(E)-2-(2-Nitro­ethen­yl)furan

Abstract

The title compound, C₆H₅NO₃, was synthesized via condensation of furfural with nitro­methane in the presence of isobutyl­amine. The compound crystallizes exclusively as the E isomer. The angle between the mean planes of the furan ring and the nitro­alkenyl group is 1.3 (2)°.

Related literature

For general background, see: Wang et al. (2009 ▶); An et al. (2007 ▶); Rastogi et al. (2006 ▶); Rao et al. (2005 ▶); Negrín et al. (2002 ▶, 2003 ▶); Vallejosa et al. (2005 ▶). For related structures, see: Martínez-Bescos et al. (2008 ▶); Novoa-de-Armas et al. (1997 ▶); Pomes et al. (1995 ▶).

Experimental

Crystal data

• C₆H₅NO₃

• M _r = 139.11

• Monoclinic,

• a = 9.0374 (18) Å

• b = 5.2012 (10) Å

• c = 13.027 (3) Å

• β = 97.58 (3)°

• V = 607.0 (2) ų

• Z = 4

• Mo Kα radiation

• μ = 0.13 mm⁻¹

• T = 100 K

• 0.47 × 0.17 × 0.14 mm

Data collection

• Bruker SMART APEX diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.916, T _max = 0.980

• 4852 measured reflections

• 1387 independent reflections

• 1317 reflections with I > 2σ(I)

• R _int = 0.023

Refinement

• R[F ² > 2σ(F ²)] = 0.041

• wR(F ²) = 0.107

• S = 1.06

• 1387 reflections

• 91 parameters

• H-atom parameters constrained

• Δρ_max = 0.25 e Å⁻³

• Δρ_min = −0.28 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

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

supplementary crystallographic information

Comment

Among the biological properties of (nitro-alkenyl)-furan compounds our interest is focused in their antibacterial and antifungal activities. In spite of the importance of the structure to explain physical and chemical properties, there are not reports on the structures of the more simple compounds in this family. We start with this study a series of structural reports about them. The structure of title compound, showing trans or E configuration, is shown in Fig. 1. Ring aromaticity is extended to the alkenyl group being C1—C5 bond length, 1.430 (2), significatively shorter than a single C—C bond. Alkenyl sp² carbons mantain coplanarity with furan ring as shown by an angle of 1.3 (2)° between ring plane and C5—C6—N1 plane. Crystal packing does not show hydrogen bonds nor N···π intermolecular interactions (Fig. 2).

Experimental

2-(2-Nitro-ethenyl)-furan, also called G-0, was obtained by a variation of Knoevenagel's method: condensation of an aldehyde with substances containing an active α-hydrogen in the presence of a base (ammonia or amines) as catalyst. The Centro de Bioactivos Químicos (Cuba) has already patented this modified method using furfural, an aromatic compound from acid hydrolisis of sugar cane residuals (straw, sawdust, etc.) and nitromethane in the presence of isobutylamine. A yellow crystalline solid was obtained with purity higher than 98%, melting point 74.5°, scarcely soluble in water and very soluble in nitromethane, carbon tetrachloride, petroleum ether and ethanol.

Refinement

All H atoms were positioned geometrically and treated as riding (C—H = 0.99Å for methylene and C—H = 0.93Å otherwise). U_iso(H) = 1.2 U_eq(C) of the carrier atom.

Figures

Fig. 1.

ORTEP representation of the molecular structure of the title compound showing the atom labelling scheme (thermal ellipsoid probability 50%).

Fig. 2.

Packing diagram of the title compound.

Crystal data

C6H5NO3	F(000) = 288
Mr = 139.11	Dx = 1.522 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2396 reflections
a = 9.0374 (18) Å	θ = 2.6–27.5°
b = 5.2012 (10) Å	µ = 0.13 mm−1
c = 13.027 (3) Å	T = 100 K
β = 97.58 (3)°	Prism, yellow
V = 607.0 (2) Å3	0.47 × 0.17 × 0.14 mm
Z = 4

Data collection

Bruker SMART APEX diffractometer	1387 independent reflections
Radiation source: fine-focus sealed tube	1317 reflections with I > 2σ(I)
graphite	Rint = 0.023
1700 ω scan frames (0.3°, 10)	θmax = 27.5°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −11→11
Tmin = 0.916, Tmax = 0.980	k = −6→6
4852 measured reflections	l = −16→12

Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	0 constraints
R[F2 > 2σ(F2)] = 0.041	H-atom parameters constrained
wR(F2) = 0.107	w = 1/[σ2(Fo2) + (0.0569P)2 + 0.266P] where P = (Fo2 + 2Fc2)/3
S = 1.06	(Δ/σ)max < 0.001
1387 reflections	Δρmax = 0.25 e Å−3
91 parameters	Δρmin = −0.28 e Å−3

Special details

Experimental. Refinement of F2 against unique set of 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 > 2sigma(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.

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 unique set of 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
O1	0.67495 (10)	0.19614 (17)	0.08110 (7)	0.0206 (2)
O2	0.15283 (11)	0.49888 (19)	0.10417 (8)	0.0290 (3)
O3	0.16242 (10)	0.13012 (19)	0.18291 (7)	0.0254 (3)
N1	0.21943 (12)	0.3007 (2)	0.13567 (8)	0.0205 (3)
C1	0.59854 (14)	0.0119 (2)	0.12894 (9)	0.0182 (3)
C2	0.68866 (14)	−0.1941 (2)	0.15531 (9)	0.0202 (3)
H2	0.6627	−0.3465	0.1890	0.024*
C3	0.82904 (14)	−0.1370 (3)	0.12270 (10)	0.0221 (3)
H3	0.9152	−0.2435	0.1300	0.027*
C4	0.81535 (14)	0.0996 (3)	0.07909 (10)	0.0227 (3)
H4	0.8930	0.1870	0.0508	0.027*
C5	0.44755 (13)	0.0618 (2)	0.14455 (9)	0.0185 (3)
H5	0.3974	−0.0667	0.1787	0.022*
C6	0.37162 (14)	0.2755 (3)	0.11477 (10)	0.0197 (3)
H6	0.4172	0.4090	0.0803	0.024*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0179 (4)	0.0200 (5)	0.0243 (5)	0.0009 (3)	0.0046 (3)	0.0019 (3)
O2	0.0269 (5)	0.0301 (5)	0.0303 (5)	0.0112 (4)	0.0053 (4)	0.0047 (4)
O3	0.0206 (5)	0.0269 (5)	0.0299 (5)	−0.0014 (4)	0.0074 (4)	0.0019 (4)
N1	0.0189 (5)	0.0244 (6)	0.0182 (5)	0.0026 (4)	0.0023 (4)	−0.0017 (4)
C1	0.0199 (6)	0.0185 (6)	0.0163 (6)	−0.0013 (4)	0.0027 (4)	−0.0017 (4)
C2	0.0221 (6)	0.0199 (6)	0.0186 (6)	0.0006 (5)	0.0019 (5)	−0.0010 (5)
C3	0.0201 (6)	0.0256 (6)	0.0204 (6)	0.0042 (5)	0.0016 (5)	−0.0025 (5)
C4	0.0164 (6)	0.0279 (7)	0.0242 (6)	0.0007 (5)	0.0040 (5)	−0.0011 (5)
C5	0.0185 (6)	0.0212 (6)	0.0159 (6)	−0.0021 (5)	0.0028 (4)	−0.0023 (4)
C6	0.0170 (6)	0.0236 (6)	0.0194 (6)	0.0002 (5)	0.0052 (4)	−0.0013 (5)

Geometric parameters (Å, °)

O1—C4	1.3680 (15)	C2—H2	0.9500
O1—C1	1.3772 (15)	C3—C4	1.3544 (19)
O2—N1	1.2361 (14)	C3—H3	0.9500
O3—N1	1.2309 (15)	C4—H4	0.9500
N1—C6	1.4428 (16)	C5—C6	1.3366 (18)
C1—C2	1.3623 (17)	C5—H5	0.9500
C1—C5	1.4296 (17)	C6—H6	0.9500
C2—C3	1.4214 (18)
C4—O1—C1	105.97 (10)	C4—C3—H3	126.9
O3—N1—O2	123.33 (11)	C2—C3—H3	126.9
O3—N1—C6	120.08 (11)	C3—C4—O1	111.04 (12)
O2—N1—C6	116.59 (11)	C3—C4—H4	124.5
C2—C1—O1	110.03 (11)	O1—C4—H4	124.5
C2—C1—C5	131.07 (12)	C6—C5—C1	124.94 (12)
O1—C1—C5	118.89 (11)	C6—C5—H5	117.5
C1—C2—C3	106.73 (11)	C1—C5—H5	117.5
C1—C2—H2	126.6	C5—C6—N1	119.11 (12)
C3—C2—H2	126.6	C5—C6—H6	120.4
C4—C3—C2	106.23 (11)	N1—C6—H6	120.4
C4—O1—C1—C2	−0.39 (13)	C1—O1—C4—C3	0.54 (14)
C4—O1—C1—C5	178.58 (10)	C2—C1—C5—C6	179.68 (13)
O1—C1—C2—C3	0.12 (14)	O1—C1—C5—C6	0.96 (18)
C5—C1—C2—C3	−178.69 (12)	C1—C5—C6—N1	−179.91 (11)
C1—C2—C3—C4	0.21 (14)	O3—N1—C6—C5	2.03 (17)
C2—C3—C4—O1	−0.47 (14)	O2—N1—C6—C5	−178.15 (11)