(RS)-(2-Bromo-4-fluoro­anilino)[2-(4,6-dimethoxy­pyrimidin-2-yl­oxy)phen­yl]acetonitrile

Yuan-xiang Li

doi:10.1107/S1600536809033819

. 2009 Aug 29;65(Pt 9):o2295–o2296. doi: 10.1107/S1600536809033819

(RS)-(2-Bromo-4-fluoroanilino)[2-(4,6-dimethoxypyrimidin-2-yloxy)phenyl]acetonitrile

Yuan-xiang Li ^a,^*

PMCID: PMC2970001 PMID: 21577686

Abstract

In the title compound, C₂₀H₁₆BrFN₄O₃, the pyrimidine and 2-bromo-4-fluorophenyl rings are twisted away from the central benzene ring, making dihedral angles of 77.7 (1) and 85.5 (1), respectively. A pair of C—H⋯F interactions is involved in an R ₂ ²(8) motif, linking the molecules into dimers. These ring motifs are situated about the crystallographic centres of symmetry. C—H⋯O hydrogen bonds link the dimers into chains running parallel to [1 Inline graphic 1]. Additionally, a weak C—F⋯π-electron ring interaction was observed in the crystal packing [F⋯Cg = 3.459 (4) Å; Cg is the centroid of the pyrimidine ring]. There is also an intramolecular N—H⋯Br interaction in the structure.

Related literature

Pyrimidinylbenzoates are highly effective herbicides with acetohydroxyacid synthase (AHAS) as a target, see: Duggleby & Pang (2000 ▶). For related structures, see: Li & Huang (2007 ▶); Li & Wang (2007 ▶). For bond-length data, see: Allen et al. (1987 ▶). For graph-set motifs, see: Etter et al. (1990 ▶).

Experimental

Crystal data

C₂₀H₁₆BrFN₄O₃
M _r = 459.28
Triclinic,
a = 8.9131 (4) Å
b = 10.6646 (4) Å
c = 11.7804 (5) Å
α = 67.235 (1)°
β = 82.088 (1)°
γ = 81.277 (2)°
V = 1016.77 (7) Å³
Z = 2
Mo Kα radiation
μ = 2.06 mm⁻¹
T = 299 K
0.25 × 0.20 × 0.20 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.606, T _max = 0.662
10737 measured reflections
4588 independent reflections
2636 reflections with I > 2σ(I)
R _int = 0.027

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.166
S = 1.05
4588 reflections
267 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.83 e Å⁻³
Δρ_min = −0.47 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); 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 global, I. DOI: 10.1107/S1600536809033819/fb2161sup1.cif

e-65-o2295-sup1.cif^{(20.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809033819/fb2161Isup2.hkl

e-65-o2295-Isup2.hkl^{(224.7KB, 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
N4—H4A⋯Br1	0.830 (18)	2.74 (3)	3.065 (2)	105 (3)
C13—H13⋯O3	0.98	2.41	2.763 (3)	101
C17—H17⋯F1ⁱ	0.93	2.61	3.541 (4)	175
C20—H20⋯O3ⁱⁱ	0.93	2.68	3.477 (4)	145
C13—H13⋯O3ⁱⁱ	0.98	2.53	3.433 (3)	153

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

Acknowledgments

The author acknowledges financial support by the Opening Fund of the Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), Hunan Normal University (No. KLCBTCMR2008–05), the Hunan Province Natural Science Foundation of China (No.09 J J6023) and the Scientific Research Foundation of Huaihua University.

supplementary crystallographic information

Comment

Pyrimidine derivatives are rich in various biological properties. In particular, pyrimidinylbenzoates are highly effective herbicides with acetohydroxyacid synthase (AHAS) as a target (Duggleby & Pang, 2000). Here we report the crystal structure of one of such a pyrimidine derivative.

In the title molecule (Fig. 1), the bond lengths and angles are within normal ranges (Allen et al., 1987) being in accordance with the corresponding values in similar compounds (Li & Huang, 2007; Li & Wang, 2007). The pyrimidine (N1//N2//C3—C6) and the benzene rings (C15—C20) are twisted away from the mid-benzene ring (C7—C12) with the dihedral angles equal to 77.7 (1) and 85.4 (1)°, respectively. The interplanar angle between the pyrimidine (N1//N2//C3—C6) and the benzene ring (C15—C20) is only 16.6 (1)°.

Pairs of C—H···F interactions form a graph-set R₂²(8) (Etter et al., 1990) about the crystallographic centres of symmetry, i. e. the molecules form dimers. C-H···O hydrogen bonds link these dimers into one-dimensional chains running parallel to the [111] direction (Fig. 2). Additionally, a weak C—F···π-electron ring interaction is present in the crystal structure (F···Cg = 3.459 (4) Å, C18···Cg = 3.779 (5) Å, C···F···Cg = 92.9 (3)°. (Cg is the centroid of the pyrimidine ring defined by the atoms N1//N2//C3—C6; symmetry code x-1, y, z)). Moreover, there is an intramolecular N-H···Br interaction in the structure (Tab. 1; Fig. 2)).

Experimental

Solution of 2-(4,6-dimethoxypyrimidin-2-yloxy)benzaldehyde (0.26 g, 1 mmol) and 4-bromo-2-fluoroaniline (0.21 g, 1.1 mmol) in 10 ml of methanol was stirred at room temperature for 0.5 h. Then trimethylsilanecarbonitrile (TMSCN) (0.15 g, 1.5 mmol) was added and the reaction mixture was stirred for another 12 h. The resulting mixture was filtered off by suction and the filter cake was washed with little methanol. The crude product was dried under infrared lamp and the title compound was obtained as a white solid (the yield 0.22 g, 74%, melting point: 383–385 K). The product was recrystallized from ethanol at room temperature to give block colourless crystals with average size: 0.20 × 0.15 × 0.10 mm.