2-(3-Methyl-2-nitro­phen­yl)-4,5-dihydro-1,3-oxazole

Abstract

In the title compound, C₁₀H₁₀N₂O₃, an inter­mediate in the synthesis of anthranilamide insecticides, all the non-H atoms except the nitro-group O atom lie on a crystallographic mirror plane. The H atoms of the methyl group are disordered over two sets of sites with equal occupancies. In the crystal structure, C—H⋯N links lead to chains of mol­ecules propagating in [100].

Related literature

For background to anthranilamide compounds, a new class of inseticides, see: Lahm et al. (2003 ▶, 2005 ▶).

Experimental

Crystal data

• C₁₀H₁₀N₂O₃

• M _r = 206.20

• Monoclinic,

• a = 7.7767 (10) Å

• b = 7.3370 (10) Å

• c = 8.6468 (12) Å

• β = 99.414 (2)°

• V = 486.72 (11) ų

• Z = 2

• Mo Kα radiation

• μ = 0.11 mm⁻¹

• T = 296 (2) K

• 0.24 × 0.22 × 0.18 mm

Data collection

• Bruker SMART CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.834, T _max = 1.000 (expected range = 0.818–0.981)

• 2462 measured reflections

• 937 independent reflections

• 842 reflections with I > 2σ(I)

• R _int = 0.011

Refinement

• R[F ² > 2σ(F ²)] = 0.037

• wR(F ²) = 0.110

• S = 1.07

• 937 reflections

• 90 parameters

• H-atom parameters constrained

• Δρ_max = 0.17 e Å⁻³

• Δρ_min = −0.15 e Å⁻³

Data collection: SMART (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; 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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4⋯N1i	0.93	2.60	3.508 (3)	167

Symmetry code: (i) .

supplementary crystallographic information

Comment

Anthranilamide compounds as a new class of inseticides are characterized by their high levels of insecticidal activity, no-cross resistance to existing insecticides, safety to off-target animal and low toxicity to mammals (Lahm et al. 2003, 2005)

The title compound (I) as an intermediate for preparing Chlorantraniliprole analogs plays an important role in identifying the configuration of two possible products.

In the molecular structure of (I), (Fig. 1) all the non-hydrogen atoms except the nitro-group O atom lie on a crystallographic mirror plane. In the crystal, C—H···N links lead to chains of molecules propagating in [100].

Experimental

2-Bromoethanamine hydrobromide (10.25 g, 50 mmol) and 3-methyl-2-nitrobenzoyl chloride (9.98 g, 50 mmol) were added into dichloromethane (200 ml), then triethylamine (16.70 g, 165 mmol) was added. The mixture was heated to reflux for 14 h and cooled down to room temperature, washed with water and brine, dried by anhydrous sulfate magnesium, then evaporated to give the title compound as a white solid. The product was dissolved in dichloromethane and left to stand at room temperature and colourless blocks of (I) were obtained.

Anal. Calcd for C₁₀H₁₀N₂O₃: C, 58.25; H, 4.89; N, 13.59; O, 23.28. Found: C, 58.20; H, 4.90; N, 13.61; O, 23.25 ¹H NMR(CDCl₃): 2.35 (s, 3H, CH₃), 4.06 (t, J=9.8 Hz, 2H, CH₂), 4.40 (t, J=9.6 Hz, 2H, CH₂), 7.41–7.43(m, 2H), 7.78–7.81 (m, 1H).

Refinement

Although all H atoms were visible in difference maps, they were finally placed in geometrically calculated positions, with C—H distances in the range 0.93–0.96 Å, and included in the final refinement in the riding model approximation, with U_iso(H) = 1.2U_eq(C) for aromatic and U_iso(H) = 1.5U_eq(C) for methyl H atoms.

Figures

Fig. 1.

The molecular structure of (I), with 30% probability displacement ellipsoids for the non-hydrogen atoms. Symmetry code: A x, 1/2–y, z.

Crystal data

C10H10N2O3	F(000) = 216
Mr = 206.20	Dx = 1.407 Mg m−3
Monoclinic, P21/m	Mo Kα radiation, λ = 0.71073 Å
a = 7.7767 (10) Å	Cell parameters from 1713 reflections
b = 7.337 (1) Å	θ = 2.7–27.9°
c = 8.6468 (12) Å	µ = 0.11 mm−1
β = 99.414 (2)°	T = 296 K
V = 486.72 (11) Å3	BLOCK, colourless
Z = 2	0.24 × 0.22 × 0.18 mm

Data collection

Bruker SMART CCD diffractometer	937 independent reflections
Radiation source: fine-focus sealed tube	842 reflections with I > 2σ(I)
graphite	Rint = 0.011
ω scans	θmax = 25.0°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −9→9
Tmin = 0.834, Tmax = 1.000	k = −6→8
2462 measured reflections	l = −10→9

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.110	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.0583P)2 + 0.1052P] where P = (Fo2 + 2Fc2)/3
937 reflections	(Δ/σ)max < 0.001
90 parameters	Δρmax = 0.17 e Å−3
0 restraints	Δρmin = −0.15 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	Occ. (<1)
O1	0.2190 (2)	0.2500	1.12373 (17)	0.0794 (6)
O2	0.33918 (12)	0.10351 (17)	0.61731 (13)	0.0628 (4)
N1	0.4057 (2)	0.2500	0.95534 (19)	0.0617 (6)
N2	0.27535 (19)	0.2500	0.64083 (17)	0.0428 (4)
C1	−0.0249 (3)	0.2500	0.4054 (2)	0.0520 (5)
H1A	0.0705	0.3268	0.3893	0.078*	0.50
H1B	−0.1309	0.2952	0.3449	0.078*	0.50
H1C	−0.0041	0.1280	0.3728	0.078*	0.50
C2	−0.0410 (2)	0.2500	0.5759 (2)	0.0430 (5)
C3	−0.2030 (3)	0.2500	0.6245 (3)	0.0533 (5)
H3	−0.3034	0.2500	0.5495	0.064*
C4	−0.2181 (3)	0.2500	0.7801 (3)	0.0630 (6)
H4	−0.3281	0.2500	0.8092	0.076*
C5	−0.0709 (3)	0.2500	0.8946 (3)	0.0589 (6)
H5	−0.0828	0.2500	0.9998	0.071*
C6	0.0946 (2)	0.2500	0.8531 (2)	0.0434 (5)
C7	0.1040 (2)	0.2500	0.6938 (2)	0.0381 (4)
C8	0.2508 (2)	0.2500	0.9762 (2)	0.0428 (5)
C9	0.3878 (3)	0.2500	1.2242 (3)	0.0671 (7)
H9	0.4021	0.1424	1.2902	0.081*
C10	0.5156 (3)	0.2500	1.1111 (2)	0.0580 (6)
H10	0.5890	0.3576	1.1251	0.070*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0487 (9)	0.1510 (17)	0.0384 (8)	0.000	0.0066 (7)	0.000
O2	0.0475 (6)	0.0714 (8)	0.0701 (8)	0.0137 (5)	0.0117 (5)	−0.0128 (5)
N1	0.0353 (9)	0.1100 (16)	0.0376 (9)	0.000	−0.0005 (7)	0.000
N2	0.0323 (8)	0.0582 (10)	0.0363 (8)	0.000	0.0013 (6)	0.000
C1	0.0451 (11)	0.0637 (13)	0.0437 (11)	0.000	−0.0033 (8)	0.000
C2	0.0358 (10)	0.0443 (10)	0.0463 (10)	0.000	−0.0010 (8)	0.000
C3	0.0316 (9)	0.0658 (13)	0.0594 (13)	0.000	−0.0020 (8)	0.000
C4	0.0322 (10)	0.0932 (17)	0.0649 (14)	0.000	0.0114 (9)	0.000
C5	0.0397 (11)	0.0885 (16)	0.0505 (12)	0.000	0.0130 (9)	0.000
C6	0.0347 (10)	0.0516 (11)	0.0434 (10)	0.000	0.0046 (8)	0.000
C7	0.0290 (8)	0.0422 (10)	0.0428 (10)	0.000	0.0047 (7)	0.000
C8	0.0408 (10)	0.0521 (11)	0.0352 (9)	0.000	0.0057 (7)	0.000
C9	0.0550 (13)	0.1013 (19)	0.0413 (11)	0.000	−0.0030 (10)	0.000
C10	0.0445 (11)	0.0834 (16)	0.0418 (11)	0.000	−0.0058 (8)	0.000

Geometric parameters (Å, °)

O1—C8	1.339 (2)	C3—C4	1.370 (3)
O1—C9	1.451 (3)	C3—H3	0.9300
O2—N2	1.2149 (13)	C4—C5	1.385 (3)
N1—C8	1.247 (2)	C4—H4	0.9300
N1—C10	1.472 (2)	C5—C6	1.391 (3)
N2—O2i	1.2149 (13)	C5—H5	0.9300
N2—C7	1.478 (2)	C6—C7	1.391 (3)
C1—C2	1.501 (3)	C6—C8	1.478 (3)
C1—H1A	0.9600	C9—C10	1.504 (3)
C1—H1B	0.9600	C9—H9	0.9700
C1—H1C	0.9600	C9—H9i	0.9700
C2—C7	1.391 (2)	C10—H10	0.9700
C2—C3	1.391 (3)	C10—H10i	0.9700
C8—O1—C9	106.31 (16)	C6—C5—H5	119.8
C8—N1—C10	107.34 (17)	C7—C6—C5	117.07 (18)
O2i—N2—O2	124.43 (16)	C7—C6—C8	122.89 (17)
O2i—N2—C7	117.75 (8)	C5—C6—C8	120.04 (18)
O2—N2—C7	117.75 (8)	C2—C7—C6	123.93 (17)
C2—C1—H1A	109.5	C2—C7—N2	115.90 (16)
C2—C1—H1B	109.5	C6—C7—N2	120.18 (15)
H1A—C1—H1B	109.5	N1—C8—O1	118.10 (17)
C2—C1—H1C	109.5	N1—C8—C6	126.55 (17)
H1A—C1—H1C	109.5	O1—C8—C6	115.35 (16)
H1B—C1—H1C	109.5	O1—C9—C10	103.87 (16)
C7—C2—C3	116.38 (18)	O1—C9—H9	111.0
C7—C2—C1	122.16 (17)	C10—C9—H9i	111.0
C3—C2—C1	121.46 (17)	O1—C9—H9i	111.0
C4—C3—C2	121.60 (18)	C10—C9—H9i	111.0
C4—C3—H3	119.2	H9—C9—H9i	109.0
C2—C3—H3	119.2	N1—C10—C9	104.38 (16)
C3—C4—C5	120.52 (19)	N1—C10—H10	110.9
C3—C4—H4	119.7	C9—C10—H10	110.9
C5—C4—H4	119.7	N1—C10—H10i	110.9
C4—C5—C6	120.5 (2)	C9—C10—H10i	110.9
C4—C5—H5	119.8	H10—C10—H10i	108.9
C7—C2—C3—C4	0.0	O2—N2—C7—C2	−88.46 (13)
C1—C2—C3—C4	180.0	O2i—N2—C7—C6	−91.54 (13)
C2—C3—C4—C5	0.0	O2—N2—C7—C6	91.54 (13)
C3—C4—C5—C6	0.0	C10—N1—C8—O1	0.0
C4—C5—C6—C7	0.0	C10—N1—C8—C6	180.0
C4—C5—C6—C8	180.0	C9—O1—C8—N1	0.0
C3—C2—C7—C6	0.0	C9—O1—C8—C6	180.0
C1—C2—C7—C6	180.0	C7—C6—C8—N1	0.0
C3—C2—C7—N2	180.0	C5—C6—C8—N1	180.0
C1—C2—C7—N2	0.0	C7—C6—C8—O1	180.0
C5—C6—C7—C2	0.0	C5—C6—C8—O1	0.0
C8—C6—C7—C2	180.0	C8—O1—C9—C10	0.0
C5—C6—C7—N2	180.0	C8—N1—C10—C9	0.0
C8—C6—C7—N2	0.0	O1—C9—C10—N1	0.0
O2i—N2—C7—C2	88.46 (13)

Symmetry codes: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···N1ii	0.93	2.60	3.508 (3)	167

Symmetry codes: (ii) x−1, y, z.