3,4-Dimeth­oxy-N-(4-nitro­benzyl­idene)­aniline

Akkurt, M.; Jarrahpour, A.; Aye, M.; Gençaslan, M.; Büyükgüngör, O.

doi:10.1107/S1600536808032042

3,4-Dimethoxy-N-(4-nitrobenzylidene)aniline

M. Akkurt, A. Jarrahpour, M. Aye, M. Gençaslan and O. Büyükgüngör

In the title molecule, C₁₅H₁₄N₂O₄, the dihedral angle between the two benzene rings is 29.52 (8)°. The nitro and two methoxy substituents are almost coplanar with their respective benzene rings. The crystal structure is stabilized by intermolecular C—H

O interactions.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536808032042/tk2312sup1.cif Contains datablocks global, I
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536808032042/tk2312Isup2.hkl Contains datablock I

CCDC reference: 709331

checkCIF report

Key indicators

Single-crystal X-ray study
T = 296 K
Mean (C-C) = 0.002 Å
R factor = 0.040
wR factor = 0.120
Data-to-parameter ratio = 15.1

checkCIF/PLATON results

No syntax errors found



Alert level C
            Value of measurement temperature given =   296.000
            Value of melting point given =     0.000
SHFSU01_ALERT_2_C  Test not performed. _refine_ls_shift/su_max and
            _refine_ls_shift/esd_max not present.
            Absolute value of the parameter shift to su ratio given   0.001
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

Comment top

Schiff bases belong to a widely used group of organic intermediates which are important for production of certain chemicals, such as pharmaceuticals and rubber additives (Macho et al., 2004), and as amino protective groups in organic synthesis (Bey & Vevert, 1977; Lucas et al., 1960; Fleet & Fleming, 1969; Bezas & Zervas, 1961). As we are interested in Schiff bases, we report here the crystal structure of the title compound, (I).

In (I), Fig. 1, the dihedral angle between the two benzene rings (C1–C6) and (C10–C15) is 29.52 (8)° and the C1—N1—C9—C10 torsion angle is 176.12 (15)°. The nitro and two methoxy substituents are coplanar with their respective benzene rings.

The crystal structure of (I) is stabilized by intermolecular C—H···O interactions, Fig. 2 and Table 1.

Related literature top

For general background, see: Bey & Vevert (1977); Bezas & Zervas (1961); Fleet & Fleming (1969); Lucas et al. (1960); Macho et al. (2004). For a related structure, see: Akkurt et al. (2005).

Experimental top

A mixture of 3,4-dimethoxyaniline (3 mmol) and 4-nitrobenzaldehyde (3 mmol) was refluxed in EtOH for 4 h. After cooling the solution, the formed precipitate was filtered off and washed with ethanol to give pure Schiff base as an orange solid in an 89% yield; m. pt. = 429–431 K. IR (KBr, cm^-1): 1600.3 (C?N). ¹H NMR (CDCl₃) δ 3.92, 3.94 (2 x OCH₃, s, 6H), 6.92–8.66 (ArH, m, 7H), 8.90 (HC?N, s, 1H). ¹³C NMR (CDCl₃) δ 55.97, 56.12 (2 OCH₃), 105.63–149.50 (C?C aromatic carbons), 155.03 (C?N).

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. View of (I) showing with the atom-numbering scheme and 50% probability displacement ellipsoids
	Fig. 2. View down the b axis of the packing and C—H···O contacts in the unit cell of (I). H atoms not involved in C—H···O contacts (dashed lines) have been omitted for clarity.

3,4-Dimethoxy-N-(4-nitrobenzylidene)aniline top

Crystal data top

C₁₅H₁₄N₂O₄	F(000) = 600
M_r = 286.28	D_x = 1.370 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 11667 reflections
a = 7.9536 (4) Å	θ = 1.9–27.3°
b = 8.2258 (3) Å	µ = 0.10 mm⁻¹
c = 21.3418 (10) Å	T = 296 K
β = 96.125 (4)°	Prism, brown
V = 1388.31 (11) Å³	0.25 × 0.21 × 0.18 mm
Z = 4

Data collection top

Stoe IPDS II diffractometer	2880 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	1797 reflections with I > 2σ(I)
Plane graphite monochromator	R_int = 0.038
Detector resolution: 6.67 pixels mm^-1	θ_max = 26.5°, θ_min = 1.9°
ω scans	h = −9→9
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −10→10
T_min = 0.975, T_max = 0.982	l = −26→26
14598 measured reflections

Refinement top

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)] = 0.040	H-atom parameters constrained
wR(F²) = 0.120	w = 1/[σ²(F_o²) + (0.0824P)²] where P = (F_o² + 2F_c²)/3
S = 0.83	(Δ/σ)_max < 0.001
2880 reflections	Δρ_max = 0.13 e Å⁻³
191 parameters	Δρ_min = −0.12 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=KFc[1+0.001Fc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0071 (16)

Crystal data top

C₁₅H₁₄N₂O₄	V = 1388.31 (11) Å³
M_r = 286.28	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 7.9536 (4) Å	µ = 0.10 mm⁻¹
b = 8.2258 (3) Å	T = 296 K
c = 21.3418 (10) Å	0.25 × 0.21 × 0.18 mm
β = 96.125 (4)°

Data collection top

Stoe IPDS II diffractometer	2880 independent reflections
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	1797 reflections with I > 2σ(I)
T_min = 0.975, T_max = 0.982	R_int = 0.038
14598 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.040	0 restraints
wR(F²) = 0.120	H-atom parameters constrained
S = 0.83	Δρ_max = 0.13 e Å⁻³
2880 reflections	Δρ_min = −0.12 e Å⁻³
191 parameters

Special details top

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 on F² for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > σ(F²) is used only for calculating -R-factor-obs 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 (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.34730 (16)	−0.17529 (15)	0.28084 (6)	0.0633 (4)
O2	0.14131 (16)	0.04285 (15)	0.23416 (6)	0.0624 (4)
O3	0.1545 (2)	1.09341 (17)	0.58860 (7)	0.0859 (6)
O4	0.2133 (2)	0.96182 (16)	0.67456 (6)	0.0775 (6)
N1	0.2395 (2)	0.38177 (18)	0.41916 (7)	0.0580 (5)
N2	0.1851 (2)	0.96644 (18)	0.61754 (7)	0.0578 (5)
C1	0.2679 (2)	0.2324 (2)	0.38839 (8)	0.0524 (6)
C2	0.3732 (2)	0.1113 (2)	0.41434 (8)	0.0581 (6)
C3	0.4020 (2)	−0.0275 (2)	0.37992 (9)	0.0575 (6)
C4	0.3240 (2)	−0.0470 (2)	0.31966 (8)	0.0509 (5)
C5	0.2137 (2)	0.0741 (2)	0.29350 (8)	0.0503 (6)
C6	0.1891 (2)	0.2128 (2)	0.32730 (8)	0.0536 (6)
C7	0.4578 (3)	−0.3022 (3)	0.30482 (11)	0.0780 (8)
C8	0.0173 (3)	0.1542 (2)	0.20751 (9)	0.0637 (7)
C9	0.2415 (2)	0.3850 (2)	0.47827 (9)	0.0571 (6)
C10	0.2237 (2)	0.5361 (2)	0.51351 (8)	0.0520 (6)
C11	0.1908 (2)	0.6842 (2)	0.48291 (8)	0.0574 (6)
C12	0.1756 (2)	0.8243 (2)	0.51682 (8)	0.0566 (6)
C13	0.1945 (2)	0.8156 (2)	0.58166 (8)	0.0492 (5)
C14	0.2255 (2)	0.6721 (2)	0.61381 (8)	0.0560 (6)
C15	0.2377 (2)	0.5328 (2)	0.57890 (8)	0.0588 (6)
H2	0.42540	0.12260	0.45520	0.0700*
H3	0.47450	−0.10770	0.39770	0.0690*
H6	0.11900	0.29450	0.30920	0.0640*
H7A	0.46300	−0.38430	0.27310	0.1170*
H7B	0.41610	−0.34920	0.34130	0.1170*
H7C	0.56890	−0.25870	0.31620	0.1170*
H8A	−0.02420	0.11930	0.16580	0.0960*
H8B	0.06680	0.26030	0.20550	0.0960*
H8C	−0.07470	0.15840	0.23320	0.0960*
H9	0.25480	0.28770	0.50050	0.0690*
H11	0.17910	0.68810	0.43910	0.0690*
H12	0.15290	0.92300	0.49640	0.0680*
H14	0.23770	0.66920	0.65760	0.0670*
H15	0.25570	0.43380	0.59960	0.0710*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0634 (8)	0.0591 (7)	0.0660 (8)	0.0120 (6)	0.0008 (6)	−0.0126 (6)
O2	0.0720 (8)	0.0637 (8)	0.0490 (7)	0.0131 (6)	−0.0053 (6)	−0.0096 (6)
O3	0.1359 (14)	0.0530 (8)	0.0664 (9)	0.0118 (8)	−0.0004 (9)	0.0023 (7)
O4	0.1171 (12)	0.0690 (9)	0.0466 (8)	−0.0019 (8)	0.0094 (8)	−0.0067 (7)
N1	0.0677 (10)	0.0568 (9)	0.0489 (9)	−0.0007 (7)	0.0037 (7)	−0.0073 (7)
N2	0.0698 (10)	0.0533 (9)	0.0501 (9)	−0.0024 (7)	0.0059 (7)	−0.0002 (7)
C1	0.0570 (10)	0.0523 (10)	0.0483 (9)	−0.0023 (8)	0.0075 (8)	−0.0046 (8)
C2	0.0580 (10)	0.0687 (12)	0.0467 (10)	0.0004 (9)	0.0009 (8)	−0.0034 (9)
C3	0.0532 (10)	0.0606 (11)	0.0581 (11)	0.0081 (8)	0.0033 (8)	0.0016 (9)
C4	0.0490 (9)	0.0505 (9)	0.0538 (10)	0.0010 (8)	0.0081 (8)	−0.0052 (8)
C5	0.0511 (10)	0.0546 (10)	0.0451 (9)	−0.0018 (8)	0.0045 (7)	−0.0038 (8)
C6	0.0606 (11)	0.0525 (10)	0.0475 (9)	0.0049 (8)	0.0055 (8)	−0.0008 (8)
C7	0.0742 (14)	0.0677 (13)	0.0899 (16)	0.0252 (11)	−0.0007 (12)	−0.0115 (11)
C8	0.0767 (13)	0.0642 (12)	0.0482 (10)	0.0096 (9)	−0.0024 (9)	0.0049 (9)
C9	0.0669 (11)	0.0538 (10)	0.0508 (10)	−0.0017 (9)	0.0076 (8)	−0.0026 (8)
C10	0.0577 (10)	0.0530 (10)	0.0455 (9)	−0.0036 (8)	0.0063 (8)	−0.0023 (8)
C11	0.0716 (12)	0.0605 (11)	0.0393 (9)	−0.0030 (9)	0.0021 (8)	0.0017 (8)
C12	0.0707 (12)	0.0508 (10)	0.0472 (10)	−0.0016 (8)	0.0019 (8)	0.0042 (8)
C13	0.0545 (10)	0.0501 (9)	0.0430 (9)	−0.0058 (7)	0.0053 (7)	−0.0017 (7)
C14	0.0718 (12)	0.0566 (10)	0.0399 (9)	−0.0004 (9)	0.0073 (8)	0.0030 (8)
C15	0.0786 (13)	0.0503 (10)	0.0478 (10)	0.0033 (9)	0.0081 (9)	0.0049 (8)

Geometric parameters (Å, º) top

O1—C4	1.366 (2)	C11—C12	1.373 (2)
O1—C7	1.424 (3)	C12—C13	1.378 (2)
O2—C5	1.359 (2)	C13—C14	1.374 (2)
O2—C8	1.420 (2)	C14—C15	1.376 (2)
O3—N2	1.225 (2)	C2—H2	0.9300
O4—N2	1.214 (2)	C3—H3	0.9300
N1—C1	1.423 (2)	C6—H6	0.9300
N1—C9	1.260 (2)	C7—H7A	0.9600
N2—C13	1.464 (2)	C7—H7B	0.9600
C1—C2	1.379 (2)	C7—H7C	0.9600
C1—C6	1.394 (2)	C8—H8A	0.9600
C2—C3	1.390 (2)	C8—H8B	0.9600
C3—C4	1.376 (3)	C8—H8C	0.9600
C4—C5	1.403 (2)	C9—H9	0.9300
C5—C6	1.375 (2)	C11—H11	0.9300
C9—C10	1.467 (2)	C12—H12	0.9300
C10—C11	1.394 (2)	C14—H14	0.9300
C10—C15	1.388 (2)	C15—H15	0.9300

O1···O2	2.5589 (18)	H2···H9	2.2100
O1···C8ⁱ	3.255 (3)	H3···C7	2.5400
O2···C14ⁱⁱ	3.246 (2)	H3···H7B	2.3400
O2···O1	2.5589 (18)	H3···H7C	2.3300
O3···C12ⁱⁱⁱ	3.340 (2)	H6···C8	2.5100
O4···C8^iv	3.405 (3)	H6···H8B	2.2300
O1···H8Cⁱ	2.5500	H6···H8C	2.3900
O1···H14ⁱⁱ	2.6800	H7A···C4^xiii	3.0500
O2···H14ⁱⁱ	2.5600	H7A···C5^xiii	3.0900
O3···H12	2.4100	H7A···O4ⁱⁱ	2.8100
O3···H15^v	2.9200	H7B···C3	2.7800
O3···H12ⁱⁱⁱ	2.8900	H7B···H3	2.3400
O3···H9^v	2.6500	H7C···C3	2.7600
O4···H14	2.4400	H7C···H3	2.3300
O4···H8C^iv	2.5600	H7C···H15^xii	2.5900
O4···H7A^vi	2.8100	H8A···H11ⁱ	2.5000
O4···H8B^vii	2.6800	H8B···C6	2.7000
N2···C3^viii	3.317 (2)	H8B···H6	2.2300
N1···H11	2.6100	H8B···O4^xiv	2.6800
C2···C13^viii	3.483 (2)	H8C···C6	2.7800
C3···N2^viii	3.317 (2)	H8C···H6	2.3900
C8···O4^iv	3.405 (3)	H8C···O1^ix	2.5500
C8···O1^ix	3.255 (3)	H8C···C7^ix	3.0900
C10···C10^iv	3.593 (2)	H8C···O4^iv	2.5600
C12···O3ⁱⁱⁱ	3.340 (2)	H9···O3^x	2.6500
C13···C2^viii	3.483 (2)	H9···C2	2.6000
C14···O2^vi	3.246 (2)	H9···H2	2.2100
C2···H9	2.6000	H9···H15	2.4300
C2···H12^x	3.0300	H11···N1	2.6100
C3···H7C	2.7600	H11···H8A^ix	2.5000
C3···H7B	2.7800	H12···O3	2.4100
C4···H7A^xi	3.0500	H12···C2^v	3.0300
C5···H7A^xi	3.0900	H12···O3ⁱⁱⁱ	2.8900
C6···H8C	2.7800	H14···O4	2.4400
C6···H8B	2.7000	H14···O1^vi	2.6800
C7···H15^xii	3.0900	H14···O2^vi	2.5600
C7···H3	2.5400	H15···O3^x	2.9200
C7···H8Cⁱ	3.0900	H15···H9	2.4300
C8···H6	2.5100	H15···C7^xii	3.0900
C9···H2	2.6800	H15···H7C^xii	2.5900
H2···C9	2.6800

C4—O1—C7	117.82 (15)	C1—C2—H2	120.00
C5—O2—C8	117.30 (13)	C3—C2—H2	120.00
C1—N1—C9	119.65 (15)	C2—C3—H3	120.00
O3—N2—O4	122.53 (15)	C4—C3—H3	120.00
O3—N2—C13	118.52 (15)	C1—C6—H6	120.00
O4—N2—C13	118.90 (14)	C5—C6—H6	120.00
N1—C1—C2	123.93 (15)	O1—C7—H7A	109.00
N1—C1—C6	116.99 (15)	O1—C7—H7B	109.00
C2—C1—C6	119.02 (15)	O1—C7—H7C	109.00
C1—C2—C3	120.56 (16)	H7A—C7—H7B	109.00
C2—C3—C4	120.42 (15)	H7A—C7—H7C	109.00
O1—C4—C3	125.44 (15)	H7B—C7—H7C	109.00
O1—C4—C5	115.25 (15)	O2—C8—H8A	110.00
C3—C4—C5	119.30 (15)	O2—C8—H8B	109.00
O2—C5—C4	114.92 (14)	O2—C8—H8C	109.00
O2—C5—C6	125.18 (15)	H8A—C8—H8B	109.00
C4—C5—C6	119.88 (15)	H8A—C8—H8C	109.00
C1—C6—C5	120.77 (15)	H8B—C8—H8C	109.00
N1—C9—C10	122.64 (16)	N1—C9—H9	119.00
C9—C10—C11	121.59 (16)	C10—C9—H9	119.00
C9—C10—C15	119.79 (15)	C10—C11—H11	120.00
C11—C10—C15	118.62 (15)	C12—C11—H11	120.00
C10—C11—C12	120.62 (16)	C11—C12—H12	121.00
C11—C12—C13	118.65 (15)	C13—C12—H12	121.00
N2—C13—C12	118.37 (15)	C13—C14—H14	121.00
N2—C13—C14	118.90 (15)	C15—C14—H14	121.00
C12—C13—C14	122.72 (16)	C10—C15—H15	119.00
C13—C14—C15	117.66 (16)	C14—C15—H15	119.00
C10—C15—C14	121.69 (15)

C7—O1—C4—C5	−179.92 (16)	C3—C4—C5—O2	−179.20 (15)
C7—O1—C4—C3	1.8 (2)	O1—C4—C5—C6	−176.25 (15)
C8—O2—C5—C6	−6.9 (2)	O1—C4—C5—O2	2.4 (2)
C8—O2—C5—C4	174.56 (15)	C3—C4—C5—C6	2.2 (2)
C1—N1—C9—C10	176.12 (15)	C4—C5—C6—C1	−2.3 (2)
C9—N1—C1—C2	−33.0 (3)	O2—C5—C6—C1	179.20 (15)
C9—N1—C1—C6	149.95 (17)	N1—C9—C10—C11	4.9 (3)
O3—N2—C13—C12	2.7 (2)	N1—C9—C10—C15	−175.92 (16)
O4—N2—C13—C12	−174.90 (16)	C9—C10—C11—C12	−179.62 (15)
O3—N2—C13—C14	−178.74 (16)	C15—C10—C11—C12	1.2 (2)
O4—N2—C13—C14	3.6 (2)	C9—C10—C15—C14	178.57 (15)
N1—C1—C6—C5	178.12 (15)	C11—C10—C15—C14	−2.2 (2)
C2—C1—C6—C5	0.9 (2)	C10—C11—C12—C13	0.4 (2)
N1—C1—C2—C3	−176.33 (16)	C11—C12—C13—N2	177.51 (15)
C6—C1—C2—C3	0.7 (2)	C11—C12—C13—C14	−1.0 (2)
C1—C2—C3—C4	−0.8 (3)	N2—C13—C14—C15	−178.48 (15)
C2—C3—C4—O1	177.65 (15)	C12—C13—C14—C15	0.0 (2)
C2—C3—C4—C5	−0.6 (2)	C13—C14—C15—C10	1.6 (2)

Symmetry codes: (i) −x, y−1/2, −z+1/2; (ii) x, −y+1/2, z−1/2; (iii) −x, −y+2, −z+1; (iv) −x, −y+1, −z+1; (v) x, y+1, z; (vi) x, −y+1/2, z+1/2; (vii) x, −y+3/2, z+1/2; (viii) −x+1, −y+1, −z+1; (ix) −x, y+1/2, −z+1/2; (x) x, y−1, z; (xi) −x+1, y+1/2, −z+1/2; (xii) −x+1, −y, −z+1; (xiii) −x+1, y−1/2, −z+1/2; (xiv) x, −y+3/2, z−1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8C···O1^ix	0.96	2.55	3.255 (3)	130
C8—H8C···O4^iv	0.96	2.56	3.405 (3)	147
C14—H14···O2^vi	0.93	2.56	3.246 (2)	131

Symmetry codes: (iv) −x, −y+1, −z+1; (vi) x, −y+1/2, z+1/2; (ix) −x, y+1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₁₅H₁₄N₂O₄
M_r	286.28
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	7.9536 (4), 8.2258 (3), 21.3418 (10)
β (°)	96.125 (4)
V (Å³)	1388.31 (11)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.25 × 0.21 × 0.18

Data collection
Diffractometer	Stoe IPDS II diffractometer
Absorption correction	Integration (X-RED32; Stoe & Cie, 2002)
T_min, T_max	0.975, 0.982
No. of measured, independent and observed [I > 2σ(I)] reflections	14598, 2880, 1797
R_int	0.038
(sin θ/λ)_max (Å⁻¹)	0.628

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.120, 0.83
No. of reflections	2880
No. of parameters	191
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.13, −0.12

Computer programs: X-AREA (Stoe & Cie, 2002), X-RED32 (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).