385 (2)	C15—H15C	0.98
C2—C3	1.437 (2)	C12—H12A	0.98
C2—C10	1.452 (2)	C12—H12B	0.98
C4—C3	1.360 (2)	C12—H12C	0.98

C1—S1—C4	91.65 (8)	C7—C6—C5	129.21 (18)
C10—O3—C11	115.96 (13)	O1—C6—C5	120.86 (16)
C13—O5—C14	116.42 (14)	N2—C5—C6	125.07 (17)
C9—O1—C6	105.92 (15)	N2—C5—H5	117.5
C5—N2—C4	118.38 (15)	C6—C5—H5	117.5
C1—N1—H1A	120	O3—C11—C12	106.90 (15)
C1—N1—H1B	120	O3—C11—H11A	110.3
H1A—N1—H1B	120	C12—C11—H11A	110.3
O4—C13—O5	124.46 (16)	O3—C11—H11B	110.3
O4—C13—C3	124.88 (16)	C12—C11—H11B	110.3
O5—C13—C3	110.65 (14)	H11A—C11—H11B	108.6
C1—C2—C3	111.96 (15)	C9—C8—C7	106.42 (17)
C1—C2—C10	120.84 (15)	C9—C8—H8	126.8
C3—C2—C10	127.08 (15)	C7—C8—H8	126.8
C3—C4—N2	126.11 (16)	C6—C7—C8	106.60 (17)
C3—C4—S1	110.77 (13)	C6—C7—H7	126.7
N2—C4—S1	123.06 (13)	C8—C7—H7	126.7
O2—C10—O3	122.79 (16)	C8—C9—O1	111.14 (17)
O2—C10—C2	123.91 (16)	C8—C9—H9	124.4
O3—C10—C2	113.27 (14)	O1—C9—H9	124.4
C4—C3—C2	113.65 (15)	C14—C15—H15A	109.5
C4—C3—C13	121.43 (15)	C14—C15—H15B	109.5
C2—C3—C13	124.67 (15)	H15A—C15—H15B	109.5
O5—C14—C15	107.41 (15)	C14—C15—H15C	109.5
O5—C14—H14A	110.2	H15A—C15—H15C	109.5
C15—C14—H14A	110.2	H15B—C15—H15C	109.5
O5—C14—H14B	110.2	C11—C12—H12A	109.5
C15—C14—H14B	110.2	C11—C12—H12B	109.5
H14A—C14—H14B	108.5	H12A—C12—H12B	109.5
N1—C1—C2	128.96 (16)	C11—C12—H12C	109.5
N1—C1—S1	118.97 (13)	H12A—C12—H12C	109.5
C2—C1—S1	111.94 (13)	H12B—C12—H12C	109.5
C7—C6—O1	109.92 (16)

C14—O5—C13—O4	3.5 (2)	O5—C13—C3—C4	−101.12 (18)
C14—O5—C13—C3	−177.89 (14)	O4—C13—C3—C2	−108.6 (2)
C5—N2—C4—C3	179.86 (17)	O5—C13—C3—C2	72.8 (2)
C5—N2—C4—S1	2.9 (2)	C13—O5—C14—C15	−167.31 (15)
C1—S1—C4—C3	−1.07 (14)	C3—C2—C1—N1	−177.66 (17)
C1—S1—C4—N2	176.35 (15)	C10—C2—C1—N1	−1.3 (3)
C11—O3—C10—O2	−5.4 (2)	C3—C2—C1—S1	−1.82 (18)
C11—O3—C10—C2	172.78 (14)	C10—C2—C1—S1	174.49 (12)
C1—C2—C10—O2	9.1 (3)	C4—S1—C1—N1	177.96 (14)
C3—C2—C10—O2	−175.17 (17)	C4—S1—C1—C2	1.66 (13)
C1—C2—C10—O3	−169.01 (15)	C9—O1—C6—C7	0.0 (2)
C3—C2—C10—O3	6.7 (2)	C9—O1—C6—C5	179.52 (17)
N2—C4—C3—C2	−177.09 (15)	C4—N2—C5—C6	178.96 (16)
S1—C4—C3—C2	0.22 (19)	C7—C6—C5—N2	179.79 (19)
N2—C4—C3—C13	−2.6 (3)	O1—C6—C5—N2	0.3 (3)
S1—C4—C3—C13	174.76 (12)	C10—O3—C11—C12	175.14 (15)
C1—C2—C3—C4	1.0 (2)	O1—C6—C7—C8	−0.1 (2)
C10—C2—C3—C4	−175.00 (16)	C5—C6—C7—C8	−179.58 (18)
C1—C2—C3—C13	−173.30 (15)	C9—C8—C7—C6	0.2 (2)
C10—C2—C3—C13	10.7 (3)	C7—C8—C9—O1	−0.2 (2)
O4—C13—C3—C4	77.5 (2)	C6—O1—C9—C8	0.1 (2)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2ⁱ	0.88	2.20	2.889 (2)	135
N1—H1B···O4ⁱⁱ	0.88	2.50	3.059 (3)	122

Symmetry codes: (i) −x, −y, −z+2; (ii) −x+1/2, y−1/2, −z+3/2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WN2415).

References

Bruker (2003). SMART. Bruker AXS Inc., Madison, Wisconsin, USA.
Bruker (2004). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Dufresne, S. & Skene, W. G. (2008). J. Org. Chem.73, 3859–3866. [PubMed]
Farrugia, L. J. (1997). J. Appl. Cryst.30, 565.
Marris, T. (2004). UdMX Université de Montréal, Canada.
Sheldrick, G. M. (1996). SADABS University of Göttingen, Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
Skene, W. G., Dufresne, S., Trefz, T. & Simard, M. (2006). Acta Cryst. E62, o2382–o2384.

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