2-Amino-1H-benzoimidazol-3-ium 4,4,4-trifluoro-1,3-dioxo-1-phenyl­butan-2-ide

Gong-Chun Li; Feng-Ling Yang; Chang-Sheng Yao

doi:10.1107/S1600536808037483

. 2008 Nov 26;64(Pt 12):o2460. doi: 10.1107/S1600536808037483

2-Amino-1H-benzoimidazol-3-ium 4,4,4-trifluoro-1,3-dioxo-1-phenylbutan-2-ide

Gong-Chun Li ^a,^*, Feng-Ling Yang ^a, Chang-Sheng Yao ^b

PMCID: PMC2959878 PMID: 21581428

Abstract

In the title compound, C₇H₈N₃ ⁺·C₁₀H₆F₃O₂ ⁻, 1H-benzoimidazol-2-amine system adopts a planar conformation with an r.m.s. deviation of 0.0174 Å. The cation and anion in the asymmetric unit are linked by N—H⋯O hydrogen bonds. There are also additional intermolecular N—H⋯O hydrogen bonds and π–π stacking interactions between the phenyl rings of neighbouring anions with centroid–centroid distances of 4.0976 (13) Å.

Related literature

For details of the bioactivity of organofluorine compounds, see: Hermann et al. (2003 ▶); Ulrich (2004 ▶).

Experimental

Crystal data

C₇H₈N₃ ⁺·C₁₀H₆F₃O₂ ⁻
M _r = 349.31
Orthorhombic,
a = 16.755 (3) Å
b = 10.552 (2) Å
c = 18.497 (4) Å
V = 3270.0 (11) Å³
Z = 8
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 113 (2) K
0.12 × 0.10 × 0.06 mm

Data collection

Rigaku Saturn CCD diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2002 ▶) T _min = 0.986, T _max = 0.993
31132 measured reflections
2881 independent reflections
2609 reflections with I > 2σ(I)
R _int = 0.050

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.107
S = 1.06
2881 reflections
243 parameters
5 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 2002 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808037483/sj2549sup1.cif

e-64-o2460-sup1.cif^{(19.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808037483/sj2549Isup2.hkl

e-64-o2460-Isup2.hkl^{(141.5KB, 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—H1A⋯O2ⁱ	0.877 (9)	2.004 (11)	2.7803 (18)	146.8 (16)
N3—H3A⋯O1ⁱ	0.895 (9)	1.949 (13)	2.7651 (17)	150.9 (19)
N3—H3A⋯O2ⁱ	0.895 (9)	2.363 (18)	2.9912 (18)	127.3 (17)
N1—H1B⋯O1	0.879 (9)	2.030 (10)	2.8662 (18)	158.4 (16)
N2—H2A⋯O2	0.905 (10)	1.862 (11)	2.7360 (18)	161.8 (19)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the Natural Science Foundation of Henan Province, China (grant No. 082300420110) and the Natural Science Foundation of Henan Province Education Department, China (grant No. 2007150036) for financial support.

supplementary crystallographic information

Comment

Compounds that contain fluorine exhibit particular bioactivity, for example, flumioxazin is a widely used herbicide (Hermann et al., 2003; Ulrich,2004). This led us to pay much attention to the synthesis and structure of similar fluoro-compounds. During the synthesis of trifluoromethylated heterocyclic compounds, an intermediate, the title compound,(I), Fig.1, was isolated and we report its crystal structure here.

The 1H-benzo[d]imizol-2-amine cation adopts a planar conformation with an rms deviation of 0.0174 for the fitted atoms. The phenyl ring is almost perpendicular to the fused heterocyclic rings, with a dihedral angle of 81.84 (4)° between them. The cation and anion in the asymmetric unit are linked by N1—H1B···O1 and N2—H2A···O2 hydrogen bonds.

The crystal packing is further stabilized by additional intermolecular N—H···O hydrogen bonds (Table 1, Fig. 2) and intermolecular π···π stacking interactions between the C5-C10 phenyl rings (symmetry code: 2-x, -y, -z) of neighbouring anions with centroid-to-centroid distances, plane-plane distances and displacement distances of 4.0976 (13), 3.786 and 1.565Å respectively.

Experimental

The title compound was synthesized by the reaction of 4,4,4-trifluoro-1- phenylbutane-1,3-dione (1 mmol) and 1H-benzo[d]imidazol-2-amine (1 mmol) in refluxing ethanol (20 mL) for a certain time (monitored by TLC). Cooling, the reaction mixture slowly to room temperature, gave single crystals suitable for X-ray diffraction.