2-Tri­fluoro­methyl-10H-benzo[4,5]imidazo[1,2-a]pyrimidin-4-one

Chandra; K B Puttaraju; K Shivashankar; E A Jithesh Babu; M Mahendra

doi:10.1107/S160053681302401X

. 2013 Sep 12;69(Pt 10):o1536. doi: 10.1107/S160053681302401X

2-Trifluoromethyl-10H-benzo[4,5]imidazo[1,2-a]pyrimidin-4-one

Chandra ^a, K B Puttaraju ^b, K Shivashankar ^b, E A Jithesh Babu ^a, M Mahendra ^a,^*

PMCID: PMC3790404 PMID: 24098223

Abstract

In the molecule of the title compound, C₁₁H₆F₃N₃O, the three fused rings of the benzo[4,5]imidazo[1,2-a]pyrimidine unit are essentially coplanar, the maximum deviation from the mean plane being 0.096 (2) Å. In the crystal, N—H⋯O hydrogen bonds link the molecules into chains running along the b-axis direction.

Related literature

For the bioactivity of benzo[4,5] imidazo[1,2-a]-pyrimidine derivatives, see: Abdel-Hafez (2007 ▶); Nunes et al. (2005 ▶); Duval et al. (2005 ▶); Palacios et al. (2007 ▶); Teimouria & Bazhrang (2006 ▶). For bond-length data, see: Allen et al. (1987 ▶). graphic file with name e-69-o1536-scheme1.jpg

Experimental

Crystal data

C₁₁H₆F₃N₃O
M _r = 253.19
Monoclinic,
a = 20.940 (3) Å
b = 13.760 (3) Å
c = 7.2852 (11) Å
β = 96.369 (4)°
V = 2086.2 (6) Å³
Z = 8
Mo Kα radiation
μ = 0.14 mm⁻¹
T = 273 K
0.30 × 0.25 × 0.20 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
9665 measured reflections
1846 independent reflections
1603 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.050
wR(F ²) = 0.143
S = 1.06
1846 reflections
164 parameters
H-atom parameters constrained
Δρ_max = 0.42 e Å⁻³
Δρ_min = −0.37 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; 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: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681302401X/ff2117sup1.cif

e-69-o1536-sup1.cif^{(18.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681302401X/ff2117Isup2.hkl

e-69-o1536-Isup2.hkl^{(91KB, hkl)}

Click here for additional data file.^{(4.4KB, cml)}

Supplementary material file. DOI: 10.1107/S160053681302401X/ff2117Isup3.cml

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—H1⋯O15ⁱ	0.86	1.88	2.734 (2)	174

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Symmetry code: (i) Inline graphic .

Acknowledgments

Chandra would like to thank the University of Mysore for the award of an RFSMS fellowship under the head DV5/Physics/389/RFSMS/2009–2010/10.07.2012.

supplementary crystallographic information

1. Comment

Benzo[4,5]imidazo[1,2-a]pyrimidin-4-one is a class of fused tricyclic system having three nitrogen atoms. The derivatives of benzopyrimidine are of great importance because of their remarkable biological properties. Some of them have shown good antineoplastic (Abdel-Hafez, 2007) and protein kinase inhibitor (Nunes, Zhu, Amouzegh et al., 2005) activities. Also, heterocycles containing an imidazolone moiety exhibits various biological activities such as antibacterial and antifungal activities (Palacios et al., 2007 and Duval et al., 2005, Teimouria et al., 2006). In view of its extensive background, the title compound was prepared and characterized by single-crystal X-ray diffraction.

In the molecular structure of the title compound (Fig. 1), the bond lengths and angles are generally within normal ranges (Allen et al., 1987). The three fused rings of the benzo[4,5]imidazo[1,2-a]pyrimidine unit are essentially coplanar, the maximum deviation from the mean plane being 0.096 (2) Å for atom O15. The crystal structure is stabilized by an intramolecular C—H···O and intermolecular N—H···O hydrogen bonds. The packing diagram of the molecule exhibits linear chain when viewed down the c axis as shown in Fig. 2.

2. Experimental

An equimolar mixture of 2-aminobenzimadzole (0.5 g, 3.75 mmol) and 4,4,4-Trifluoro-3-oxo-butyric acid ethyl ester (0.69 g, 3.75 mmol) in DMF (10 ml) were added to a microwave tube equipped with a magnetic stir bar. The microwave tube was fitted with a reflux condenser and irradiated in a microwave reactor at a temperature of 130°C for 3 min at a maximum power of 320 W. Then, the reaction mixture was poured on to crushed ice. The solid was filtered and washed with 100 ml of cold water. The crude product was dried and recrystallized from 1:3 ethyl acetate and chloroform to get title compound (Yield = 74%, MP = 223–225°C).