(E)-Ethyl 2-cyano-3-(1H-pyrrol-2-yl)acrylate

Abstract

All the non-H atoms of the title compound, C₁₀H₁₀N₂O₂, are nearly in the same plane with a maximum deviation of 0.093 (1) Å. In the crystal, adjacent mol­ecules are linked by pairs of inter­molecular N—H⋯O hydrogen bonds, generating inversion dimers with R ₂ ²(14) ring motifs.

Related literature

For background to and applications of pyrrole derivatives, see: Fischer & Orth (1934 ▶). For the Knoevenagel condensation reaction and its applications, see: Knoevenagel (1898 ▶); Bigi et al. (1999 ▶). For the synthesis of related compounds, see: Knizhnikov et al. (2007 ▶); Sarda et al. (2009 ▶). For related structures, see: Ye et al. (2009 ▶); Wang & Jian (2008 ▶); Zhang et al. (2009 ▶).

Experimental

Crystal data

• C₁₀H₁₀N₂O₂

• M _r = 190.20

• Monoclinic,

• a = 6.2811 (2) Å

• b = 9.4698 (3) Å

• c = 16.3936 (5) Å

• β = 92.645 (3)°

• V = 974.06 (5) ų

• Z = 4

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 293 K

• 0.30 × 0.20 × 0.15 mm

Data collection

• Oxford Diffraction Xcalibur Sapphire3 diffractometer

• Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010 ▶) T _min = 0.971, T _max = 0.986

• 18157 measured reflections

• 1908 independent reflections

• 1574 reflections with I > 2σ(I)

• R _int = 0.032

Refinement

• R[F ² > 2σ(F ²)] = 0.039

• wR(F ²) = 0.113

• S = 1.06

• 1908 reflections

• 128 parameters

• H-atom parameters constrained

• Δρ_max = 0.12 e Å⁻³

• Δρ_min = −0.19 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536811028790/is2752Isup3.cml

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O1i	0.86	2.09	2.874 (2)	151

Symmetry code: (i) .

supplementary crystallographic information

Comment

The chemistry of pyrrole compounds and biological activities of the related compounds has been extensively studied (Fischer & Orth, 1934). The Knoevenagel condensation is an important carbon–carbon bond forming reaction in organic synthesis (Knoevenagel, 1898). Ever since its discovery, the Knoevenagel reaction has been widely used in organic synthesis to prepare coumarins and their derivatives, which are important intermediates in the synthesis of cosmetics, perfumes and pharmaceuticals (Bigi et al., 1999). With the view of biological importance the title compound was synthesized and reported here its crystal structure.

Bond lengths and bond angles are comparable with the similar crystal structures solved earlier (Ye et al., 2009; Wang & Jian, 2008; Zhang et al., 2009). All the non-hydrogen atoms in the molecule are nearly in the same plane with the maximum out-of-plane deviation of 0.093 (1) Å (r.m.s. deviation = 0.04 Å). The crystal packing is stabilized by N—H···O intermolecular interactions, generating a centrosymmetric dimer of R₂²(14) ring.

Experimental

A solution of pyrrole-2-aldehyde (1 mol), ethyl cyanoacetate (1.2 mol) and piperidine (0.1 ml) in ethanol (20 ml) was stirred at room temperature for 8 h. After removal of the volatiles in vacuo, orange solid was obtained in quantitative yield. A sample for analysis was obtained by recrystallization from EtOAc as pale yellow needles: ¹H NMR (300 MHz, CDCl₃) δ p.p.m.: 1.38 t (3H, CH₃), 4.35 q (2H, CH₂), 6.41 m (1H, CH), 6.92 m (1H, CH), 7.22 m (1H, CH), 7.98 s (1H, HC=C), 9.92 s (1H, NH).

Refinement

All H atoms were refined using a riding model, with d(C—H) = 0.93 Å for aromatic, 0.97 Å for CH₂ and 0.96 Å for CH₃, and d(N—H) = 0.86 Å, and with U_iso(H) = 1.2U_eq(C, N) or 1.5U_eq(methylC)

Figures

Fig. 1.

The molecular structure of the title compound, showing 30% probability displacement ellipsoids.

Fig. 2.

A molecular packing view of the title compound, showing intermolecular interactions. For clarity, hydrogen atoms which are not involved in hydrogen bonding have been omitted.

Crystal data

C10H10N2O2	F(000) = 400
Mr = 190.20	Dx = 1.297 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 7544 reflections
a = 6.2811 (2) Å	θ = 3.5–29.0°
b = 9.4698 (3) Å	µ = 0.09 mm−1
c = 16.3936 (5) Å	T = 293 K
β = 92.645 (3)°	Rectangular, light yellow
V = 974.06 (5) Å3	0.30 × 0.20 × 0.15 mm
Z = 4

Data collection

Oxford Diffraction Xcalibur Sapphire3 diffractometer	1908 independent reflections
Radiation source: fine-focus sealed tube	1574 reflections with I > 2σ(I)
graphite	Rint = 0.032
Detector resolution: 16.1049 pixels mm-1	θmax = 26.0°, θmin = 3.5°
ω scans	h = −7→7
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010)	k = −11→11
Tmin = 0.971, Tmax = 0.986	l = −20→20
18157 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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.113	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0623P)2 + 0.1138P] where P = (Fo2 + 2Fc2)/3
1908 reflections	(Δ/σ)max < 0.001
128 parameters	Δρmax = 0.12 e Å−3
0 restraints	Δρmin = −0.19 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 (Ų)

	x	y	z	Uiso*/Ueq
C1	−0.1517 (2)	0.73171 (17)	0.56284 (9)	0.0557 (4)
H1	−0.2260	0.7170	0.6099	0.067*
C2	−0.2045 (3)	0.82705 (18)	0.50230 (9)	0.0596 (4)
H2	−0.3208	0.8879	0.5007	0.072*
C3	−0.0526 (2)	0.81600 (16)	0.44393 (9)	0.0522 (4)
H3	−0.0488	0.8687	0.3962	0.063*
C4	0.0926 (2)	0.71274 (13)	0.46903 (7)	0.0403 (3)
C5	0.2764 (2)	0.65298 (13)	0.43588 (8)	0.0403 (3)
H5	0.3441	0.5838	0.4679	0.048*
C6	0.36856 (19)	0.68137 (13)	0.36460 (7)	0.0390 (3)
C7	0.2877 (2)	0.78645 (15)	0.30869 (8)	0.0433 (3)
C8	0.5592 (2)	0.60070 (14)	0.34340 (7)	0.0400 (3)
C9	0.8147 (2)	0.56123 (16)	0.24473 (8)	0.0502 (4)
H9A	0.7809	0.4614	0.2415	0.060*
H9B	0.9363	0.5737	0.2827	0.060*
C10	0.8645 (3)	0.61655 (18)	0.16209 (9)	0.0593 (4)
H10A	0.7448	0.6008	0.1247	0.089*
H10B	0.9870	0.5683	0.1429	0.089*
H10C	0.8937	0.7159	0.1657	0.089*
N1	0.02503 (19)	0.66332 (12)	0.54287 (7)	0.0472 (3)
H1A	0.0873	0.5982	0.5717	0.057*
N2	0.2208 (2)	0.87126 (15)	0.26485 (8)	0.0631 (4)
O1	0.63859 (15)	0.50906 (11)	0.38609 (6)	0.0539 (3)
O2	0.63298 (14)	0.64028 (10)	0.27206 (5)	0.0454 (3)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.0510 (8)	0.0684 (10)	0.0490 (8)	0.0055 (7)	0.0159 (6)	−0.0045 (7)
C2	0.0537 (9)	0.0672 (10)	0.0587 (9)	0.0183 (7)	0.0105 (7)	0.0000 (8)
C3	0.0544 (8)	0.0562 (9)	0.0464 (8)	0.0119 (7)	0.0072 (6)	0.0048 (6)
C4	0.0420 (7)	0.0431 (7)	0.0359 (6)	−0.0008 (6)	0.0034 (5)	−0.0025 (5)
C5	0.0402 (7)	0.0420 (7)	0.0386 (7)	0.0013 (5)	0.0018 (5)	−0.0001 (5)
C6	0.0375 (7)	0.0422 (7)	0.0375 (6)	−0.0014 (5)	0.0024 (5)	0.0005 (5)
C7	0.0414 (7)	0.0477 (8)	0.0412 (7)	0.0014 (6)	0.0068 (5)	0.0012 (6)
C8	0.0388 (7)	0.0434 (7)	0.0380 (7)	−0.0012 (5)	0.0032 (5)	0.0002 (5)
C9	0.0450 (7)	0.0541 (8)	0.0526 (8)	0.0072 (6)	0.0133 (6)	0.0026 (7)
C10	0.0608 (9)	0.0625 (10)	0.0565 (9)	0.0038 (7)	0.0227 (7)	0.0043 (7)
N1	0.0487 (7)	0.0524 (7)	0.0412 (6)	0.0062 (5)	0.0091 (5)	0.0043 (5)
N2	0.0660 (9)	0.0669 (8)	0.0570 (8)	0.0129 (7)	0.0092 (6)	0.0184 (7)
O1	0.0540 (6)	0.0611 (6)	0.0474 (6)	0.0163 (5)	0.0092 (4)	0.0123 (5)
O2	0.0425 (5)	0.0507 (6)	0.0437 (5)	0.0047 (4)	0.0120 (4)	0.0066 (4)

Geometric parameters (Å, °)

C1—N1	1.3386 (18)	C6—C8	1.4753 (18)
C1—C2	1.371 (2)	C7—N2	1.1447 (17)
C1—H1	0.9300	C8—O1	1.2080 (15)
C2—C3	1.386 (2)	C8—O2	1.3316 (15)
C2—H2	0.9300	C9—O2	1.4528 (16)
C3—C4	1.3869 (19)	C9—C10	1.4991 (19)
C3—H3	0.9300	C9—H9A	0.9700
C4—N1	1.3827 (16)	C9—H9B	0.9700
C4—C5	1.4165 (18)	C10—H10A	0.9600
C5—C6	1.3546 (18)	C10—H10B	0.9600
C5—H5	0.9300	C10—H10C	0.9600
C6—C7	1.4301 (18)	N1—H1A	0.8600
N1—C1—C2	108.49 (12)	O1—C8—O2	124.05 (12)
N1—C1—H1	125.8	O1—C8—C6	123.60 (11)
C2—C1—H1	125.8	O2—C8—C6	112.35 (11)
C1—C2—C3	107.40 (13)	O2—C9—C10	107.37 (12)
C1—C2—H2	126.3	O2—C9—H9A	110.2
C3—C2—H2	126.3	C10—C9—H9A	110.2
C2—C3—C4	108.22 (13)	O2—C9—H9B	110.2
C2—C3—H3	125.9	C10—C9—H9B	110.2
C4—C3—H3	125.9	H9A—C9—H9B	108.5
N1—C4—C3	105.90 (12)	C9—C10—H10A	109.5
N1—C4—C5	119.30 (12)	C9—C10—H10B	109.5
C3—C4—C5	134.80 (12)	H10A—C10—H10B	109.5
C6—C5—C4	129.78 (12)	C9—C10—H10C	109.5
C6—C5—H5	115.1	H10A—C10—H10C	109.5
C4—C5—H5	115.1	H10B—C10—H10C	109.5
C5—C6—C7	122.53 (12)	C1—N1—C4	110.00 (12)
C5—C6—C8	118.95 (11)	C1—N1—H1A	125.0
C7—C6—C8	118.53 (11)	C4—N1—H1A	125.0
N2—C7—C6	178.93 (14)	C8—O2—C9	115.85 (10)
N1—C1—C2—C3	−0.38 (18)	C7—C6—C8—O1	−179.34 (12)
C1—C2—C3—C4	0.31 (18)	C5—C6—C8—O2	−179.66 (11)
C2—C3—C4—N1	−0.12 (16)	C7—C6—C8—O2	0.57 (17)
C2—C3—C4—C5	178.72 (15)	C2—C1—N1—C4	0.31 (18)
N1—C4—C5—C6	178.23 (12)	C3—C4—N1—C1	−0.11 (16)
C3—C4—C5—C6	−0.5 (3)	C5—C4—N1—C1	−179.17 (12)
C4—C5—C6—C7	1.1 (2)	O1—C8—O2—C9	2.78 (19)
C4—C5—C6—C8	−178.64 (12)	C6—C8—O2—C9	−177.13 (10)
C5—C6—C8—O1	0.4 (2)	C10—C9—O2—C8	176.96 (11)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1i	0.86	2.09	2.874 (2)	151

Symmetry codes: (i) −x+1, −y+1, −z+1.