N,N′-Bis(4-bromo­phen­yl)-N,N′-di­methyl­urea

Pocinho, A.; Mallet-Ladeira, S.; Hureau, C.; Gras, E.

doi:10.1107/S2414314618001864

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 3| Part 2| February 2018| x180186

https://doi.org/10.1107/S2414314618001864

Open

access

N,N′-Bis(4-bromophenyl)-N,N′-dimethylurea

Alexandre Pocinho,^a Sonia Mallet-Ladeira,^a Christelle Hureau ^a and Emmanuel Gras ^a ^*

^aLaboratoire de Chimie de Coordination, C.N.R.S., 205 route de Narbonne, BP 44099, 31077 Toulouse Cedex 4, France
^*Correspondence e-mail: emmanuel.gras@lcc-toulouse.fr

Edited by J. Simpson, University of Otago, New Zealand (Received 18 January 2018; accepted 30 January 2018; online 2 February 2018)

The structure of the title compound, C₁₅H₁₄Br₂N₂O, at 180 K has monoclinic (P2₁/n) symmetry. It was obtained unexpectedly from the decomposition of the parent 4-bromo-N-tert-butoxycarbonyl-N-methyl-aniline. It exhibits an `endo' conformation with angles between the two aromatic rings slightly lower than the average values found for similar compounds on the Cambridge Structural Database. In the crystal, C—H⋯O hydrogen bonds and short Br⋯Br halogen bonds [3.444 (1) Å] are observed.

Keywords: crystal structure; urea; folding; instability on storage.

CCDC reference: 1820748

Structure description

In the title compound, an `endo' conformation is observed with the two aryl rings facing each other (Fig. 1). This structural feature has been observed previously and shown to be specific to N,N,N′,N′-tetrasubstituted-N,N′-diaryl urea derivatives (Clayden et al., 2010 ; Hisamatsu et al., 2011a ,b ; Hisamatsu et al., 2012 ; Snape et al., 2012 ). The planes of the two benzene rings are twisted by an angle of 29.51 (11)°, which compares moderately well with the average value found for similar structures in the CSD (Version 5.38, updated November 2016; Groom et al., 2016 ). 44 structures were found, minimum angle 15.14°, maximum angle 81.25° with an average value of 33.59°. The C4—N1⋯N2—C10 torsion angle is 47.76° while the corresponding values obtained from the database for the 44 hits lie between 22.56 and 122.96° with an average value of 56.45°.

Figure 1
The molecular structure of the title compound showing the atom numbering with displacement ellipsoids drawn at the 50% probability level.

In the crystal, O2 acts as a bifurcated acceptor, forming C6—H6⋯O2 and C11—H11⋯O2 hydrogen bonds, Table 1. These combine with Br1⋯Br2ⁱⁱⁱ short contacts [3.444 (1) Å; symmetry code: (iii) $[{3\over 2}]$ − x, $[{1\over 2}]$ + y, $[{1\over 2}]$ − z] to generate a three-dimensional network, Fig. 2.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6⋯O2ⁱ	0.95	2.59	3.526 (3)	170
C11—H11⋯O2ⁱⁱ	0.95	2.42	3.365 (3)	178
Symmetry codes: (i) x+1, y, z; (ii) -x, -y+1, -z+1.

Figure 2
A view of the extended structure of the title compound with hydrogen bonds drawn as dashed lines. Hydrogen atoms not involved in hydrogen bonding have been omitted.

Synthesis and crystallization

Crystals of the title compound were obtained from 1 g of the oil of neat tert-butyl (4-bromophenyl)methylcarbamate (previously purified by column chromatography), upon standing in air for two months. This indicates the unprecedented instability of this Boc-protected aniline (Fig. 3). The crystals were washed with 10 mL of cyclohexane, providing 50 mg of crystals of the title compound.

Figure 3
Chemical scheme showing the formation of the title compound from the corresponding Boc-protected aniline

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₅H₁₄Br₂N₂O
M_r	398.08
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	180
a, b, c (Å)	9.1622 (2), 12.8617 (4), 13.1863 (3)
β (°)	99.307 (3)
V (Å³)	1533.44 (7)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	5.28
Crystal size (mm)	0.4 × 0.36 × 0.28

Data collection
Diffractometer	Agilent Xcalibur, Eos, Gemini ultra
Absorption correction	Multi-scan (CrysAlis PRO; Agilent, 2014 )
T_min, T_max	0.319, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	31347, 3484, 2771
R_int	0.043
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.077, 1.05
No. of reflections	3484
No. of parameters	182
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.69, −0.77
Computer programs: CrysAlis PRO (Agilent, 2014), SIR92 (Altomare et al., 1994 ), SHELXL2014 (Sheldrick, 2015 ) and ORTEP-3 for Windows and WinGX (Farrugia, 2012 ).

Structural data

CCDC reference: 1820748

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314618001864/sj4156sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314618001864/sj4156Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314618001864/sj4156Isup3.cml

checkCIF report

Computing details top

Data collection: CrysAlis PRO (Agilent, 2014); cell refinement: CrysAlis PRO (Agilent, 2014); data reduction: CrysAlis PRO (Agilent, 2014); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012).

N,N'-Bis(4-bromophenyl)-N,N'-dimethylurea top

Crystal data top

C₁₅H₁₄Br₂N₂O	F(000) = 784
M_r = 398.08	D_x = 1.724 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 7189 reflections
a = 9.1622 (2) Å	θ = 3.3–28.2°
b = 12.8617 (4) Å	µ = 5.28 mm⁻¹
c = 13.1863 (3) Å	T = 180 K
β = 99.307 (3)°	Block, colourless
V = 1533.44 (7) Å³	0.4 × 0.36 × 0.28 mm
Z = 4

Data collection top

Agilent Xcalibur, Eos, Gemini ultra diffractometer	3484 independent reflections
Radiation source: Enhance (Mo) X-ray Source	2771 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.043
ω scans	θ_max = 27.5°, θ_min = 2.9°
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2014)	h = −11→11
T_min = 0.319, T_max = 1.000	k = −16→16
31347 measured reflections	l = −17→17

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.033	H-atom parameters constrained
wR(F²) = 0.077	w = 1/[σ²(F_o²) + (0.0356P)² + 1.0497P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.001
3484 reflections	Δρ_max = 0.69 e Å⁻³
182 parameters	Δρ_min = −0.77 e Å⁻³

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.5095 (3)	0.1833 (2)	0.44957 (19)	0.0284 (6)
C2	0.3728 (3)	0.1366 (2)	0.4417 (2)	0.0317 (6)
H2	0.3595	0.0667	0.4187	0.038*
C3	0.2553 (3)	0.1923 (2)	0.46768 (19)	0.0295 (6)
H3	0.1609	0.1605	0.4634	0.035*
C4	0.2753 (3)	0.2948 (2)	0.49998 (17)	0.0244 (5)
C5	0.4145 (3)	0.3395 (2)	0.50894 (19)	0.0268 (5)
H5	0.4287	0.409	0.5328	0.032*
C6	0.5329 (3)	0.2842 (2)	0.4835 (2)	0.0295 (6)
H6	0.6281	0.315	0.4894	0.035*
C7	0.1558 (3)	0.3762 (3)	0.6339 (2)	0.0401 (7)
H7A	0.0892	0.4344	0.641	0.06*
H7B	0.2565	0.3944	0.6661	0.06*
H7C	0.123	0.3145	0.6676	0.06*
C8	0.0184 (3)	0.3570 (2)	0.4626 (2)	0.0278 (6)
C9	−0.1240 (3)	0.3325 (3)	0.2923 (2)	0.0450 (8)
H9A	−0.1536	0.2599	0.299	0.068*
H9B	−0.1144	0.3467	0.2207	0.068*
H9C	−0.199	0.3785	0.3132	0.068*
C10	0.1394 (3)	0.3795 (2)	0.30935 (18)	0.0240 (5)
C11	0.2114 (3)	0.4727 (2)	0.33029 (19)	0.0269 (5)
H11	0.1798	0.5196	0.378	0.032*
C12	0.3302 (3)	0.4984 (2)	0.2819 (2)	0.0286 (6)
H12	0.3814	0.5622	0.2971	0.034*
C13	0.3732 (3)	0.4303 (2)	0.21162 (19)	0.0268 (6)
C14	0.3013 (3)	0.3378 (2)	0.1880 (2)	0.0329 (6)
H14	0.3312	0.292	0.1387	0.039*
C15	0.1840 (3)	0.3128 (2)	0.2376 (2)	0.0327 (6)
H15	0.1333	0.2489	0.2223	0.039*
N1	0.1540 (2)	0.35407 (18)	0.52462 (15)	0.0290 (5)
N2	0.0177 (2)	0.35073 (18)	0.35812 (16)	0.0304 (5)
O2	−0.0968 (2)	0.36539 (16)	0.49821 (15)	0.0374 (5)
Br1	0.66952 (4)	0.10678 (3)	0.41141 (2)	0.04620 (11)
Br2	0.53294 (3)	0.46621 (3)	0.14348 (2)	0.04781 (11)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0319 (14)	0.0326 (14)	0.0221 (12)	0.0102 (12)	0.0087 (11)	0.0044 (11)
C2	0.0430 (17)	0.0269 (14)	0.0253 (13)	0.0013 (12)	0.0054 (12)	0.0021 (11)
C3	0.0289 (14)	0.0340 (15)	0.0257 (13)	−0.0050 (11)	0.0047 (11)	0.0048 (11)
C4	0.0254 (13)	0.0315 (14)	0.0164 (11)	0.0029 (11)	0.0040 (9)	0.0026 (10)
C5	0.0257 (13)	0.0263 (14)	0.0268 (13)	0.0008 (10)	−0.0006 (10)	−0.0012 (10)
C6	0.0222 (13)	0.0363 (15)	0.0295 (13)	0.0011 (11)	0.0024 (10)	0.0073 (11)
C7	0.0395 (17)	0.059 (2)	0.0213 (13)	0.0147 (14)	0.0037 (12)	−0.0055 (13)
C8	0.0238 (13)	0.0339 (14)	0.0262 (13)	−0.0004 (11)	0.0052 (11)	0.0005 (11)
C9	0.0289 (15)	0.070 (2)	0.0338 (16)	−0.0149 (15)	−0.0035 (12)	−0.0055 (15)
C10	0.0202 (12)	0.0323 (14)	0.0187 (11)	0.0006 (10)	0.0004 (9)	0.0021 (10)
C11	0.0300 (14)	0.0262 (13)	0.0239 (12)	0.0036 (11)	0.0018 (10)	0.0009 (10)
C12	0.0278 (14)	0.0255 (13)	0.0308 (14)	−0.0041 (11)	0.0001 (11)	0.0051 (11)
C13	0.0228 (13)	0.0362 (14)	0.0212 (12)	0.0002 (11)	0.0030 (10)	0.0109 (11)
C14	0.0390 (16)	0.0375 (16)	0.0241 (13)	0.0018 (12)	0.0106 (12)	−0.0023 (11)
C15	0.0404 (16)	0.0317 (15)	0.0268 (13)	−0.0103 (12)	0.0082 (12)	−0.0057 (11)
N1	0.0246 (11)	0.0430 (13)	0.0192 (10)	0.0068 (10)	0.0034 (9)	−0.0026 (9)
N2	0.0193 (11)	0.0485 (14)	0.0229 (11)	−0.0060 (10)	0.0016 (9)	0.0007 (10)
O2	0.0232 (10)	0.0557 (13)	0.0353 (10)	0.0000 (9)	0.0110 (8)	−0.0047 (9)
Br1	0.0511 (2)	0.0519 (2)	0.04037 (18)	0.02521 (15)	0.02171 (14)	0.00926 (14)
Br2	0.03153 (17)	0.0754 (3)	0.03916 (18)	−0.00702 (15)	0.01386 (13)	0.01359 (15)

Geometric parameters (Å, º) top

C1—C2	1.377 (4)	C8—N2	1.379 (3)
C1—C6	1.377 (4)	C9—N2	1.459 (3)
C1—Br1	1.900 (2)	C9—H9A	0.98
C2—C3	1.382 (4)	C9—H9B	0.98
C2—H2	0.95	C9—H9C	0.98
C3—C4	1.388 (4)	C10—C11	1.375 (4)
C3—H3	0.95	C10—C15	1.387 (4)
C4—C5	1.386 (4)	C10—N2	1.424 (3)
C4—N1	1.429 (3)	C11—C12	1.388 (4)
C5—C6	1.383 (4)	C11—H11	0.95
C5—H5	0.95	C12—C13	1.379 (4)
C6—H6	0.95	C12—H12	0.95
C7—N1	1.466 (3)	C13—C14	1.371 (4)
C7—H7A	0.98	C13—Br2	1.894 (2)
C7—H7B	0.98	C14—C15	1.383 (4)
C7—H7C	0.98	C14—H14	0.95
C8—O2	1.227 (3)	C15—H15	0.95
C8—N1	1.373 (3)	Br1—Br2ⁱ	3.4443 (4)

C2—C1—C6	121.8 (2)	N2—C9—H9C	109.5
C2—C1—Br1	119.0 (2)	H9A—C9—H9C	109.5
C6—C1—Br1	119.2 (2)	H9B—C9—H9C	109.5
C1—C2—C3	119.3 (2)	C11—C10—C15	119.5 (2)
C1—C2—H2	120.3	C11—C10—N2	121.4 (2)
C3—C2—H2	120.3	C15—C10—N2	119.1 (2)
C2—C3—C4	119.9 (2)	C10—C11—C12	120.1 (2)
C2—C3—H3	120	C10—C11—H11	119.9
C4—C3—H3	120	C12—C11—H11	119.9
C5—C4—C3	119.6 (2)	C13—C12—C11	119.2 (2)
C5—C4—N1	119.9 (2)	C13—C12—H12	120.4
C3—C4—N1	120.5 (2)	C11—C12—H12	120.4
C6—C5—C4	120.8 (2)	C14—C13—C12	121.7 (2)
C6—C5—H5	119.6	C14—C13—Br2	118.9 (2)
C4—C5—H5	119.6	C12—C13—Br2	119.4 (2)
C1—C6—C5	118.4 (2)	C13—C14—C15	118.4 (2)
C1—C6—H6	120.8	C13—C14—H14	120.8
C5—C6—H6	120.8	C15—C14—H14	120.8
N1—C7—H7A	109.5	C14—C15—C10	121.1 (2)
N1—C7—H7B	109.5	C14—C15—H15	119.5
H7A—C7—H7B	109.5	C10—C15—H15	119.5
N1—C7—H7C	109.5	C8—N1—C4	122.8 (2)
H7A—C7—H7C	109.5	C8—N1—C7	116.5 (2)
H7B—C7—H7C	109.5	C4—N1—C7	116.2 (2)
O2—C8—N1	121.7 (2)	C8—N2—C10	124.0 (2)
O2—C8—N2	121.5 (2)	C8—N2—C9	117.6 (2)
N1—C8—N2	116.8 (2)	C10—N2—C9	117.4 (2)
N2—C9—H9A	109.5	C1—Br1—Br2ⁱ	176.83 (8)
N2—C9—H9B	109.5	C13—Br2—Br1ⁱ	90.26 (8)
H9A—C9—H9B	109.5

Symmetry code: (i) −x+3/2, y−1/2, −z+1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···O2ⁱⁱ	0.95	2.59	3.526 (3)	170
C11—H11···O2ⁱⁱⁱ	0.95	2.42	3.365 (3)	178

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

Funding information

The Association France Alzheimer and the Région Midi Pyrénées are acknowledged for financial support (PhD funding for AP).

References

Agilent (2014). CrysAlis PRO. Agilent Technologies, Yarnton, England. Google Scholar
Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435. CrossRef Web of Science IUCr Journals Google Scholar
Clayden, J., Hennecke, U., Vincent, M. A., Hillier, I. H. & Helliwell, M. (2010). Phys. Chem. Chem. Phys. 12, 15056–15064. Web of Science CSD CrossRef CAS PubMed Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CSD CrossRef IUCr Journals Google Scholar
Hisamatsu, S., Masu, H., Azumaya, I., Takahashi, M., Kishikawa, K. & Kohmoto, S. (2011a). Cryst. Growth Des. 11, 1453–1457. Web of Science CSD CrossRef CAS Google Scholar
Hisamatsu, S., Masu, H., Azumaya, I., Takahashi, M., Kishikawa, K. & Kohmoto, S. (2011b). Cryst. Growth Des. 11, 5387–5395. Web of Science CSD CrossRef CAS Google Scholar
Hisamatsu, S., Masu, H., Takahashi, M., Kishikawa, K. & Kohmoto, S. (2012). Tetrahedron Lett. 53, 3903–3906. Web of Science CSD CrossRef CAS Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Snape, T. J., Karakoula, K., Rowther, F. & Warr, T. (2012). RSC Adv. 2, 7557–7560. Web of Science CSD CrossRef CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.