A triclinic polymorph of (E)-2-(2-nitro­ethen­yl)furan

Lin Li; Bo Yu

doi:10.1107/S160053681002492X

. 2010 Jul 3;66(Pt 8):o1914. doi: 10.1107/S160053681002492X

A triclinic polymorph of (E)-2-(2-nitroethenyl)furan

Lin Li ^a,^*, Bo Yu ^a

PMCID: PMC3007394 PMID: 21588246

Abstract

The title compound, C₆H₅NO₃, crystallizes in the triclinic system with six independent molecules in the asymmetric unit. In a previous study, the structure of the title compound was determined in the monoclinic P2₁/n space group at 100 K [Valerga et al. (2009 ▶). Acta Cryst. E65, o1979]. All six independent molecules display an E configuration about the C=C double bond, with the dihedral angles between the planes of the furan rings and the nitroalkenyl groups ranging from 0.61 (7) to 5.03 (7)°. The crystal structure is stabilized by intermolecular C—H⋯O hydrogen-bonding interactions.

Related literature

For the use of nitroalkenes in organic synthesis, see: Ranu et al. (2005 ▶); Ballini & Bosica (2005 ▶); Ono (2005 ▶). For the structure of the monoclinic polymorph, see: Valerga et al. (2009 ▶).

Experimental

Crystal data

C₆H₅NO₃
M _r = 139.11
Triclinic,
a = 9.8407 (14) Å
b = 13.4270 (19) Å
c = 15.300 (2) Å
α = 91.105 (1)°
β = 108.603 (2)°
γ = 91.172 (1)°
V = 1914.8 (5) Å³
Z = 12
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 298 K
0.12 × 0.10 × 0.10 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1997 ▶) T _min = 0.976, T _max = 0.988
13307 measured reflections
8182 independent reflections
4235 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.058
wR(F ²) = 0.149
S = 0.92
8182 reflections
541 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; 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: PLATON.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681002492X/rz2466sup1.cif

e-66-o1914-sup1.cif^{(29.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681002492X/rz2466Isup2.hkl

e-66-o1914-Isup2.hkl^{(400.2KB, hkl)}

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
C1—H1⋯O10ⁱ	0.93	2.58	3.382 (3)	145
C16—H16⋯O13	0.93	2.60	3.370 (3)	141
C26—H26⋯O14ⁱⁱ	0.93	2.59	3.281 (3)	131
C28—H28⋯O8ⁱⁱⁱ	0.93	2.59	3.405 (3)	146
C34—H34⋯O4	0.93	2.59	3.383 (3)	143

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

Financial support of this work by the Natural Science Foundation of Hubei Province(2008CDB036) is greatly appreciated.

supplementary crystallographic information

Comment

Nitroalkenes are good substrates for Michael addition reactions because of the stronger electrowithdrawing property of the nitro group (Ranu et al., 2005). At the same time, the nitro group can provide a good nitrogen source for the synthesis of many useful organic molecules (Ballini & Bosica, 2005; Ono, 2005). Our group focus on new organic transformations obtained by nitroalkene as substrates. In this paper, we report the structure of a triclinic polymorph of the title compound. Recently, the structure of the title compound was determined in the monoclinic P2₁/n space group at 100 K (Valerga et al., 2009).

In the asymmetric unit of the title compound, there are six independent molecules (Fig.1). All molecules display an E configuration about the C═C double bond. Bond lengths and angles are in normal ranges and are comparable with those found in the monoclinic polymorph. The dihedral angles between the planes of the furan rings and the nitroalkenyl groups range from 0.61 (7) to 5.03 (7)°. The crystal structure (Fig. 2) is stabilized by intermolecular C—H···O hydrogen bonding interactions (Table 1).

Experimental

Furfural (0.1 mol) and nitromethane (0.1 mol) were dissolved in 30 ml CH₃OH with stirring under ice bath, and a few ml of a NaOH in CH₃OH solution was added dropwise. After stirring for 1 h, ice water was added and the solution neutralized with a diluted hydrochloric acid solution. The yellowish-brown solid precipitate was filtered and recrystallized from C₂H₅OH (yield 92%). Crystals suitable for X-ray analysis were obtained by slow evaporation of a dichloromethane/hexane (1:1 v/v) solution at 283 K.