3,4-Dimethyl-N-[(E)-3-nitro­benzyl­idene]-1,2-oxazol-5-amine

Abstract

In the title compound, C₁₂H₁₁N₃O₃, the dihedral angle between the 3-nitro­benzaldehyde and 5-amino-3,4-dimethyl-1,2-oxazole moieties is 2.46 (12)°. The mol­ecule is close to planar, the r.m.s. deviation for the non-H atoms being 0.028 Å. The packing only features van der Waals inter­actions between the mol­ecules.

Related literature

For background and related crystal structures, see: Asiri et al. (2010a ▶,b ▶,c ▶,d ▶).

Experimental

Crystal data

• C₁₂H₁₁N₃O₃

• M _r = 245.24

• Monoclinic,

• a = 12.602 (2) Å

• b = 3.9267 (6) Å

• c = 23.366 (4) Å

• β = 94.791 (9)°

• V = 1152.3 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 0.11 mm⁻¹

• T = 296 K

• 0.22 × 0.08 × 0.06 mm

Data collection

• Bruker Kappa APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.992, T _max = 0.995

• 8616 measured reflections

• 2046 independent reflections

• 846 reflections with I > 2σ(I)

• R _int = 0.097

Refinement

• R[F ² > 2σ(F ²)] = 0.061

• wR(F ²) = 0.161

• S = 0.99

• 2046 reflections

• 166 parameters

• H-atom parameters constrained

• Δρ_max = 0.16 e Å⁻³

• Δρ_min = −0.19 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

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

supplementary crystallographic information

Comment

The title compound (I, Fig. 1) is being reported in continuation of our synthetic and structural studies of various Schiff bases of 5-amino-3,4-dimethylisoxazole (Asiri et al., 2010a, b, c, d).

In (I), the 3-nitrobenzaldehyde moiety A (C1—C7/N1/O1/O2) and 5-amino-3,4-dimethylisoxazole moiety B (N2/C8—C12/N3/O3) are planar with r. m. s. deviation of 0.0124 and 0.0099 Å, respectively. The dihedral angle between A/B is 2.46 (12)°. All the heavy atoms (C1—C12/N1—N3/O1—O3) consituate plane with r. m. s. deviation of 0.0276 Å. In this plane, the methyl atom C12 deviates at the maximum with 0.0721 (33) Å. The title compound essentially consists of monomers. There exists no π···π interactions in the crystal.

Experimental

A mixture of 4-nitrobenzaldehyde (0.33 g, 2.2 mmol) and 5-amino-3,4-dimethylisoxazole (0.24 g, 2.2 mmol) in ethanol (15 ml) was refluxed for 5 h with stirring to give a light yellow precipitate. This material was filtered off and washed with ethanol to give long thin needles of (I).

Yield: 56.45%; m.p. 463–464 K.

IR (KBr) \v_max cm^-1: 3069 (C—H for CH₃), 2922 (C—H), 1568 (C═C), 1523 (C═N), 1162 (C—N).

Refinement

The H-atoms were positioned geometrically (C–H = 0.93–0.96 Å) and refined as riding with U_iso(H) = xU_eq(C), where x = 1.5 for methyl and x = 1.2 for other H-atoms.

Figures

Fig. 1.

View of (I) with displacement ellipsoids drawn at the 50% probability level.

Crystal data

C12H11N3O3	F(000) = 512
Mr = 245.24	Dx = 1.414 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 846 reflections
a = 12.602 (2) Å	θ = 2.3–25.0°
b = 3.9267 (6) Å	µ = 0.11 mm−1
c = 23.366 (4) Å	T = 296 K
β = 94.791 (9)°	Needle, colorless
V = 1152.3 (3) Å3	0.22 × 0.08 × 0.06 mm
Z = 4

Data collection

Bruker Kappa APEXII CCD diffractometer	2046 independent reflections
Radiation source: fine-focus sealed tube	846 reflections with I > 2σ(I)
graphite	Rint = 0.097
Detector resolution: 8.20 pixels mm-1	θmax = 25.0°, θmin = 2.3°
ω scans	h = −15→15
Absorption correction: multi-scan (SADABS; Bruker, 2005)	k = −4→4
Tmin = 0.992, Tmax = 0.995	l = −27→27
8616 measured reflections

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)] = 0.061	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.161	H-atom parameters constrained
S = 0.99	w = 1/[σ2(Fo2) + (0.0341P)2] where P = (Fo2 + 2Fc2)/3
2046 reflections	(Δ/σ)max < 0.001
166 parameters	Δρmax = 0.16 e Å−3
0 restraints	Δρmin = −0.19 e Å−3

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
O1	0.0661 (2)	0.9618 (9)	0.11316 (16)	0.0932 (16)
O2	0.0217 (3)	0.7756 (9)	0.19373 (16)	0.1103 (19)
O3	0.5961 (2)	0.7628 (6)	0.02581 (12)	0.0630 (11)
N1	0.0873 (3)	0.8153 (10)	0.15894 (19)	0.0708 (17)
N2	0.5490 (3)	0.5694 (8)	0.11691 (13)	0.0523 (12)
N3	0.6882 (3)	0.7702 (8)	−0.00509 (15)	0.0660 (17)
C1	0.3736 (3)	0.6218 (9)	0.14659 (17)	0.0475 (17)
C2	0.3985 (3)	0.4605 (10)	0.19866 (18)	0.0579 (17)
C3	0.3218 (4)	0.4146 (10)	0.23763 (18)	0.0629 (17)
C4	0.2194 (4)	0.5255 (10)	0.22380 (19)	0.0618 (17)
C5	0.1954 (3)	0.6856 (10)	0.17248 (19)	0.0534 (17)
C6	0.2697 (3)	0.7379 (9)	0.13294 (17)	0.0511 (17)
C7	0.4530 (3)	0.6720 (9)	0.10518 (17)	0.0527 (17)
C8	0.6232 (3)	0.6142 (10)	0.07766 (17)	0.0521 (17)
C9	0.7266 (3)	0.5238 (9)	0.08165 (17)	0.0485 (17)
C10	0.7629 (3)	0.6275 (9)	0.02938 (19)	0.0513 (17)
C11	0.8723 (3)	0.5881 (10)	0.00968 (19)	0.0727 (19)
C12	0.7889 (3)	0.3614 (10)	0.13104 (17)	0.0672 (17)
H2	0.46743	0.38159	0.20778	0.0695*
H3	0.33974	0.30952	0.27277	0.0758*
H4	0.16713	0.49195	0.24908	0.0742*
H6	0.25095	0.84733	0.09826	0.0611*
H7	0.43386	0.77846	0.07029	0.0629*
H11A	0.87321	0.67477	−0.02869	0.1088*
H11B	0.89153	0.35146	0.01024	0.1088*
H11C	0.92235	0.71279	0.03486	0.1088*
H12A	0.82773	0.53290	0.15333	0.1006*
H12B	0.83789	0.20017	0.11712	0.1006*
H12C	0.74137	0.24627	0.15460	0.1006*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.064 (2)	0.141 (3)	0.074 (3)	0.0185 (19)	0.003 (2)	0.011 (2)
O2	0.066 (3)	0.170 (4)	0.100 (3)	0.011 (2)	0.037 (2)	0.017 (2)
O3	0.0537 (19)	0.084 (2)	0.051 (2)	0.0055 (14)	0.0022 (15)	0.0092 (15)
N1	0.057 (3)	0.097 (3)	0.059 (3)	0.002 (2)	0.009 (2)	−0.011 (2)
N2	0.048 (2)	0.061 (2)	0.048 (2)	−0.0018 (17)	0.0047 (18)	−0.0012 (16)
N3	0.065 (3)	0.080 (3)	0.054 (3)	−0.001 (2)	0.011 (2)	0.0068 (19)
C1	0.050 (3)	0.047 (3)	0.045 (3)	−0.0016 (19)	0.001 (2)	−0.005 (2)
C2	0.052 (3)	0.068 (3)	0.053 (3)	−0.001 (2)	0.000 (2)	−0.010 (2)
C3	0.073 (3)	0.071 (3)	0.045 (3)	−0.003 (2)	0.006 (3)	−0.003 (2)
C4	0.065 (3)	0.073 (3)	0.049 (3)	−0.007 (2)	0.014 (2)	−0.010 (2)
C5	0.046 (3)	0.059 (3)	0.054 (3)	−0.006 (2)	−0.002 (2)	−0.013 (2)
C6	0.050 (3)	0.058 (3)	0.045 (3)	−0.0016 (19)	0.003 (2)	−0.005 (2)
C7	0.049 (3)	0.065 (3)	0.044 (3)	−0.001 (2)	0.004 (2)	0.000 (2)
C8	0.056 (3)	0.056 (3)	0.043 (3)	−0.001 (2)	−0.003 (2)	0.003 (2)
C9	0.042 (3)	0.055 (3)	0.048 (3)	0.001 (2)	0.001 (2)	−0.003 (2)
C10	0.049 (3)	0.053 (3)	0.052 (3)	0.001 (2)	0.004 (2)	−0.005 (2)
C11	0.063 (3)	0.079 (3)	0.079 (4)	0.000 (2)	0.024 (3)	0.000 (3)
C12	0.064 (3)	0.078 (3)	0.059 (3)	0.010 (2)	0.002 (2)	0.002 (2)

Geometric parameters (Å, °)

O1—N1	1.224 (6)	C8—C9	1.346 (5)
O2—N1	1.217 (6)	C9—C10	1.400 (6)
O3—N3	1.418 (5)	C9—C12	1.484 (5)
O3—C8	1.362 (5)	C10—C11	1.498 (5)
N1—C5	1.464 (5)	C2—H2	0.9300
N2—C7	1.283 (5)	C3—H3	0.9300
N2—C8	1.375 (5)	C4—H4	0.9300
N3—C10	1.312 (5)	C6—H6	0.9300
C1—C2	1.384 (6)	C7—H7	0.9300
C1—C6	1.398 (5)	C11—H11A	0.9600
C1—C7	1.462 (5)	C11—H11B	0.9600
C2—C3	1.394 (6)	C11—H11C	0.9600
C3—C4	1.375 (7)	C12—H12A	0.9600
C4—C5	1.365 (6)	C12—H12B	0.9600
C5—C6	1.385 (6)	C12—H12C	0.9600
N3—O3—C8	107.9 (3)	N3—C10—C11	119.2 (4)
O1—N1—O2	122.2 (4)	C9—C10—C11	127.9 (4)
O1—N1—C5	118.9 (4)	C1—C2—H2	120.00
O2—N1—C5	118.9 (4)	C3—C2—H2	120.00
C7—N2—C8	120.0 (3)	C2—C3—H3	120.00
O3—N3—C10	104.8 (3)	C4—C3—H3	120.00
C2—C1—C6	119.3 (4)	C3—C4—H4	120.00
C2—C1—C7	121.7 (3)	C5—C4—H4	120.00
C6—C1—C7	119.0 (3)	C1—C6—H6	121.00
C1—C2—C3	121.0 (4)	C5—C6—H6	121.00
C2—C3—C4	119.6 (4)	N2—C7—H7	120.00
C3—C4—C5	119.2 (4)	C1—C7—H7	120.00
N1—C5—C4	118.9 (4)	C10—C11—H11A	109.00
N1—C5—C6	118.2 (4)	C10—C11—H11B	109.00
C4—C5—C6	122.8 (4)	C10—C11—H11C	109.00
C1—C6—C5	118.2 (4)	H11A—C11—H11B	109.00
N2—C7—C1	120.1 (3)	H11A—C11—H11C	109.00
O3—C8—N2	120.9 (3)	H11B—C11—H11C	109.00
O3—C8—C9	110.1 (3)	C9—C12—H12A	109.00
N2—C8—C9	128.9 (4)	C9—C12—H12B	109.00
C8—C9—C10	104.4 (3)	C9—C12—H12C	109.00
C8—C9—C12	127.8 (4)	H12A—C12—H12B	109.00
C10—C9—C12	127.8 (3)	H12A—C12—H12C	109.00
N3—C10—C9	112.9 (3)	H12B—C12—H12C	109.00
C8—O3—N3—C10	0.2 (4)	C7—C1—C6—C5	179.5 (3)
N3—O3—C8—C9	−0.5 (4)	C2—C1—C7—N2	−0.9 (6)
N3—O3—C8—N2	−179.4 (3)	C1—C2—C3—C4	1.2 (6)
O2—N1—C5—C4	−0.3 (6)	C2—C3—C4—C5	−1.4 (6)
O2—N1—C5—C6	−178.9 (4)	C3—C4—C5—N1	−177.6 (4)
O1—N1—C5—C4	179.3 (4)	C3—C4—C5—C6	0.9 (6)
O1—N1—C5—C6	0.7 (6)	N1—C5—C6—C1	178.4 (3)
C7—N2—C8—C9	−179.6 (4)	C4—C5—C6—C1	−0.2 (6)
C8—N2—C7—C1	179.4 (3)	O3—C8—C9—C10	0.5 (4)
C7—N2—C8—O3	−0.9 (5)	N2—C8—C9—C12	−2.5 (7)
O3—N3—C10—C11	179.1 (3)	O3—C8—C9—C12	178.7 (3)
O3—N3—C10—C9	0.1 (4)	N2—C8—C9—C10	179.4 (4)
C6—C1—C2—C3	−0.4 (6)	C8—C9—C10—N3	−0.4 (4)
C7—C1—C2—C3	−180.0 (4)	C12—C9—C10—C11	2.5 (6)
C6—C1—C7—N2	179.6 (3)	C8—C9—C10—C11	−179.3 (4)
C2—C1—C6—C5	−0.1 (5)	C12—C9—C10—N3	−178.6 (4)