2-Methyl-7-nitro-2,3-dihydro-1-benzofuran

Abstract

The dihydro­furan ring of the title compound, C₉H₉NO₃, adopts an envelope conformation. The nitro group is twisted slightly away from the attached benzene ring [dihedral angle = 21.9 (1)°].

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For details of the synthesis, see: Majumdar et al. (2008 ▶).

Experimental

Crystal data

• C₉H₉NO₃

• M _r = 179.17

• Orthorhombic,

• a = 8.4250 (17) Å

• b = 7.2260 (14) Å

• c = 28.295 (6) Å

• V = 1722.6 (6) ų

• Z = 8

• Mo Kα radiation

• μ = 0.10 mm⁻¹

• T = 298 (2) K

• 0.30 × 0.20 × 0.20 mm

Data collection

• Enraf–Nonius CAD-4 diffractometer

• Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.969, T _max = 0.979

• 2977 measured reflections

• 1551 independent reflections

• 829 reflections with I > 2σ(I)

• R _int = 0.048

• 3 standard reflections every 200 reflections intensity decay: none

Refinement

• R[F ² > 2σ(F ²)] = 0.066

• wR(F ²) = 0.182

• S = 1.01

• 1551 reflections

• 118 parameters

• H-atom parameters constrained

• Δρ_max = 0.32 e Å⁻³

• Δρ_min = −0.26 e Å⁻³

Data collection: CAD-4 Software (Enraf–Nonius, 1985 ▶); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

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

supplementary crystallographic information

Comment

The tittle compound, 2-methyl-7-nitro-2,3-dihydrobenzofuran, is an important intermediate for the synthesis of 2-methyl-2,3-dihydrobenzofuran-7-amine. we report here the crystal structure of the title compound.

The molecular structure of the compound is shown in Fig. 1. Bond lengths and angles are within normal ranges (Allen et al., 1987), except the C1—C2 bond length of 1.420 (6) Å. The dihydrofuran ring is in an envelope conformation with C2 as flap atom. The nitro group is slightly twisted away from the attached benzene ring [O2—N—C8—C9 = 5.3 (5)° and O3—N—C8—C7 = 5.9 (5)°]. No hydrogen bonding interactions are observed in the crystal structure (Fig.2).

Experimental

The title compound was synthesized according to the literature method (Majumdar et al., 2008). Single crystals were obtained by slow evaporation of a methanol (25 ml) solution of the compound (0.30 g, 1.6 mmol) at room temperature for about 4 d.

Refinement

H atoms were positioned geometrically [C-H = 0.93-0.98 Å] and constrained to ride on their parent atoms, with U_iso(H) = xU_eq(C), where x = 1.2 for aromatic and methylene H and 1.5 for methyl H atoms.

Figures

Fig. 1.

The molecular structure of the title compound, showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 40% probability level.

Fig. 2.

A view of the molecular packing in the title compound.

Crystal data

C9H9NO3	F000 = 752
Mr = 179.17	Dx = 1.382 Mg m−3
Orthorhombic, Pbca	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 25 reflections
a = 8.4250 (17) Å	θ = 10–13º
b = 7.2260 (14) Å	µ = 0.11 mm−1
c = 28.295 (6) Å	T = 298 (2) K
V = 1722.6 (6) Å3	Block, colourless
Z = 8	0.30 × 0.20 × 0.20 mm

Data collection

Enraf–Nonius CAD-4 diffractometer	Rint = 0.048
Radiation source: fine-focus sealed tube	θmax = 25.2º
Monochromator: graphite	θmin = 1.4º
T = 298(2) K	h = 0→10
ω/2θ scans	k = −8→8
Absorption correction: ψ scan(North et al., 1968)	l = 0→33
Tmin = 0.969, Tmax = 0.979	3 standard reflections
2977 measured reflections	every 200 reflections
1551 independent reflections	intensity decay: none
829 reflections with I > 2σ(I)

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)] = 0.066	H-atom parameters constrained
wR(F2) = 0.182	w = 1/[σ2(Fo2) + (0.06P)2 + 1.5P] where P = (Fo2 + 2Fc2)/3
S = 1.01	(Δ/σ)max = 0.001
1551 reflections	Δρmax = 0.32 e Å−3
118 parameters	Δρmin = −0.26 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

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
N	0.5181 (3)	0.0623 (5)	0.39917 (10)	0.0581 (8)
O1	0.2624 (3)	0.0149 (4)	0.32787 (7)	0.0601 (8)
C1	0.1077 (6)	0.0403 (8)	0.25775 (16)	0.0970 (16)
H1A	0.1909	−0.0204	0.2405	0.146*
H1B	0.1258	0.1715	0.2576	0.146*
H1C	0.0074	0.0140	0.2431	0.146*
O2	0.5612 (3)	0.0409 (5)	0.35839 (9)	0.0867 (10)
C2	0.1064 (4)	−0.0249 (8)	0.30507 (14)	0.0812 (14)
H2A	0.0947	−0.1598	0.3038	0.097*
O3	0.6098 (3)	0.0689 (6)	0.43222 (10)	0.0992 (12)
C3	−0.0172 (4)	0.0473 (6)	0.33963 (14)	0.0706 (11)
H3A	−0.0614	0.1638	0.3289	0.085*
H3B	−0.1025	−0.0413	0.3438	0.085*
C4	0.0753 (4)	0.0725 (5)	0.38480 (12)	0.0532 (9)
C5	0.0285 (4)	0.1112 (5)	0.42971 (13)	0.0634 (10)
H5A	−0.0788	0.1240	0.4368	0.076*
C6	0.1416 (5)	0.1314 (6)	0.46479 (13)	0.0624 (10)
H6A	0.1093	0.1557	0.4956	0.075*
C7	0.3000 (4)	0.1164 (5)	0.45498 (12)	0.0560 (9)
H7A	0.3747	0.1319	0.4789	0.067*
C8	0.3491 (4)	0.0774 (5)	0.40863 (11)	0.0460 (8)
C9	0.2360 (4)	0.0537 (4)	0.37377 (11)	0.0459 (8)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N	0.0376 (15)	0.085 (2)	0.0513 (17)	−0.0068 (16)	−0.0090 (16)	0.0044 (16)
O1	0.0358 (11)	0.104 (2)	0.0411 (12)	0.0006 (13)	−0.0058 (12)	−0.0061 (12)
C1	0.066 (3)	0.151 (5)	0.074 (3)	−0.004 (3)	−0.022 (3)	0.017 (3)
O2	0.0389 (13)	0.168 (3)	0.0530 (16)	0.0016 (17)	0.0045 (13)	−0.0016 (17)
C2	0.047 (2)	0.134 (4)	0.063 (2)	−0.004 (2)	−0.014 (2)	−0.002 (3)
O3	0.0446 (15)	0.176 (3)	0.0773 (19)	−0.0046 (19)	−0.0248 (16)	−0.009 (2)
C3	0.0399 (19)	0.098 (3)	0.074 (3)	−0.003 (2)	−0.009 (2)	−0.002 (2)
C4	0.0313 (16)	0.070 (2)	0.058 (2)	0.0012 (16)	0.0062 (16)	0.0053 (18)
C5	0.044 (2)	0.069 (3)	0.077 (3)	0.0068 (18)	0.009 (2)	0.004 (2)
C6	0.069 (2)	0.073 (2)	0.0458 (19)	0.006 (2)	0.011 (2)	−0.0021 (18)
C7	0.060 (2)	0.061 (2)	0.047 (2)	−0.0053 (19)	−0.0032 (18)	0.0004 (17)
C8	0.0352 (17)	0.060 (2)	0.0426 (18)	−0.0023 (15)	−0.0007 (15)	0.0044 (16)
C9	0.0375 (16)	0.0554 (19)	0.0447 (17)	−0.0043 (15)	−0.0028 (16)	0.0030 (16)

Geometric parameters (Å, °)

N—O3	1.214 (4)	C3—H3A	0.97
N—O2	1.219 (3)	C3—H3B	0.97
N—C8	1.453 (4)	C4—C5	1.360 (5)
O1—C9	1.347 (4)	C4—C9	1.396 (4)
O1—C2	1.492 (4)	C5—C6	1.384 (5)
C1—C2	1.420 (6)	C5—H5A	0.93
C1—H1A	0.96	C6—C7	1.367 (5)
C1—H1B	0.96	C6—H6A	0.93
C1—H1C	0.96	C7—C8	1.404 (4)
C2—C3	1.520 (6)	C7—H7A	0.93
C2—H2A	0.98	C8—C9	1.382 (4)
C3—C4	1.508 (5)
O3—N—O2	123.0 (3)	C2—C3—H3B	111.1
O3—N—C8	118.6 (3)	H3A—C3—H3B	109.0
O2—N—C8	118.4 (3)	C5—C4—C9	120.7 (3)
C9—O1—C2	108.2 (3)	C5—C4—C3	131.8 (3)
C2—C1—H1A	109.5	C9—C4—C3	107.5 (3)
C2—C1—H1B	109.5	C4—C5—C6	119.5 (3)
H1A—C1—H1B	109.5	C4—C5—H5A	120.3
C2—C1—H1C	109.5	C6—C5—H5A	120.3
H1A—C1—H1C	109.5	C7—C6—C5	121.2 (3)
H1B—C1—H1C	109.5	C7—C6—H6A	119.4
C1—C2—O1	109.7 (4)	C5—C6—H6A	119.4
C1—C2—C3	119.9 (4)	C6—C7—C8	119.6 (3)
O1—C2—C3	105.0 (3)	C6—C7—H7A	120.2
C1—C2—H2A	107.2	C8—C7—H7A	120.2
O1—C2—H2A	107.2	C9—C8—C7	119.2 (3)
C3—C2—H2A	107.2	C9—C8—N	122.3 (3)
C4—C3—C2	103.5 (3)	C7—C8—N	118.4 (3)
C4—C3—H3A	111.1	O1—C9—C8	126.9 (3)
C2—C3—H3A	111.1	O1—C9—C4	113.3 (3)
C4—C3—H3B	111.1	C8—C9—C4	119.8 (3)
C9—O1—C2—C1	145.4 (4)	O2—N—C8—C9	5.3 (5)
C9—O1—C2—C3	15.4 (4)	O3—N—C8—C7	5.9 (5)
C1—C2—C3—C4	−139.3 (4)	O2—N—C8—C7	−175.1 (3)
O1—C2—C3—C4	−15.5 (5)	C2—O1—C9—C8	172.0 (4)
C2—C3—C4—C5	−170.7 (4)	C2—O1—C9—C4	−8.9 (4)
C2—C3—C4—C9	10.9 (5)	C7—C8—C9—O1	−179.7 (3)
C9—C4—C5—C6	−0.2 (6)	N—C8—C9—O1	0.0 (6)
C3—C4—C5—C6	−178.4 (4)	C7—C8—C9—C4	1.3 (5)
C4—C5—C6—C7	1.2 (6)	N—C8—C9—C4	−179.1 (3)
C5—C6—C7—C8	−0.8 (6)	C5—C4—C9—O1	179.8 (3)
C6—C7—C8—C9	−0.4 (5)	C3—C4—C9—O1	−1.6 (4)
C6—C7—C8—N	180.0 (3)	C5—C4—C9—C8	−1.0 (6)
O3—N—C8—C9	−173.7 (3)	C3—C4—C9—C8	177.6 (3)