N-(4-Bromo­phen­yl)urea

Petr Štěpnička; Ivana Císařová

doi:10.1107/S1600536810041735

. 2010 Oct 20;66(Pt 11):o2879. doi: 10.1107/S1600536810041735

N-(4-Bromophenyl)urea

Petr Štěpnička ^a,^*, Ivana Císařová ^a

PMCID: PMC3009331 PMID: 21589060

Abstract

In the title compound, C₇H₇BrN₂O, both the urea moiety [maximum deviation 0.003 (2) Å] and the benzene ring are essentially planar [maximum deviation 0.003 (2) Å] but are rotated with respect to each other by a dihedral angle of 47.8 (1)°. The crystal assembly is stabilized by N—H⋯O hydrogen bonds between all NH protons as conventional hydrogen bond donors and the C=O oxygen as a trifurcated hydrogen-bond acceptor. Both the overall molecular geometry and the crystal packing of the title compound are very similar to those of N-phenylurea, which is underscored by a practically isostructural relationship between these two urea derivatives.

Related literature

For the crystal structure of N-phenylurea, see: Kashino & Haisa (1977 ▶); Bott et al. (2000 ▶). For the crystal structure of N-(4-tolyl)urea, see: Ciajolo et al. (1982 ▶). For the structure of a molecular 1:1 adduct of N-(4-bromophenyl)urea with N-(4-bromophenyl)-2-{2-[2-(((4-bromophenyl)carbamoyl)amino)-2-oxoethyl]cyclohex-1-en-1-yl}-2-cyanoacetamide, see: Zhang et al. (2009 ▶).

Experimental

Crystal data

C₇H₇BrN₂O
M _r = 215.06
Monoclinic,
a = 4.6033 (2) Å
b = 5.3915 (2) Å
c = 15.9444 (8) Å
β = 97.994 (3)°
V = 391.87 (3) Å³
Z = 2
Mo Kα radiation
μ = 5.18 mm⁻¹
T = 150 K
0.40 × 0.20 × 0.20 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: gaussian (Coppens, 1970 ▶) T _min = 0.247, T _max = 0.475
5026 measured reflections
1771 independent reflections
1704 reflections with I > 2σ(I)
R _int = 0.037

Refinement

R[F ² > 2σ(F ²)] = 0.023
wR(F ²) = 0.056
S = 1.05
1771 reflections
103 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.30 e Å⁻³
Absolute structure: Flack (1983 ▶), 792 Friedel pairs
Flack parameter: −0.010 (11)

Data collection: COLLECT (Nonius, 2000 ▶); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: HKL DENZO (Otwinowski & Minor, 1997 ▶) and SCALEPACK; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810041735/su2219sup1.cif

e-66-o2879-sup1.cif^{(14.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810041735/su2219Isup2.hkl

e-66-o2879-Isup2.hkl^{(87.2KB, hkl)}

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
N1—H1N⋯O1ⁱ	0.90	2.11	2.904 (3)	146
N2—H2N⋯O1ⁱⁱ	0.90	2.12	2.979 (3)	158
N2—H3N⋯O1ⁱ	0.93	2.12	2.865 (3)	137

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

Financial support from the Ministry of Education of the Czech Republic (project No. MSM0021620857) is gratefully acknowledged.

supplementary crystallographic information

Comment

The title compound crystallized with the symmetry of the monoclinic space group P2₁. Its molecular structure (Fig. 1) compares well to those reported earlier for N-phenylurea (Kashino & Haisa 1977; Bott et al., 2000), N-(4-tolyl)urea (Ciajolo et al., 1982), and mainly to the structure of N-(4-bromophenyl)urea as recently established in the molecular adduct, N-(4-bromophenyl)-2-{2-[2-(((4-bromophenyl)carbamoyl)amino)-2-oxoethyl] cyclohex-1-en-1-yl}-2-cyanoacetamide–N-(4-bromophenyl)urea (1/1) (Zhang et al., 2009).

The four non-hydrogen atoms constituting the urea moiety in the title molecule are coplanar within 0.003 (2) Å, whilst the atoms forming the benzene ring (C1–C6) depart from their mean plane by only 0.002 (3) Å. The Br1 and N1 atoms are displaced from the latter plane by 0.016 (1) Å and 0.053 (2) Å, respectively. Whereas the bromine atoms binds symmetrically to the aromatic ring (the difference in the C(3/5)—C4—Br1 angles is less than 0.1 °), the C1—N1 bond connecting both functional parts is slightly twisted (cf. N1—C1—C2 = 121.5 (2) ° and N1—C1—C6 = 118.8 (3) °). More importantly, the benzene ring and the urea moiety are mutually rotated with a dihedral angle of their mean planes of 47.8 (1) °, which is considerably more than in the afore mentioned adduct (ca 16.5 °), but practically identical with the value reported for N-phenylurea [46.4 and 47.6 ° depending on the study (Kashino & Haisa, 1977; Bott et al., 2000)].

In the crystal, the individual molecules of N-(4-bromophenyl)urea associate predominantly by means of N—H···O hydrogen bonds (Table 1). However, because of the pronounced imbalance in the number of conventional hydrogen bond donors and acceptors, the carbonyl oxygen O1 behaves as a trifurcated hydrogen bond acceptor, interacting with two proximal molecules (Fig. 2a) related by elemental translation along the a-axis and a crystallographic twofold screw axis, respectively. This leads to the formation of layers oriented parallel to the ab plane (Fig. 2b). Notably, the same array is preserved also for N-phenylurea, resulting in similar metrical parameters and the same non-centrosymmetric space group. For N-(4-tolyl)urea, on the other hand, similar hydrogen bonded layers related via a crystallographic inversion centre, leading to the space group P2₁/c and a doubling of the c axis length.

Experimental

The title compound was obtained from the reaction of sodium cyanate with 4-bromoaniline as described in the literature (Pandeya et al., 2000), and was crystallized from hot 90% ethanol. ¹H NMR (399.95 MHz, dmso-d₆): δ 5.91 (s, 2H, NH₂), 7.38 (s, 4H, C₆H₄), 8.66 (s, 1H, NH). ¹³C{¹H} NMR (100.58 MHz, dmso-d₆): δ 112.22 (C_ipso of C₆H₄), 119.52 (2CH of C₆H₄), 131.18 (2CH of C₆H₄), 139.89 (C_ipso of C₆H₄), 155.70 (C═O).