Synthesis, characterization, crystal structure and supra­molecularity of ethyl (E)-2-cyano-3-(3-methyl­thio­phen-2-yl)acrylate and a new polymorph of ethyl (E)-2-cyano-3-(thio­phen-2-yl)acrylate

The synthesis, characterization and crystal structure of the title compounds are reported and the crystal supra­molecularity is discussed.

Abstract

The synthesis, crystal structure and structural motif of two thio­phene-based cyano­acrylate derivatives, namely, ethyl (E)-2-cyano-3-(3-methyl­thio­phen-2-yl)acrylate (1), C₁₁H₁₁NO₂S, and ethyl (E)-2-cyano-3-(thio­phen-2-yl)acrylate (2), C₁₀H₉NO₂S, are reported. Derivative 1 crystallized with two independent molecules in the asymmetric unit, and derivative 2 represents a new monoclinic (C2/m) polymorph. The mol­ecular conformations of 1 and the two polymorphs of 2 are very similar, as all non-H atoms are planar except for the methyl of the ethyl groups. The inter­molecular inter­actions and crystal packing of 1 and 2 are described and compared with that of the reported monoclinic (C2/m) polymorph of derivative 2 [Castro Agudelo et al. (2017 ▸). Acta Cryst. E73, 1287–1289].

Chemical context  

Cyano­acrylate derivatives are of industrial inter­est being subunits used to build many adhesives and polymeric materials (Faggi et al., 2019 ▸). They are also considered important inter­mediate precursors for the synthesis of different heterocyclic derivatives, see for example Qian et al. (2018 ▸), and as nitrile-activated species in bioreduction reactions (Brenna et al., 2013 ▸, 2015 ▸; Kong et al., 2016 ▸) among others. In addition, they show important practical properties, such as in organic dye-sensitized solar cells (DSSCs) (He et al., 2017 ▸; Zhou et al., 2015 ▸). Within these voltaic cells, cyano­acrylic acid is one of the most commonly employed acceptors. Thio­phene and its deriv­atives, known to exhibit high charge mobility, serve as π-bridges (donor-π–acceptor structure) to provide conjugation and enhance light absorbance (Liu et al., 2012 ▸).

An understanding of the structure of thio­phene-based acrylate subunits is necessary to benefit from their properties in photovoltaic cells. In a continuation of our work on the X-ray structural characterization of thio­phene-containing derivatives (Ibrahim et al., 2019 ▸; Al-Refai et al., 2014 ▸, 2016 ▸), we report here the synthesis, characterization and crystal structures of two thio­phene-based acrylate derivatives, namely, ethyl (E)-2-cyano-3-(3-methyl­thio­phen-2-yl)acrylate (1) and ethyl (E)-2-cyano-3-(3-methyl­thio­phen-2-yl)acrylate (2). Derivative 2 is a polymorph of a reported structure (Castro Agudelo et al., 2017 ▸), but with no disorder of the eth­oxy group. The crystal supra­molecularity of both com­pounds is also discussed.

Structural commentary  

The mol­ecular structures of the title compounds are depicted in Fig. 1 ▸. The asymmetric unit contains two independent mol­ecules, A and B, in 1 and one mol­ecule in 2. In these mol­ecules, the bond distances and angles fall within similar ranges to those reported for similar compounds (Castro Agudelo et al., 2017 ▸; Xu et al., 2016 ▸). In both compounds, all non-hydrogen atoms, except for the methyl groups, lie nearly in the same planes. The differences in torsion angles [C1—C2—C3—C4 = −177.78 (14) and C1—O2—C12—C13 = 83.60 (15)° (mol­ecule A), C14—C15—C16—C17 = 179.71 (15)° and C14—O15—C26—C27 = −88.66 (2)° (mol­ecule B) in 1 and C1—C2—C3—C4 = −178.77 (11) and C1—O2—C11—C12 = −83.41 (13)° in 2] indicate an out-of-plane deviation of the methyl group. The planarity of the mol­ecules allows intra­molecular hydrogen bonds to occur [C3—H3⋯O1 (mol­ecule A) and C16—H16⋯O14 (mol­ecule B) in 1; C3—H3⋯O1 in 2] (Fig. 1 ▸ and Tables 1 ▸ and 2 ▸), forming an S(6) ring motif with the carbonyl O and cyano N atoms consequently exhibiting an anti-configuration to each other. The conformation of the ethene bond is always E [C2=C3 = 1.363 (2) Å (mol­ecule A) and C15=C16 = 1.3625 (19) (mol­ecule B) in 1; C2=C3 = 1.3592 (18) Å in 2].

Figure 1.

Mol­ecular structures of compounds (a) 1 and (b) 2 with the atom-labelling scheme (displacement ellipsoids at 50% probability level). Intra­molecular C—H⋯O inter­actions are presented as red–white multi-band cylinders.

Table 1. Hydrogen-bond geometry (Å, °) for 1 .

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯O1	0.95	2.43	2.8136 (19)	104
C16—H16⋯O14	0.95	2.38	2.7829 (19)	105
C19—H19⋯O1i	0.95	2.34	3.2708 (19)	165
C22—H22A⋯O15ii	0.98	2.59	3.292 (2)	128

Symmetry codes: (i) ; (ii) .

Table 2. Hydrogen-bond geometry (Å, °) for 2 .

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯O1	0.964 (19)	2.444 (19)	2.7998 (18)	101.5 (14)
C3—H3⋯O1i	0.964 (19)	2.45 (2)	3.3436 (18)	153.4 (15)
C6—H6⋯N10ii	0.99 (2)	2.49 (2)	3.465 (2)	169.1 (18)
C8—H8⋯O1i	0.94 (2)	2.50 (2)	3.3047 (19)	143.6 (17)

Symmetry codes: (i) ; (ii) .

Derivative 2 is a polymorph of ethyl (E)-2-cyano-3-(­thio­phen-2-yl)acrylate (CSD refcode GEHYEA; Castro Agudelo et al., 2017 ▸). It shows a similar structure to 1, which has an extra methyl substituent on the thio­phene ring. In compound 1 and the two polymorphs of 2, all thio­phene-based cyano­acrylate non-H atoms, except for the ethyl group, lie in the same plane. It is also noteworthy that in the polymorph, the ethyl fragment occurs in more than one conformation, thus resulting in disorder, which is absent in 1 and 2.

Supra­molecular features  

In the crystal of 1, the A and B mol­ecules each form layers parallel to the ac plane, Fig. 2 ▸ a. The layers built up from chains of B mol­ecules are connected via C—H⋯O hydrogen bonds along the a axis. These chains are further connected through C—H⋯O inter­actions with stacks of mol­ecules A along the c axis. In the b-axis direction, inter­layered inter­actions through van der Waals forces and/or weak dipolar inter­actions generate a three-dimensional network. In the crystal of 2, inversion dimers are assembled along the c axis through C—H⋯O inter­actions, Fig. 2 ▸ b. Adjacent dimers (along the c axis) are further connected through C—H⋯N inter­actions, leading to infinite chains propagating along the c-axis direction. The resulting chains interact via van der Waals forces to form sheets parallel to the ac plane (Fig. 2 ▸ b). The sheets are connected through van der Waals forces and/or weak dipolar inter­actions, thus consolidating the three-dimensional framework structure. Compounds 1, 2 and the polymorph of 2 (Castro Agudelo et al., 2017 ▸) show no apparent degree of π–π stacking.

Figure 2.

(a) Partial packing diagram for 1 showing layers of A and B mol­ecules parallel to the ac plane, and connected via C—H⋯O inter­molecular inter­actions (shown as multi-band cylinders). (b) The intra­molecular (black and white) and inter­molecular (red and white) inter­actions in 2 forming chains of dimeric species connected via C—H⋯O and C—H⋯N inter­actions. In both figures, hydrogen atoms not involved in inter­actions are omitted for clarity.

The polymorph of 2 shows a similar crystal packing arrangement, the mol­ecules being connected via C—H⋯O/N inter­actions, generating centrosymmetric dimers. Chains of mol­ecules are further connected by van der Waals forces into sheets.

Database survey  

Castro Agudelo et al. (2017 ▸) reported a recent survey on the Cambridge Structural Database [CSD Version 5.37 with two updates; Groom et al., 2016 ▸] for hits containing the complete thio­phene-based cyano­acrylate fragment, together with the possibility of other five-membered rings and/or the presence of a saturated chain longer than the ethyl fragment. They found three hits containing the main part of the title compounds, the thio­phene-cyano­acrylate, with additional and/or longer substituents, namely ethyl-3-(3-chloro-4-cyano-5-{[4-(di­methyl­amino)­phen­yl]diazen­yl}-2-thien­yl)-2-cyano­acrylate (UMUYAE; Xu et al., 2016 ▸), octyl-2-cyano-3-(4,6-di­bromo-7,7-dimethyl-7H-thieno[3′,4′:4,5]silolo[2,3-b]thio­phen-2-yl)acrylate (QUSKAS; Liu et al., 2016 ▸) and ethyl-2-cyano-3-(3,3′′′-dihexyl-2,2′:5′,2′′:5′′,2′′′-quaterthio­phen-5-yl)acrylate (AVUFON; Miyazaki et al., 2011 ▸). In all derivatives AVUFON, UMUYAE and QUSKAS, the non-H thio­phene-based acrylate fragment is almost planar except for the methyl group (or the longer alkyl chain in QUSKAS) being slightly out of the plane. The crystal lattices of AVUFON, UMUYAE and QUSKAS are stabilized by C—H⋯O/S, C—H⋯O/N and C—H⋯N/S inter­molecular inter­actions, respectively.

A further search of the CSD for other five-membered rings instead of thio­phene provided six hits. Of them, the following three are very similar to the title compounds: ethyl-(2E)-2-cyano-3-(1-methyl-1H-pyrrol-2-yl)prop-2-enoate (AYUGEH; Asiri et al., 2011 ▸), (E)-ethyl-2-cyano-3-(1H-pyrrol-2-yl)acrylate (EVIZEP; Yuvaraj et al., 2011 ▸) and (E)-ethyl-2-cyano-3-(furan-2-yl)acrylate (ZAQKIN; Kalkhambkar et al., 2012 ▸). In both AYUGEH and EVIZEP, all the non-H atoms are nearly in the same plane, while in ZAQKIN the furan-based cyano­acrylate moiety lies in the same plane except for the methyl groups, which are slightly out of plane. As far as crystal packing is concerned, the mol­ecules in EVIZEP and ZAQKIN are linked into dimers via N—H⋯O and C—H⋯O hydrogen bonds, respectively, while in AYUGEH the mol­ecules are linked into tapes via both C—H⋯O and C—H⋯N inter­actions. The tapes are further inter­connected by C—H⋯π inter­actions into a three-dimensional structure.

Synthesis and crystallization  

All reagents and solvent were purchased from Aldrich and used without further purifications. The title compounds were synthesized as outlined in Fig. 3 ▸.

Figure 3.

Syntheis of the title compounds.

In a 250 ml round-bottom flask connected with a condenser, a mixture of the corresponding thio­phene-2-carboxaldehyde (1 mmol), ethyl­cyano­acetate (1.1 mmol) and ammonium acetate (8 mmol) in absolute ethanol was refluxed for 6 h. The reaction was monitored using thin layer chromatography (TLC plates coated with silica gel). After completion, the reaction mixture was cooled to room temperature, and the obtained yellowish-brown precipitate was filtered off, washed with cooled water, dried and recrystallized from ethanol solution to give the final products as pale-yellow crystals (90% yield for both 1 and 2).

Ethyl (E)-2-cyano-3-(3-methyl­thio­phen-2-yl)acrylate (1): m.p. 381–382 K, ¹H NMR (CD₂Cl₂, 300 MHz): δ (ppm) = 1.39 (t, J = 7.12, 3H, CH₂CH₃), 2.48 (s, 3H, CH₃-3′), 4.36 (q, J = 7.12, 2H, CH₂CH₃), 7.07 (d, J = 5.01,1H, H-4′), 7.74 (d, J = 5.01, 1H, H-5′), 8.46 (s, 1H, H-3). ¹³C NMR (CD₂Cl₂, 75 MHz) δ (ppm) = 14.4 (CH₂CH₃), 14.9 (CH₃-3′), 62.7 (CH₂CH₃), 98.0 (C-2), 116.4 (CN), 131.2 (C-2′), 131.4 (C-4′), 134.3 (C-5′), 145.0 (C-3), 149.9 (C-3′), 163.4 (C-1). (+)-ESIMS m/z = 244 ([M + Na]⁺, 100%), 465 ([2M + Na]⁺, 16%).

Ethyl (E)-2-cyano-3-(thio­phen-2-yl)acrylate (2): mp. 371–372 K, ¹H NMR (CD₂Cl₂, 300 MHz): δ (ppm) = 1.39 (t, J = 7.12, 3H, CH₂CH₃), 4.37 (q, J = 7.12, 2H, CH₂CH₃), 7.27 (t, J = 4.44,1H, H-4′), 7.85 (d, J = 4.36, 2H, H-3′,5′), 8.38 (s, 1H, H-3). ¹³C NMR (CD₂Cl₂, 75 MHz) δ (ppm) = 14.4 (CH₂CH₃), 62.9 (CH₂CH₃), 99.8 (C-2), 116.1 (CN), 129.0 (C-4′), 135.5 (C-5′), 136.5 (C-2′), 137.8 (C-3′), 146.9 (C-3), 162.9 (C-1). (+)-ESIMS m/z = 230 ([M + Na]⁺, 100%), 237 ([2M + Na]⁺, 11%).

Refinement  

Detailed crystal data and structure refinement for the title compounds are listed in Table 3 ▸. In 1, C-bound hydrogen atoms were included in calculated positions (0.95–0.99 Å) and refined using a riding model with U _iso(H) = 1.2U _eq(C) or 1.5U _eq(C-meth­yl). Methyl groups were allowed to rotate to fit best the electron density. All hydrogen atoms in 2 were located in difference-Fourier maps and refined isotropically.

Table 3. Experimental details.

	1	2
Crystal data
Chemical formula	C11H11NO2S	C10H9NO2S
M r	221.27	207.24
Crystal system, space group	Triclinic, P	Monoclinic, P21/c
Temperature (K)	100	100
a, b, c (Å)	9.2784 (2), 10.7925 (3), 11.6696 (2)	11.5907 (3), 6.6883 (2), 13.4837 (3)
α, β, γ (°)	74.464 (2), 74.179 (2), 85.073 (2)	90, 107.859 (2), 90
V (Å3)	1083.11 (4)	994.92 (5)
Z	4	4
Radiation type	Cu Kα	Cu Kα
μ (mm−1)	2.49	2.68
Crystal size (mm)	0.26 × 0.24 × 0.11	0.32 × 0.20 × 0.20
Data collection
Diffractometer	Stoe STADIVARI	Stoe STADIVARI
Absorption correction	Multi-scan (LANA; Stoe & Cie, 2016 ▸)	Multi-scan (LANA; Stoe & Cie, 2016 ▸)
T min, T max	0.074, 0.546	0.051, 0.168
No. of measured, independent and observed [I > 2σ(I)] reflections	21624, 4399, 3911	10400, 2048, 1974
R int	0.032	0.026
(sin θ/λ)max (Å−1)	0.630	0.630
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.041, 0.122, 1.10	0.033, 0.100, 1.09
No. of reflections	4399	2048
No. of parameters	275	164
H-atom treatment	H-atom parameters constrained	All H-atom parameters refined
Δρmax, Δρmin (e Å−3)	0.37, −0.49	0.29, −0.28

Computer programs: X-AREA Pilatus, Recipe and Integrate (Stoe & Cie, 2016 ▸) SHELXT2014 (Sheldrick, 2015a ▸), SHELXL2018 (Sheldrick, 2015b ▸) and DIAMOND (Crystal Impact, 2014 ▸).

Supplementary Material

CCDC references: 1947083, 1947082

Additional supporting information: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Ethyl (E)-2-cyano-3-(3-methylthiophen-2-yl)acrylate (1) . Crystal data

C11H11NO2S	Z = 4
Mr = 221.27	F(000) = 464
Triclinic, P1	Dx = 1.357 Mg m−3
a = 9.2784 (2) Å	Cu Kα radiation, λ = 1.54186 Å
b = 10.7925 (3) Å	Cell parameters from 24144 reflections
c = 11.6696 (2) Å	θ = 4.3–76.6°
α = 74.464 (2)°	µ = 2.49 mm−1
β = 74.179 (2)°	T = 100 K
γ = 85.073 (2)°	Plate, colourless
V = 1083.11 (4) Å3	0.26 × 0.24 × 0.11 mm

Ethyl (E)-2-cyano-3-(3-methylthiophen-2-yl)acrylate (1) . Data collection

Stoe STADIVARI diffractometer	4399 independent reflections
Radiation source: GeniX 3D HF Cu	3911 reflections with I > 2σ(I)
Detector resolution: 5.81 pixels mm-1	Rint = 0.032
rotation method, ω scans	θmax = 76.1°, θmin = 4.3°
Absorption correction: multi-scan (LANA; Stoe & Cie, 2016)	h = −11→11
Tmin = 0.074, Tmax = 0.546	k = −9→13
21624 measured reflections	l = −14→14

Ethyl (E)-2-cyano-3-(3-methylthiophen-2-yl)acrylate (1) . Refinement

Refinement on F2	Primary atom site location: dual
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.122	H-atom parameters constrained
S = 1.10	w = 1/[σ2(Fo2) + (0.0848P)2 + 0.1177P] where P = (Fo2 + 2Fc2)/3
4399 reflections	(Δ/σ)max = 0.001
275 parameters	Δρmax = 0.37 e Å−3
0 restraints	Δρmin = −0.49 e Å−3

Ethyl (E)-2-cyano-3-(3-methylthiophen-2-yl)acrylate (1) . Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Ethyl (E)-2-cyano-3-(3-methylthiophen-2-yl)acrylate (1) . Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.50743 (12)	0.18612 (11)	−0.05309 (9)	0.0282 (2)
C1	0.41104 (16)	0.24976 (14)	−0.00171 (13)	0.0244 (3)
O2	0.26787 (11)	0.25753 (11)	−0.00683 (9)	0.0272 (2)
C2	0.43611 (16)	0.33079 (14)	0.07627 (13)	0.0241 (3)
C3	0.57815 (16)	0.33732 (14)	0.08609 (13)	0.0237 (3)
H3	0.651544	0.290986	0.038820	0.028*
C4	0.63437 (16)	0.40276 (14)	0.15613 (13)	0.0237 (3)
S5	0.52472 (4)	0.48985 (3)	0.25473 (3)	0.02482 (13)
C6	0.67767 (17)	0.52373 (15)	0.29500 (13)	0.0279 (3)
H6	0.673143	0.573149	0.352151	0.033*
C7	0.80743 (16)	0.47210 (15)	0.23616 (13)	0.0271 (3)
H7	0.902616	0.481512	0.248382	0.033*
C8	0.78481 (16)	0.40304 (14)	0.15496 (13)	0.0253 (3)
C9	0.90876 (16)	0.33949 (15)	0.07698 (14)	0.0288 (3)
H9A	1.002445	0.344255	0.098973	0.043*
H9B	0.920518	0.383536	−0.010108	0.043*
H9C	0.884318	0.249167	0.091128	0.043*
C10	0.30968 (16)	0.39583 (15)	0.13711 (13)	0.0260 (3)
N11	0.20792 (14)	0.44850 (13)	0.18585 (12)	0.0307 (3)
C12	0.22775 (17)	0.18030 (16)	−0.07799 (14)	0.0293 (3)
H12A	0.311397	0.179597	−0.151655	0.035*
H12B	0.138713	0.218888	−0.106211	0.035*
C13	0.19407 (17)	0.04420 (16)	−0.00130 (15)	0.0335 (3)
H13A	0.154960	−0.003295	−0.046871	0.050*
H13B	0.119282	0.045515	0.076064	0.050*
H13C	0.286108	0.002013	0.016692	0.050*
O14	0.39990 (12)	0.67602 (12)	0.40403 (10)	0.0326 (3)
C14	0.29946 (16)	0.72830 (15)	0.46523 (13)	0.0262 (3)
O15	0.15438 (11)	0.72446 (11)	0.46857 (10)	0.0285 (2)
C15	0.32273 (16)	0.80391 (14)	0.54804 (13)	0.0251 (3)
C16	0.46568 (16)	0.81134 (14)	0.55532 (12)	0.0246 (3)
H16	0.538142	0.766223	0.506059	0.029*
C17	0.52508 (16)	0.87543 (14)	0.62444 (13)	0.0245 (3)
S18	0.42127 (4)	0.96642 (3)	0.72124 (3)	0.02552 (13)
C19	0.57711 (17)	0.99953 (15)	0.75821 (13)	0.0282 (3)
H19	0.575810	1.050830	0.813150	0.034*
C20	0.70388 (17)	0.94398 (15)	0.69991 (13)	0.0279 (3)
H20	0.800387	0.952569	0.710077	0.033*
C22	0.79644 (17)	0.80089 (16)	0.54916 (14)	0.0306 (3)
H22A	0.894192	0.818438	0.558037	0.046*
H22B	0.796091	0.829397	0.462132	0.046*
H22C	0.777504	0.708354	0.579387	0.046*
C21	0.67641 (16)	0.87201 (15)	0.62249 (13)	0.0258 (3)
C23	0.19658 (16)	0.86371 (15)	0.61513 (13)	0.0271 (3)
N24	0.09612 (15)	0.91263 (14)	0.67014 (12)	0.0324 (3)
C26	0.11875 (17)	0.65600 (15)	0.38777 (14)	0.0300 (3)
H26A	0.017243	0.619428	0.424811	0.036*
H26B	0.191159	0.584110	0.378726	0.036*
C27	0.12498 (19)	0.74571 (17)	0.26288 (14)	0.0360 (4)
H27A	0.092643	0.700287	0.212052	0.054*
H27B	0.227878	0.775245	0.222919	0.054*
H27C	0.058482	0.819932	0.272496	0.054*

Ethyl (E)-2-cyano-3-(3-methylthiophen-2-yl)acrylate (1) . Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0258 (5)	0.0336 (6)	0.0305 (5)	0.0029 (4)	−0.0085 (4)	−0.0166 (4)
C1	0.0237 (7)	0.0275 (8)	0.0244 (6)	0.0005 (5)	−0.0079 (5)	−0.0096 (6)
O2	0.0232 (5)	0.0346 (6)	0.0320 (5)	0.0020 (4)	−0.0115 (4)	−0.0185 (4)
C2	0.0237 (7)	0.0268 (8)	0.0249 (6)	0.0014 (5)	−0.0086 (5)	−0.0101 (6)
C3	0.0238 (7)	0.0258 (7)	0.0237 (6)	0.0005 (5)	−0.0065 (5)	−0.0098 (5)
C4	0.0230 (7)	0.0265 (8)	0.0253 (6)	0.0019 (5)	−0.0076 (5)	−0.0121 (5)
S5	0.0228 (2)	0.0302 (2)	0.0267 (2)	0.00155 (14)	−0.00801 (14)	−0.01489 (15)
C6	0.0293 (7)	0.0315 (8)	0.0290 (7)	−0.0017 (6)	−0.0115 (6)	−0.0135 (6)
C7	0.0253 (7)	0.0313 (8)	0.0291 (7)	−0.0012 (6)	−0.0101 (6)	−0.0115 (6)
C8	0.0244 (7)	0.0282 (8)	0.0251 (6)	0.0002 (5)	−0.0071 (5)	−0.0095 (6)
C9	0.0226 (7)	0.0357 (9)	0.0311 (7)	0.0029 (6)	−0.0068 (6)	−0.0149 (6)
C10	0.0256 (7)	0.0302 (8)	0.0280 (6)	0.0005 (6)	−0.0117 (5)	−0.0126 (6)
N11	0.0263 (6)	0.0384 (8)	0.0342 (6)	0.0030 (5)	−0.0103 (5)	−0.0190 (6)
C12	0.0282 (7)	0.0361 (9)	0.0325 (7)	0.0023 (6)	−0.0134 (6)	−0.0188 (6)
C13	0.0303 (7)	0.0382 (9)	0.0393 (8)	−0.0019 (6)	−0.0111 (6)	−0.0194 (7)
O14	0.0289 (5)	0.0416 (7)	0.0359 (6)	0.0049 (5)	−0.0102 (4)	−0.0239 (5)
C14	0.0258 (7)	0.0296 (8)	0.0264 (7)	0.0007 (6)	−0.0088 (5)	−0.0105 (6)
O15	0.0249 (5)	0.0360 (6)	0.0312 (5)	−0.0003 (4)	−0.0092 (4)	−0.0175 (4)
C15	0.0252 (7)	0.0285 (8)	0.0248 (6)	0.0017 (5)	−0.0076 (5)	−0.0116 (5)
C16	0.0255 (7)	0.0277 (8)	0.0232 (6)	0.0005 (5)	−0.0068 (5)	−0.0106 (5)
C17	0.0247 (7)	0.0278 (8)	0.0242 (6)	0.0014 (5)	−0.0068 (5)	−0.0121 (5)
S18	0.0248 (2)	0.0310 (2)	0.0255 (2)	0.00185 (14)	−0.00731 (14)	−0.01494 (15)
C19	0.0319 (7)	0.0306 (8)	0.0273 (7)	−0.0015 (6)	−0.0111 (6)	−0.0124 (6)
C20	0.0281 (7)	0.0322 (8)	0.0283 (7)	−0.0023 (6)	−0.0108 (6)	−0.0119 (6)
C22	0.0261 (7)	0.0364 (9)	0.0325 (7)	0.0043 (6)	−0.0077 (6)	−0.0158 (6)
C21	0.0245 (7)	0.0294 (8)	0.0259 (7)	0.0005 (6)	−0.0073 (5)	−0.0105 (6)
C23	0.0268 (7)	0.0312 (8)	0.0278 (7)	0.0002 (6)	−0.0105 (6)	−0.0117 (6)
N24	0.0272 (6)	0.0403 (8)	0.0342 (7)	0.0025 (5)	−0.0078 (5)	−0.0178 (6)
C26	0.0300 (7)	0.0338 (9)	0.0337 (8)	−0.0012 (6)	−0.0112 (6)	−0.0179 (6)
C27	0.0377 (8)	0.0441 (10)	0.0341 (8)	−0.0029 (7)	−0.0139 (6)	−0.0179 (7)

Ethyl (E)-2-cyano-3-(3-methylthiophen-2-yl)acrylate (1) . Geometric parameters (Å, º)

O1—C1	1.2057 (17)	O14—C14	1.2081 (18)
C1—O2	1.3404 (17)	C14—O15	1.3399 (17)
C1—C2	1.4912 (19)	C14—C15	1.4876 (19)
O2—C12	1.4545 (16)	O15—C26	1.4593 (16)
C2—C3	1.363 (2)	C15—C16	1.3625 (19)
C2—C10	1.4298 (19)	C15—C23	1.428 (2)
C3—C4	1.4296 (19)	C16—C17	1.4282 (19)
C3—H3	0.9500	C16—H16	0.9500
C4—C8	1.3925 (19)	C17—C21	1.3955 (19)
C4—S5	1.7375 (14)	C17—S18	1.7339 (14)
S5—C6	1.7068 (14)	S18—C19	1.7076 (15)
C6—C7	1.368 (2)	C19—C20	1.366 (2)
C6—H6	0.9500	C19—H19	0.9500
C7—C8	1.4181 (19)	C20—C21	1.421 (2)
C7—H7	0.9500	C20—H20	0.9500
C8—C9	1.4997 (19)	C22—C21	1.499 (2)
C9—H9A	0.9800	C22—H22A	0.9800
C9—H9B	0.9800	C22—H22B	0.9800
C9—H9C	0.9800	C22—H22C	0.9800
C10—N11	1.1517 (19)	C23—N24	1.153 (2)
C12—C13	1.509 (2)	C26—C27	1.508 (2)
C12—H12A	0.9900	C26—H26A	0.9900
C12—H12B	0.9900	C26—H26B	0.9900
C13—H13A	0.9800	C27—H27A	0.9800
C13—H13B	0.9800	C27—H27B	0.9800
C13—H13C	0.9800	C27—H27C	0.9800
O1—C1—O2	124.91 (13)	O14—C14—O15	124.76 (13)
O1—C1—C2	124.13 (13)	O14—C14—C15	123.55 (13)
O2—C1—C2	110.96 (12)	O15—C14—C15	111.68 (12)
C1—O2—C12	116.44 (11)	C14—O15—C26	116.44 (11)
C3—C2—C10	123.99 (13)	C16—C15—C23	123.75 (13)
C3—C2—C1	117.90 (13)	C16—C15—C14	117.06 (13)
C10—C2—C1	118.10 (12)	C23—C15—C14	119.19 (12)
C2—C3—C4	130.33 (14)	C15—C16—C17	130.94 (14)
C2—C3—H3	114.8	C15—C16—H16	114.5
C4—C3—H3	114.8	C17—C16—H16	114.5
C8—C4—C3	123.93 (13)	C21—C17—C16	123.66 (14)
C8—C4—S5	111.36 (10)	C21—C17—S18	111.12 (11)
C3—C4—S5	124.71 (11)	C16—C17—S18	125.22 (11)
C6—S5—C4	91.34 (7)	C19—S18—C17	91.77 (7)
C7—C6—S5	112.77 (11)	C20—C19—S18	112.44 (11)
C7—C6—H6	123.6	C20—C19—H19	123.8
S5—C6—H6	123.6	S18—C19—H19	123.8
C6—C7—C8	112.84 (13)	C19—C20—C21	113.02 (13)
C6—C7—H7	123.6	C19—C20—H20	123.5
C8—C7—H7	123.6	C21—C20—H20	123.5
C4—C8—C7	111.68 (13)	C21—C22—H22A	109.5
C4—C8—C9	124.57 (13)	C21—C22—H22B	109.5
C7—C8—C9	123.75 (13)	H22A—C22—H22B	109.5
C8—C9—H9A	109.5	C21—C22—H22C	109.5
C8—C9—H9B	109.5	H22A—C22—H22C	109.5
H9A—C9—H9B	109.5	H22B—C22—H22C	109.5
C8—C9—H9C	109.5	C17—C21—C20	111.66 (13)
H9A—C9—H9C	109.5	C17—C21—C22	124.81 (13)
H9B—C9—H9C	109.5	C20—C21—C22	123.53 (13)
N11—C10—C2	179.8 (2)	N24—C23—C15	178.96 (15)
O2—C12—C13	110.63 (12)	O15—C26—C27	110.46 (12)
O2—C12—H12A	109.5	O15—C26—H26A	109.6
C13—C12—H12A	109.5	C27—C26—H26A	109.6
O2—C12—H12B	109.5	O15—C26—H26B	109.6
C13—C12—H12B	109.5	C27—C26—H26B	109.6
H12A—C12—H12B	108.1	H26A—C26—H26B	108.1
C12—C13—H13A	109.5	C26—C27—H27A	109.5
C12—C13—H13B	109.5	C26—C27—H27B	109.5
H13A—C13—H13B	109.5	H27A—C27—H27B	109.5
C12—C13—H13C	109.5	C26—C27—H27C	109.5
H13A—C13—H13C	109.5	H27A—C27—H27C	109.5
H13B—C13—H13C	109.5	H27B—C27—H27C	109.5
O1—C1—O2—C12	1.4 (2)	O14—C14—O15—C26	−2.6 (2)
C2—C1—O2—C12	−178.63 (12)	C15—C14—O15—C26	178.16 (12)
O1—C1—C2—C3	2.7 (2)	O14—C14—C15—C16	−1.2 (2)
O2—C1—C2—C3	−177.20 (13)	O15—C14—C15—C16	178.04 (13)
O1—C1—C2—C10	−176.67 (14)	O14—C14—C15—C23	179.03 (15)
O2—C1—C2—C10	3.39 (18)	O15—C14—C15—C23	−1.8 (2)
C10—C2—C3—C4	1.6 (3)	C23—C15—C16—C17	−0.5 (3)
C1—C2—C3—C4	−177.78 (14)	C14—C15—C16—C17	179.71 (15)
C2—C3—C4—C8	−178.52 (15)	C15—C16—C17—C21	179.19 (16)
C2—C3—C4—S5	2.4 (2)	C15—C16—C17—S18	−0.6 (2)
C8—C4—S5—C6	−0.81 (12)	C21—C17—S18—C19	0.10 (12)
C3—C4—S5—C6	178.37 (14)	C16—C17—S18—C19	179.92 (14)
C4—S5—C6—C7	0.29 (12)	C17—S18—C19—C20	−0.07 (13)
S5—C6—C7—C8	0.30 (17)	S18—C19—C20—C21	0.02 (18)
C3—C4—C8—C7	−178.06 (14)	C16—C17—C21—C20	−179.93 (14)
S5—C4—C8—C7	1.12 (16)	S18—C17—C21—C20	−0.11 (17)
C3—C4—C8—C9	2.5 (2)	C16—C17—C21—C22	−0.4 (2)
S5—C4—C8—C9	−178.36 (12)	S18—C17—C21—C22	179.43 (12)
C6—C7—C8—C4	−0.93 (19)	C19—C20—C21—C17	0.1 (2)
C6—C7—C8—C9	178.56 (14)	C19—C20—C21—C22	−179.49 (14)
C1—O2—C12—C13	83.60 (15)	C14—O15—C26—C27	−88.66 (16)

Ethyl (E)-2-cyano-3-(3-methylthiophen-2-yl)acrylate (1) . Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O1	0.95	2.43	2.8136 (19)	104
C16—H16···O14	0.95	2.38	2.7829 (19)	105
C19—H19···O1i	0.95	2.34	3.2708 (19)	165
C22—H22A···O15ii	0.98	2.59	3.292 (2)	128

Symmetry codes: (i) x, y+1, z+1; (ii) x+1, y, z.

Ethyl (E)-2-cyano-3-(thiophen-2-yl)acrylate (2) . Crystal data

C10H9NO2S	F(000) = 432
Mr = 207.24	Dx = 1.384 Mg m−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54186 Å
a = 11.5907 (3) Å	Cell parameters from 15380 reflections
b = 6.6883 (2) Å	θ = 3.5–76.4°
c = 13.4837 (3) Å	µ = 2.68 mm−1
β = 107.859 (2)°	T = 100 K
V = 994.92 (5) Å3	Block, colourless
Z = 4	0.32 × 0.20 × 0.20 mm

Ethyl (E)-2-cyano-3-(thiophen-2-yl)acrylate (2) . Data collection

Stoe STADIVARI diffractometer	2048 independent reflections
Radiation source: GeniX 3D HF Cu	1974 reflections with I > 2σ(I)
Detector resolution: 5.81 pixels mm-1	Rint = 0.026
rotation method, ω scans	θmax = 76.3°, θmin = 6.8°
Absorption correction: multi-scan (LANA; Stoe & Cie, 2016)	h = −14→14
Tmin = 0.051, Tmax = 0.168	k = −8→8
10400 measured reflections	l = −16→10

Ethyl (E)-2-cyano-3-(thiophen-2-yl)acrylate (2) . Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.033	All H-atom parameters refined
wR(F2) = 0.100	w = 1/[σ2(Fo2) + (0.0688P)2 + 0.2209P] where P = (Fo2 + 2Fc2)/3
S = 1.09	(Δ/σ)max < 0.001
2048 reflections	Δρmax = 0.29 e Å−3
164 parameters	Δρmin = −0.28 e Å−3
0 restraints	Extinction correction: SHELXL-2018/3 (Sheldrick 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: dual	Extinction coefficient: 0.0030 (6)

Ethyl (E)-2-cyano-3-(thiophen-2-yl)acrylate (2) . Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Ethyl (E)-2-cyano-3-(thiophen-2-yl)acrylate (2) . Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.67411 (9)	0.47068 (14)	0.54042 (8)	0.0266 (3)
C1	0.72087 (12)	0.46539 (17)	0.47233 (11)	0.0214 (3)
O2	0.84079 (8)	0.45263 (13)	0.48771 (8)	0.0238 (2)
C2	0.65241 (12)	0.46897 (17)	0.35943 (11)	0.0211 (3)
C3	0.52935 (12)	0.47114 (18)	0.33171 (11)	0.0215 (3)
H3	0.4938 (17)	0.475 (2)	0.3876 (14)	0.025 (4)*
C4	0.44161 (12)	0.47115 (17)	0.23001 (11)	0.0210 (3)
S5	0.47197 (3)	0.46815 (5)	0.11198 (2)	0.02218 (16)
C6	0.32131 (13)	0.47018 (18)	0.04368 (12)	0.0250 (3)
H6	0.301 (2)	0.470 (3)	−0.0329 (19)	0.044 (6)*
C7	0.24983 (13)	0.47201 (19)	0.10750 (12)	0.0256 (3)
H7	0.158 (2)	0.472 (3)	0.0817 (19)	0.053 (6)*
C8	0.31729 (13)	0.47269 (18)	0.21394 (12)	0.0229 (3)
H8	0.2819 (18)	0.476 (2)	0.2678 (16)	0.031 (5)*
C9	0.71814 (12)	0.46836 (18)	0.28517 (11)	0.0223 (3)
H9	0.8744 (14)	0.354 (3)	0.6320 (12)	0.026 (4)*
N10	0.76940 (11)	0.46866 (17)	0.22440 (10)	0.0272 (3)
H10	0.9901 (15)	0.379 (3)	0.5923 (13)	0.029 (4)*
C11	0.91574 (13)	0.4415 (2)	0.59654 (12)	0.0277 (3)
H11	0.8636 (16)	0.712 (3)	0.6428 (13)	0.039 (5)*
C12	0.94012 (13)	0.6466 (3)	0.64456 (12)	0.0355 (3)
H12	0.9946 (17)	0.630 (3)	0.7176 (16)	0.051 (5)*
H13	0.9802 (15)	0.731 (3)	0.6063 (14)	0.044 (5)*

Ethyl (E)-2-cyano-3-(thiophen-2-yl)acrylate (2) . Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0208 (5)	0.0392 (6)	0.0210 (5)	0.0009 (4)	0.0081 (4)	0.0005 (4)
C1	0.0179 (6)	0.0224 (6)	0.0235 (7)	−0.0005 (4)	0.0055 (5)	−0.0001 (4)
O2	0.0170 (5)	0.0334 (5)	0.0205 (5)	0.0013 (3)	0.0050 (4)	0.0002 (3)
C2	0.0196 (6)	0.0236 (6)	0.0203 (7)	0.0004 (4)	0.0062 (5)	0.0002 (4)
C3	0.0205 (7)	0.0220 (7)	0.0225 (7)	0.0002 (4)	0.0071 (5)	−0.0001 (4)
C4	0.0202 (7)	0.0236 (6)	0.0203 (7)	−0.0006 (4)	0.0077 (5)	−0.0004 (4)
S5	0.0193 (2)	0.0285 (2)	0.0190 (2)	−0.00064 (10)	0.00624 (14)	−0.00010 (10)
C6	0.0221 (6)	0.0269 (7)	0.0234 (7)	−0.0009 (5)	0.0033 (5)	0.0002 (5)
C7	0.0196 (6)	0.0290 (7)	0.0264 (8)	−0.0006 (5)	0.0046 (5)	0.0004 (5)
C8	0.0210 (7)	0.0240 (6)	0.0236 (7)	−0.0003 (4)	0.0068 (5)	−0.0001 (4)
C9	0.0178 (6)	0.0245 (7)	0.0231 (7)	0.0000 (4)	0.0040 (5)	0.0003 (4)
N10	0.0213 (6)	0.0371 (7)	0.0236 (6)	0.0006 (4)	0.0073 (5)	0.0007 (4)
C11	0.0195 (6)	0.0398 (7)	0.0212 (7)	0.0042 (5)	0.0024 (5)	0.0014 (5)
C12	0.0229 (6)	0.0484 (9)	0.0318 (8)	0.0018 (6)	0.0032 (5)	−0.0091 (7)

Ethyl (E)-2-cyano-3-(thiophen-2-yl)acrylate (2) . Geometric parameters (Å, º)

O1—C1	1.2012 (18)	C6—H6	0.99 (2)
C1—O2	1.3438 (15)	C7—C8	1.408 (2)
C1—C2	1.4855 (19)	C7—H7	1.01 (2)
O2—C11	1.4600 (16)	C8—H8	0.938 (19)
C2—C3	1.3592 (18)	C9—N10	1.1501 (19)
C2—C9	1.4322 (18)	C11—C12	1.506 (2)
C3—C4	1.4350 (19)	C11—H9	0.969 (16)
C3—H3	0.964 (18)	C11—H10	0.976 (16)
C4—C8	1.3899 (19)	C12—H11	0.982 (18)
C4—S5	1.7323 (14)	C12—H12	1.00 (2)
S5—C6	1.7062 (15)	C12—H13	0.974 (19)
C6—C7	1.365 (2)
O1—C1—O2	124.87 (13)	C6—C7—H7	124.0 (14)
O1—C1—C2	123.94 (12)	C8—C7—H7	123.2 (14)
O2—C1—C2	111.18 (11)	C4—C8—C7	112.58 (13)
C1—O2—C11	115.27 (10)	C4—C8—H8	123.9 (13)
C3—C2—C9	123.10 (13)	C7—C8—H8	123.5 (13)
C3—C2—C1	117.88 (12)	N10—C9—C2	178.99 (14)
C9—C2—C1	119.01 (11)	O2—C11—C12	111.16 (12)
C2—C3—C4	129.73 (13)	O2—C11—H9	107.1 (10)
C2—C3—H3	116.7 (11)	C12—C11—H9	113.1 (10)
C4—C3—H3	113.5 (11)	O2—C11—H10	103.1 (10)
C8—C4—C3	123.09 (13)	C12—C11—H10	111.3 (10)
C8—C4—S5	110.48 (11)	H9—C11—H10	110.5 (13)
C3—C4—S5	126.43 (10)	C11—C12—H11	110.2 (11)
C6—S5—C4	91.90 (7)	C11—C12—H12	107.6 (13)
C7—C6—S5	112.23 (11)	H11—C12—H12	111.4 (15)
C7—C6—H6	131.8 (13)	C11—C12—H13	111.0 (11)
S5—C6—H6	116.0 (13)	H11—C12—H13	107.7 (15)
C6—C7—C8	112.81 (12)	H12—C12—H13	109.0 (15)
O1—C1—O2—C11	1.03 (17)	C2—C3—C4—S5	0.03 (19)
C2—C1—O2—C11	−178.07 (10)	C8—C4—S5—C6	0.27 (9)
O1—C1—C2—C3	−2.45 (17)	C3—C4—S5—C6	179.99 (11)
O2—C1—C2—C3	176.65 (10)	C4—S5—C6—C7	−0.31 (10)
O1—C1—C2—C9	178.04 (11)	S5—C6—C7—C8	0.27 (14)
O2—C1—C2—C9	−2.85 (15)	C3—C4—C8—C7	−179.90 (11)
C9—C2—C3—C4	0.7 (2)	S5—C4—C8—C7	−0.17 (13)
C1—C2—C3—C4	−178.77 (11)	C6—C7—C8—C4	−0.06 (16)
C2—C3—C4—C8	179.71 (12)	C1—O2—C11—C12	−83.41 (13)

Ethyl (E)-2-cyano-3-(thiophen-2-yl)acrylate (2) . Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O1	0.964 (19)	2.444 (19)	2.7998 (18)	101.5 (14)
C3—H3···O1i	0.964 (19)	2.45 (2)	3.3436 (18)	153.4 (15)
C6—H6···N10ii	0.99 (2)	2.49 (2)	3.465 (2)	169.1 (18)
C8—H8···O1i	0.94 (2)	2.50 (2)	3.3047 (19)	143.6 (17)

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

Funding Statement

This work was funded by Al al-Bayt University grant . Deutsche Forschungsgemeinschaft grant .