(E)-4-Bromo-N-(2,4-dimethoxy­benzyl­idene)aniline

Khalaji, A.D.; Simpson, J.

doi:10.1107/S1600536809004905

organic compounds

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Volume 65| Part 3| March 2009| Page o553

doi:10.1107/S1600536809004905

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(E)-4-Bromo-N-(2,4-dimethoxybenzylidene)aniline

Aliakbar D. Khalaji ^a and Jim Simpson ^b ^*

^aDepartment of Chemistry, Faculty of Science, Golestan University, Gorgan, Iran, and ^bDepartment of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand
^*Correspondence e-mail: jsimpson@alkali.otago.ac.nz

(Received 9 February 2009; accepted 10 February 2009; online 21 February 2009)

The title Schiff base compound, C₁₅H₁₄BrNO₂, adopts an E configuration with respect to the C=N bond. The C and O atoms of the two methoxy substituents lie very close to the dimethoxyphenyl ring plane [maximum deviation = 0.17 (1) Å]. The dihedral angle between the two aromatic rings is 43.69 (16)°, while the plane through the central C—C=N—C system is inclined at 10.6 (6)° to the dimethoxyphenyl ring and 34.6 (3)° to the bromophenyl ring. In the crystal structure, each molecule is involved in the formation of two inversion-related dimers through weak C—H⋯N and C—H⋯O interactions, respectively. These contacts link the molecules into independent rows parallel to the b axis.

Related literature

For related structures, see: Khalaji et al. (2007 ); Khalaji & Harrison (2008 ); Khalaji & Simpson (2009 ). For reference structural data, see: Allen et al. (1987 ). For graph-set motifs, see: Bernstein et al. (1995 ).

Experimental

Crystal data

C₁₅H₁₄BrNO₂
M_r = 320.18
Monoclinic, P 2₁ /c
a = 4.1323 (6) Å
b = 10.7406 (14) Å
c = 29.911 (4) Å
β = 90.992 (8)°
V = 1327.4 (3) Å³
Z = 4
Mo Kα radiation
μ = 3.09 mm⁻¹
T = 89 K
0.25 × 0.10 × 0.02 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2006 ) T_min = 0.570, T_max = 0.940
13728 measured reflections
2390 independent reflections
1664 reflections with I > 2σ(I)
R_int = 0.106

Refinement

R[F² > 2σ(F²)] = 0.056
wR(F²) = 0.118
S = 1.21
2390 reflections
174 parameters
H-atom parameters constrained
Δρ_max = 0.83 e Å⁻³
Δρ_min = −0.82 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7A⋯N1ⁱ	0.98	2.74	3.667 (7)	159
C4—H4C⋯O2ⁱⁱ	0.98	2.54	3.398 (6)	145
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x+1, -y+2, -z+1.

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 and SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and TITAN2000 (Hunter & Simpson, 1999 ); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006 ); software used to prepare material for publication: SHELXL97, enCIFer (Allen et al., 2004 ), PLATON (Spek, 2009 ) and publCIF (Westrip, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809004905/ng2544sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809004905/ng2544Isup2.hkl

checkCIF report

Comment top

As a continuation of our work on the synthesis and structural characterization of Schiff-base compounds (Khalaji et al., 2007; Khalaji & Harrison, 2008; Khalaji & Simpson, 2009), we report here the structure of the title compound, C₁₅H₁₄BrNO₂, (I), Fig 1.

The compound adopts an E configuration with respect to the C1=N1 bond. The C4, O1 and C7 O2 methoxy substituents lie close to the plane of the C2···C9 ring (maximum deviation 0.17 (1) Å for C7. Bond lengths in the molecule are normal (Allen, et al., 1987) and similar to those found in related compounds (Khalaji et al., 2007; Khalaji & Harrison, 2008; Khalaji & Simpson 2009). The dihedral angle between the two aromatic rings is 43.69 (16) ° while the plane through the central C2—C2?N1—C10 system is inclined at 10.6 (6)° to the dimethoxyphenyl ring and 34.6 (3)° to the bromobenzene ring.

In the crystal structure, each molecule is involved in the formation of two inversion related dimers with R²₂(18) and R²₂(14) ring motifs (Bernstein et al. 1995) through weak C7—H7A···N1 and C4—H4···O2 interactions respectively, Table 1. These contacts link the molecules into independent rows parallel to the b axis, Fig. 2.

Related literature top

For related structures, see: Khalaji et al. (2007); Khalaji & Harrison (2008); Khalaji & Simpson (2009). For reference structural data, see: Allen et al. (1987). For graph-set motifs, see: Bernstein et al. (1995).

Experimental top

To a solution of 2,4-Dimethoxy benzaldehyde (332 mg, 0.2 mmol) in methanol (5 ml), cooled in an ice bath, a solution of 4-bromoaniline (344 mg, 0.2 mmol) in methanol (5 ml) was added slowly dropwise with constant stirring (1 h) at 298 k in the presence of molecular sieves. The mixture was filtered and the solution cooled to 273 K to give the compound in about 85% yield. Pale yellow crystals were grown from methanol.

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 (Bruker, 2006) and SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and TITAN (Hunter & Simpson, 1999); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004), PLATON (Spek, 2009) and publCIF (Westrip, 2009).

Figures top

	Fig. 1. The structure of (I) with displacement ellipsoids for the non-hydrogen atoms drawn at the 50% probability level.
	Fig. 2. Crystal packing of (I) viewed down the a axis with hydrogen bonds drawn as dashed lines. H atoms not involved in hydrogen bonding have been omitted.

(E)-4-Bromo-N-(2,4-dimethoxybenzylidene)aniline top

Crystal data top

C₁₅H₁₄BrNO₂	F(000) = 648
M_r = 320.18	D_x = 1.602 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2351 reflections
a = 4.1323 (6) Å	θ = 2.7–23.6°
b = 10.7406 (14) Å	µ = 3.09 mm⁻¹
c = 29.911 (4) Å	T = 89 K
β = 90.992 (8)°	Rectangular plate, pale yellow
V = 1327.4 (3) Å³	0.25 × 0.10 × 0.02 mm
Z = 4

Data collection top

Bruker APEXII CCD area-detector diffractometer	2390 independent reflections
Radiation source: fine-focus sealed tube	1664 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.106
ω scans	θ_max = 25.3°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2006)	h = −3→4
T_min = 0.570, T_max = 0.940	k = −12→12
13728 measured reflections	l = −35→35

Refinement top

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)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.118	H-atom parameters constrained
S = 1.21	w = 1/[σ²(F_o²) + (0.0212P)² + 3P] where P = (F_o² + 2F_c²)/3
2390 reflections	(Δ/σ)_max < 0.001
174 parameters	Δρ_max = 0.83 e Å⁻³
0 restraints	Δρ_min = −0.82 e Å⁻³

Crystal data top

C₁₅H₁₄BrNO₂	V = 1327.4 (3) Å³
M_r = 320.18	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 4.1323 (6) Å	µ = 3.09 mm⁻¹
b = 10.7406 (14) Å	T = 89 K
c = 29.911 (4) Å	0.25 × 0.10 × 0.02 mm
β = 90.992 (8)°

Data collection top

Bruker APEXII CCD area-detector diffractometer	2390 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2006)	1664 reflections with I > 2σ(I)
T_min = 0.570, T_max = 0.940	R_int = 0.106
13728 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.056	0 restraints
wR(F²) = 0.118	H-atom parameters constrained
S = 1.21	Δρ_max = 0.83 e Å⁻³
2390 reflections	Δρ_min = −0.82 e Å⁻³
174 parameters

Special details top

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 (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.8952 (10)	0.5770 (4)	0.37825 (15)	0.0157 (10)
C1	0.7282 (12)	0.6745 (5)	0.38778 (18)	0.0154 (12)
H1	0.6759	0.7321	0.3647	0.018*
C2	0.6171 (12)	0.6989 (5)	0.43302 (17)	0.0138 (12)
C3	0.4148 (12)	0.8016 (5)	0.44237 (18)	0.0133 (12)
O1	0.3071 (9)	0.8689 (3)	0.40592 (12)	0.0174 (9)
C4	0.1171 (13)	0.9771 (4)	0.41475 (18)	0.0159 (12)
H4A	−0.0826	0.9525	0.4296	0.024*
H4B	0.0632	1.0192	0.3865	0.024*
H4C	0.2406	1.0339	0.4342	0.024*
C5	0.3327 (12)	0.8293 (5)	0.48586 (18)	0.0155 (12)
H5	0.2003	0.8994	0.4919	0.019*
C6	0.4459 (12)	0.7535 (5)	0.52094 (17)	0.0138 (12)
O2	0.3510 (9)	0.7888 (3)	0.56290 (11)	0.0167 (9)
C7	0.4941 (14)	0.7232 (5)	0.59995 (18)	0.0222 (13)
H7A	0.4270	0.6357	0.5989	0.033*
H7B	0.4228	0.7607	0.6280	0.033*
H7C	0.7304	0.7283	0.5984	0.033*
C8	0.6428 (12)	0.6515 (5)	0.51264 (17)	0.0153 (12)
H8	0.7184	0.5999	0.5364	0.018*
C9	0.7263 (12)	0.6267 (5)	0.46874 (18)	0.0160 (12)
H9	0.8634	0.5578	0.4629	0.019*
C10	1.0177 (13)	0.5654 (6)	0.33449 (18)	0.0169 (13)
C11	1.1201 (12)	0.6657 (5)	0.30882 (18)	0.0181 (13)
H11	1.0997	0.7481	0.3200	0.022*
C12	1.2516 (13)	0.6466 (5)	0.26700 (18)	0.0179 (12)
H12	1.3267	0.7153	0.2501	0.022*
C13	1.2726 (12)	0.5278 (5)	0.25015 (18)	0.0164 (13)
Br1	1.44896 (13)	0.49899 (7)	0.192736 (17)	0.02466 (19)
C14	1.1702 (12)	0.4254 (5)	0.27488 (19)	0.0172 (12)
H14	1.1866	0.3432	0.2633	0.021*
C15	1.0447 (13)	0.4469 (6)	0.31650 (18)	0.0176 (13)
H15	0.9738	0.3779	0.3336	0.021*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.018 (2)	0.013 (3)	0.017 (2)	0.000 (2)	0.004 (2)	−0.0016 (19)
C1	0.018 (3)	0.011 (3)	0.017 (3)	−0.005 (2)	0.002 (2)	−0.003 (2)
C2	0.014 (3)	0.009 (3)	0.018 (3)	−0.001 (2)	0.003 (2)	−0.002 (2)
C3	0.008 (3)	0.013 (3)	0.019 (3)	0.000 (2)	0.001 (2)	−0.003 (2)
O1	0.020 (2)	0.016 (2)	0.016 (2)	0.0038 (17)	0.0036 (16)	−0.0012 (16)
C4	0.022 (3)	0.006 (3)	0.021 (3)	0.001 (2)	0.002 (2)	0.002 (2)
C5	0.015 (3)	0.008 (3)	0.024 (3)	−0.003 (2)	0.003 (2)	−0.003 (2)
C6	0.016 (3)	0.012 (3)	0.014 (3)	−0.006 (2)	0.002 (2)	−0.002 (2)
O2	0.023 (2)	0.015 (2)	0.012 (2)	−0.0021 (17)	0.0038 (16)	−0.0013 (16)
C7	0.036 (3)	0.015 (3)	0.015 (3)	−0.001 (3)	0.004 (3)	0.000 (2)
C8	0.017 (3)	0.016 (3)	0.013 (3)	−0.002 (2)	0.003 (2)	0.006 (2)
C9	0.014 (3)	0.012 (3)	0.022 (3)	−0.003 (2)	0.001 (2)	−0.003 (2)
C10	0.017 (3)	0.020 (3)	0.014 (3)	0.003 (2)	0.003 (2)	−0.005 (2)
C11	0.018 (3)	0.012 (3)	0.024 (3)	0.002 (2)	0.003 (2)	−0.002 (2)
C12	0.018 (3)	0.014 (3)	0.022 (3)	−0.003 (2)	0.007 (2)	0.002 (2)
C13	0.014 (3)	0.020 (4)	0.016 (3)	0.002 (2)	0.006 (2)	−0.005 (2)
Br1	0.0271 (3)	0.0313 (3)	0.0159 (3)	0.0036 (3)	0.0069 (2)	−0.0002 (3)
C14	0.020 (3)	0.009 (3)	0.022 (3)	0.002 (2)	0.005 (2)	−0.002 (2)
C15	0.022 (3)	0.016 (3)	0.014 (3)	−0.005 (2)	0.000 (3)	0.003 (2)

Geometric parameters (Å, º) top

N1—C1	1.288 (7)	C7—H7A	0.9800
N1—C10	1.417 (7)	C7—H7B	0.9800
C1—C2	1.460 (7)	C7—H7C	0.9800
C1—H1	0.9500	C8—C9	1.389 (7)
C2—C9	1.389 (7)	C8—H8	0.9500
C2—C3	1.415 (7)	C9—H9	0.9500
C3—O1	1.376 (6)	C10—C15	1.387 (8)
C3—C5	1.383 (7)	C10—C11	1.393 (8)
O1—C4	1.430 (6)	C11—C12	1.388 (7)
C4—H4A	0.9800	C11—H11	0.9500
C4—H4B	0.9800	C12—C13	1.375 (7)
C4—H4C	0.9800	C12—H12	0.9500
C5—C6	1.402 (7)	C13—C14	1.396 (7)
C5—H5	0.9500	C13—Br1	1.902 (5)
C6—O2	1.375 (6)	C14—C15	1.376 (8)
C6—C8	1.390 (7)	C14—H14	0.9500
O2—C7	1.432 (6)	C15—H15	0.9500

C1—N1—C10	118.5 (5)	O2—C7—H7C	109.5
N1—C1—C2	122.0 (5)	H7A—C7—H7C	109.5
N1—C1—H1	119.0	H7B—C7—H7C	109.5
C2—C1—H1	119.0	C6—C8—C9	118.4 (5)
C9—C2—C3	117.9 (5)	C6—C8—H8	120.8
C9—C2—C1	120.6 (5)	C9—C8—H8	120.8
C3—C2—C1	121.3 (5)	C2—C9—C8	122.5 (5)
O1—C3—C5	123.4 (5)	C2—C9—H9	118.7
O1—C3—C2	115.9 (4)	C8—C9—H9	118.7
C5—C3—C2	120.6 (5)	C15—C10—C11	117.9 (5)
C3—O1—C4	116.9 (4)	C15—C10—N1	118.1 (5)
O1—C4—H4A	109.5	C11—C10—N1	123.9 (5)
O1—C4—H4B	109.5	C12—C11—C10	120.6 (5)
H4A—C4—H4B	109.5	C12—C11—H11	119.7
O1—C4—H4C	109.5	C10—C11—H11	119.7
H4A—C4—H4C	109.5	C13—C12—C11	119.7 (5)
H4B—C4—H4C	109.5	C13—C12—H12	120.1
C3—C5—C6	119.7 (5)	C11—C12—H12	120.1
C3—C5—H5	120.2	C12—C13—C14	121.0 (5)
C6—C5—H5	120.2	C12—C13—Br1	120.6 (4)
O2—C6—C8	123.9 (5)	C14—C13—Br1	118.3 (4)
O2—C6—C5	115.2 (5)	C15—C14—C13	118.0 (5)
C8—C6—C5	120.9 (5)	C15—C14—H14	121.0
C6—O2—C7	116.8 (4)	C13—C14—H14	121.0
O2—C7—H7A	109.5	C14—C15—C10	122.6 (5)
O2—C7—H7B	109.5	C14—C15—H15	118.7
H7A—C7—H7B	109.5	C10—C15—H15	118.7

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···N1ⁱ	0.98	2.74	3.667 (7)	159
C4—H4C···O2ⁱⁱ	0.98	2.54	3.398 (6)	145

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+2, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₅H₁₄BrNO₂
M_r	320.18
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	89
a, b, c (Å)	4.1323 (6), 10.7406 (14), 29.911 (4)
β (°)	90.992 (8)
V (Å³)	1327.4 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	3.09
Crystal size (mm)	0.25 × 0.10 × 0.02

Data collection
Diffractometer	Bruker APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2006)
T_min, T_max	0.570, 0.940
No. of measured, independent and observed [I > 2σ(I)] reflections	13728, 2390, 1664
R_int	0.106
(sin θ/λ)_max (Å⁻¹)	0.601

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.056, 0.118, 1.21
No. of reflections	2390
No. of parameters	174
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.83, −0.82

Computer programs: , APEX2 (Bruker, 2006) and SAINT (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and TITAN (Hunter & Simpson, 1999), SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006), SHELXL97 (Sheldrick, 2008), enCIFer (Allen et al., 2004), PLATON (Spek, 2009) and publCIF (Westrip, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···N1ⁱ	0.98	2.74	3.667 (7)	158.5
C4—H4C···O2ⁱⁱ	0.98	2.54	3.398 (6)	145.4

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1, −y+2, −z+1.

Acknowledgements

We thank the University of Otago for purchase of the diffractometer.

References

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