(E)-1-Bromo-4-(2-nitro­prop-1-en­yl)benzene

Abstract

The title compound, C₉H₈BrNO₂, which was synthesized by the condensation of 4-bromo­benzaldehyde with nitro­ethane, possesses a trans configuration. The dihedral angle between the benzene ring and the mean plane of the double bond is 7.31 (3)°. The crystal structure is stabilized by short inter­molecular Br⋯O contacts [3.168 (4) Å].

Related literature

For general background to nitro­alkenes as inter­mediates in the preparation of numerous products including insecticides and pharmacologically active substances, see: Boelle et al. (1998 ▶); Vallejos et al. (2005 ▶). For related structures, see: Boys et al. (1993 ▶); Mugnoli et al. (1991 ▶).

Experimental

Crystal data

• C₉H₈BrNO₂

• M _r = 242.07

• Triclinic,

• a = 6.9787 (5) Å

• b = 7.4123 (5) Å

• c = 9.7659 (6) Å

• α = 105.435 (2)°

• β = 95.087 (2)°

• γ = 104.323 (2)°

• V = 465.31 (5) ų

• Z = 2

• Mo Kα radiation

• μ = 4.38 mm⁻¹

• T = 296 K

• 0.21 × 0.19 × 0.08 mm

Data collection

• Rigaku R-AXIS RAPID diffractometer

• Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T _min = 0.388, T _max = 0.703

• 4605 measured reflections

• 2112 independent reflections

• 1303 reflections with I > 2σ(I)

• R _int = 0.027

Refinement

• R[F ² > 2σ(F ²)] = 0.035

• wR(F ²) = 0.094

• S = 1.00

• 2112 reflections

• 120 parameters

• H-atom parameters constrained

• Δρ_max = 0.46 e Å⁻³

• Δρ_min = −0.71 e Å⁻³

Data collection: PROCESS-AUTO (Rigaku, 2006 ▶); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2007 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

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

supplementary crystallographic information

Comment

Nitroalkenes are valuable intermediates for preparation of numerous products including insecticides and pharmacologically active substances (Boelle et al., 1998 and Vallejos et al., 2005) in which the nitro group can be easily transformed into a variety of groups with different functionalities, such as amine, carbonyl groups, etc.. In this article, the crystal structure of the title compound (E)-1-bromo-4-(2-nitroprop-1-enyl)benzene is presented (Fig. 1). The dihedral angle between the benzene ring and the mean plan of the double bond H7/C7/C8/C9 is 7.31 (3) °. The crystal structure is stabilized by short intermolecular Br—O contacts [3.168 (4) Å].

Experimental

To a solution of 4-bromobenzaldehyde (50 mmol) in AcOH (25 ml), nitroethane (75 mmol) was added, followed by butylamine (100 mmol, 7.4 ml). The mixture was sonicated at 333 K, until TLC showed full conversion of aldehyde. The mixture was poured into ice water, the precipitate was filtered off, washed with water and recrystallized from EtOH to give (E)-1-bromo-4-(2-nitroprop-1-enyl)benzene. Suitable crystals of the title compound were obtained by slow evaporation of an ethanol solution at room temperature.

Refinement

All carbon-bonded H atoms were placed in calculated positions with C—H = 0.93 Å (aromatic), C—H = 0.96 Å (sp) and refined using a riding model, with U_iso(H) = 1.2_eq(C).

Figures

Fig. 1.

The asymmetric unit of the title compound (I) with the atomic labeling scheme. Displacement ellipsoids are drawn at the 40% probability level.

Fig. 2.

Molecular packing of the title compound (I) viewed down the a axis.

Crystal data

C9H8BrNO2	Z = 2
Mr = 242.07	F(000) = 240
Triclinic, P1	Dx = 1.728 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.9787 (5) Å	Cell parameters from 3184 reflections
b = 7.4123 (5) Å	θ = 3.1–27.4°
c = 9.7659 (6) Å	µ = 4.38 mm−1
α = 105.435 (2)°	T = 296 K
β = 95.087 (2)°	Platelet, yellow
γ = 104.323 (2)°	0.21 × 0.19 × 0.08 mm
V = 465.31 (5) Å3

Data collection

Rigaku R-AXIS RAPID diffractometer	2112 independent reflections
Radiation source: rolling anode	1303 reflections with I > 2σ(I)
graphite	Rint = 0.027
Detector resolution: 10.00 pixels mm-1	θmax = 27.4°, θmin = 3.1°
ω scans	h = −9→9
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −9→8
Tmin = 0.388, Tmax = 0.703	l = −12→12
4605 measured reflections

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.035	H-atom parameters constrained
wR(F2) = 0.094	w = 1/[σ2(Fo2) + (0.012P)2 + 0.950P] where P = (Fo2 + 2Fc2)/3
S = 1.00	(Δ/σ)max < 0.001
2112 reflections	Δρmax = 0.46 e Å−3
120 parameters	Δρmin = −0.71 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0149 (13)

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
Br1	0.90197 (7)	0.24927 (9)	0.09032 (5)	0.0754 (2)
N1	0.2076 (6)	0.2311 (6)	0.7592 (4)	0.0660 (10)
O1	0.2341 (5)	0.2609 (6)	0.8891 (4)	0.0937 (12)
O2	0.0411 (5)	0.1719 (7)	0.6875 (4)	0.1038 (14)
C8	0.3870 (6)	0.2659 (6)	0.6875 (4)	0.0514 (9)
C1	0.7334 (6)	0.2408 (6)	0.2327 (4)	0.0567 (10)
C5	0.4097 (6)	0.1824 (7)	0.2989 (4)	0.0631 (12)
H5	0.2712	0.1456	0.2720	0.076*
C7	0.3513 (6)	0.2154 (7)	0.5461 (4)	0.0594 (11)
H7	0.2165	0.1633	0.5051	0.071*
C4	0.4907 (6)	0.2283 (6)	0.4430 (4)	0.0524 (10)
C3	0.6976 (6)	0.2770 (8)	0.4767 (5)	0.0776 (15)
H3	0.7569	0.3055	0.5720	0.093*
C9	0.5777 (7)	0.3501 (9)	0.7900 (5)	0.0825 (16)
H9A	0.6349	0.2476	0.7987	0.099*
H9B	0.5528	0.4165	0.8825	0.099*
H9C	0.6694	0.4409	0.7555	0.099*
C2	0.8179 (6)	0.2840 (8)	0.3723 (5)	0.0742 (14)
H2	0.9565	0.3183	0.3976	0.089*
C6	0.5299 (6)	0.1901 (7)	0.1943 (4)	0.0680 (13)
H6	0.4727	0.1609	0.0985	0.082*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Br1	0.0560 (3)	0.1058 (5)	0.0598 (3)	0.0136 (2)	0.0153 (2)	0.0237 (3)
N1	0.055 (2)	0.081 (3)	0.055 (2)	0.0147 (19)	0.0103 (18)	0.014 (2)
O1	0.076 (2)	0.142 (4)	0.056 (2)	0.019 (2)	0.0205 (17)	0.025 (2)
O2	0.0467 (19)	0.173 (4)	0.074 (2)	0.017 (2)	0.0114 (17)	0.020 (2)
C8	0.045 (2)	0.056 (3)	0.050 (2)	0.0112 (18)	0.0092 (17)	0.0142 (19)
C1	0.052 (2)	0.066 (3)	0.052 (2)	0.013 (2)	0.0100 (19)	0.019 (2)
C5	0.042 (2)	0.087 (3)	0.050 (2)	0.012 (2)	−0.0015 (18)	0.012 (2)
C7	0.043 (2)	0.077 (3)	0.051 (2)	0.015 (2)	0.0032 (17)	0.012 (2)
C4	0.042 (2)	0.064 (3)	0.048 (2)	0.0140 (19)	0.0039 (16)	0.013 (2)
C3	0.050 (2)	0.134 (5)	0.044 (2)	0.024 (3)	−0.0013 (19)	0.022 (3)
C9	0.052 (3)	0.122 (5)	0.055 (3)	0.008 (3)	0.003 (2)	0.015 (3)
C2	0.038 (2)	0.123 (4)	0.055 (3)	0.018 (2)	0.0015 (19)	0.022 (3)
C6	0.047 (2)	0.103 (4)	0.045 (2)	0.013 (2)	0.0013 (18)	0.017 (2)

Geometric parameters (Å, °)

Br1—C1	1.902 (4)	C7—C4	1.466 (5)
N1—O2	1.214 (5)	C7—H7	0.9300
N1—O1	1.217 (4)	C4—C3	1.385 (6)
N1—C8	1.488 (5)	C3—C2	1.380 (6)
C8—C7	1.314 (5)	C3—H3	0.9300
C8—C9	1.478 (6)	C9—H9A	0.9600
C1—C2	1.357 (6)	C9—H9B	0.9600
C1—C6	1.366 (6)	C9—H9C	0.9600
C5—C6	1.381 (6)	C2—H2	0.9300
C5—C4	1.388 (5)	C6—H6	0.9300
C5—H5	0.9300
O2—N1—O1	122.1 (4)	C5—C4—C7	117.7 (4)
O2—N1—C8	119.7 (4)	C2—C3—C4	121.6 (4)
O1—N1—C8	118.2 (4)	C2—C3—H3	119.2
C7—C8—C9	130.9 (4)	C4—C3—H3	119.2
C7—C8—N1	115.8 (4)	C8—C9—H9A	109.5
C9—C8—N1	113.2 (3)	C8—C9—H9B	109.5
C2—C1—C6	120.5 (4)	H9A—C9—H9B	109.5
C2—C1—Br1	119.2 (3)	C8—C9—H9C	109.5
C6—C1—Br1	120.3 (3)	H9A—C9—H9C	109.5
C6—C5—C4	121.6 (4)	H9B—C9—H9C	109.5
C6—C5—H5	119.2	C1—C2—C3	119.9 (4)
C4—C5—H5	119.2	C1—C2—H2	120.0
C8—C7—C4	130.1 (4)	C3—C2—H2	120.0
C8—C7—H7	115.0	C1—C6—C5	119.5 (4)
C4—C7—H7	115.0	C1—C6—H6	120.2
C3—C4—C5	116.9 (4)	C5—C6—H6	120.2
C3—C4—C7	125.4 (4)
O2—N1—C8—C7	−4.8 (6)	C8—C7—C4—C5	−173.5 (5)
O1—N1—C8—C7	174.2 (5)	C5—C4—C3—C2	1.5 (8)
O2—N1—C8—C9	176.1 (5)	C7—C4—C3—C2	179.4 (5)
O1—N1—C8—C9	−4.9 (6)	C6—C1—C2—C3	−0.1 (8)
C9—C8—C7—C4	−0.7 (9)	Br1—C1—C2—C3	−179.5 (4)
N1—C8—C7—C4	−179.7 (4)	C4—C3—C2—C1	−0.6 (8)
C6—C5—C4—C3	−1.8 (7)	C2—C1—C6—C5	−0.2 (8)
C6—C5—C4—C7	−179.8 (4)	Br1—C1—C6—C5	179.2 (4)
C8—C7—C4—C3	8.7 (8)	C4—C5—C6—C1	1.1 (8)