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

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

doi:10.1107/S160053681302401X

organic compounds

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Volume 69| Part 10| October 2013| Page o1536

doi:10.1107/S160053681302401X

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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 and M. Mahendra ^a ^*

^aDepartment of Studies in Physics, Manasagangotri, University of Mysore, Mysore 570 006, India, and ^bDepartment of Chemistry, Central College Campus, Bangalore University, Bangalore 560 001, India
^*Correspondence e-mail: mahendra@physics.uni-mysore.ac.in

(Received 20 August 2013; accepted 27 August 2013; online 12 September 2013)

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 ).

Experimental

Crystal data

C₁₁H₆F₃N₃O
M_r = 253.19
Monoclinic, C 2/c
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[F² > 2σ(F²)] = 0.050
wR(F²) = 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

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
Symmetry code: (i) $[-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

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.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681302401X/ff2117sup1.cif

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

Supporting information file. DOI: 10.1107/S160053681302401X/ff2117Isup3.cml

checkCIF report

Comment top

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.

Related literature top

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).

Experimental top

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).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); 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 (Sheldrick, 2008).

Figures top

	Fig. 1. Perspective diagram of the molecule with 50% probability displacement ellipsoids.
	Fig. 2. Packing diagram of the molecule viewed down the c axis.

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

Crystal data top

C₁₁H₆F₃N₃O	F(000) = 1024
M_r = 253.19	D_x = 1.612 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1846 reflections
a = 20.940 (3) Å	θ = 1.8–25.0°
b = 13.760 (3) Å	µ = 0.14 mm⁻¹
c = 7.2852 (11) Å	T = 273 K
β = 96.369 (4)°	Block, yellow
V = 2086.2 (6) Å³	0.30 × 0.25 × 0.20 mm
Z = 8

Data collection top

Bruker APEXII CCD area-detector diffractometer	R_int = 0.022
ω and ϕ scans	θ_max = 25.0°, θ_min = 1.8°
9665 measured reflections	h = −24→24
1846 independent reflections	k = −16→16
1603 reflections with I > 2σ(I)	l = −8→8

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.050	H-atom parameters constrained
wR(F²) = 0.143	w = 1/[σ²(F_o²) + (0.0749P)² + 1.7218P] where P = (F_o² + 2F_c²)/3
S = 1.06	(Δ/σ)_max < 0.001
1846 reflections	Δρ_max = 0.42 e Å⁻³
164 parameters	Δρ_min = −0.37 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), FC^*=KFC[1+0.001XFC²Λ³/SIN(2Θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0057 (9)

Crystal data top

C₁₁H₆F₃N₃O	V = 2086.2 (6) Å³
M_r = 253.19	Z = 8
Monoclinic, C2/c	Mo Kα radiation
a = 20.940 (3) Å	µ = 0.14 mm⁻¹
b = 13.760 (3) Å	T = 273 K
c = 7.2852 (11) Å	0.30 × 0.25 × 0.20 mm
β = 96.369 (4)°

Data collection top

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

Refinement top

R[F² > 2σ(F²)] = 0.050	0 restraints
wR(F²) = 0.143	H-atom parameters constrained
S = 1.06	Δρ_max = 0.42 e Å⁻³
1846 reflections	Δρ_min = −0.37 e Å⁻³
164 parameters

Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F² for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > σ(F²) is used only for calculating -R-factor-obs etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

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

	x	y	z	U_iso*/U_eq
F16	0.47675 (10)	0.39833 (15)	0.5311 (4)	0.1414 (12)
F17	0.42292 (10)	0.28999 (15)	0.6463 (3)	0.1136 (9)
F18	0.45363 (9)	0.26760 (18)	0.3881 (3)	0.1191 (9)
O15	0.29126 (9)	0.60626 (10)	0.2890 (3)	0.0714 (6)
N1	0.21914 (9)	0.30385 (11)	0.1890 (2)	0.0536 (6)
N8	0.25963 (8)	0.44972 (11)	0.2391 (2)	0.0447 (5)
N10	0.32492 (9)	0.31321 (12)	0.3422 (3)	0.0542 (6)
C2	0.17285 (10)	0.36901 (14)	0.1150 (3)	0.0487 (6)
C3	0.11203 (12)	0.35408 (18)	0.0256 (3)	0.0600 (8)
C4	0.07724 (12)	0.43589 (19)	−0.0316 (3)	0.0642 (8)
C5	0.10216 (12)	0.52902 (18)	−0.0013 (3)	0.0630 (8)
C6	0.16278 (11)	0.54443 (15)	0.0884 (3)	0.0543 (7)
C7	0.19775 (10)	0.46220 (13)	0.1455 (3)	0.0456 (6)
C9	0.27155 (10)	0.35158 (13)	0.2628 (3)	0.0469 (6)
C11	0.36977 (11)	0.37977 (15)	0.4020 (3)	0.0539 (7)
C12	0.43075 (12)	0.33566 (19)	0.4922 (4)	0.0703 (9)
C13	0.36306 (11)	0.47831 (15)	0.3890 (3)	0.0559 (7)
C14	0.30517 (11)	0.51983 (13)	0.3069 (3)	0.0508 (7)
H1	0.21480	0.24170	0.18780	0.0640*
H3	0.09530	0.29190	0.00490	0.0720*
H4	0.03600	0.42860	−0.09210	0.0770*
H5	0.07720	0.58230	−0.04260	0.0760*
H6	0.17940	0.60660	0.10930	0.0650*
H13	0.39690	0.51840	0.43460	0.0670*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
F16	0.0922 (14)	0.0935 (14)	0.221 (3)	−0.0293 (11)	−0.0608 (16)	0.0449 (15)
F17	0.1047 (14)	0.1321 (17)	0.1016 (13)	0.0193 (12)	0.0007 (10)	0.0543 (12)
F18	0.0868 (12)	0.1397 (18)	0.1283 (16)	0.0457 (12)	0.0013 (11)	−0.0196 (14)
O15	0.0854 (12)	0.0276 (7)	0.1030 (13)	−0.0046 (7)	0.0190 (10)	−0.0015 (7)
N1	0.0663 (11)	0.0265 (8)	0.0674 (11)	−0.0028 (7)	0.0048 (9)	−0.0015 (7)
N8	0.0584 (10)	0.0277 (8)	0.0497 (9)	−0.0007 (7)	0.0139 (7)	−0.0005 (6)
N10	0.0630 (11)	0.0337 (9)	0.0653 (11)	0.0000 (8)	0.0046 (9)	0.0000 (7)
C2	0.0595 (12)	0.0390 (10)	0.0489 (11)	0.0001 (8)	0.0118 (9)	0.0002 (8)
C3	0.0668 (14)	0.0560 (13)	0.0573 (12)	−0.0062 (11)	0.0079 (11)	−0.0034 (10)
C4	0.0621 (14)	0.0758 (16)	0.0549 (13)	0.0070 (12)	0.0071 (10)	0.0027 (11)
C5	0.0699 (15)	0.0645 (15)	0.0564 (13)	0.0181 (11)	0.0154 (11)	0.0111 (10)
C6	0.0710 (14)	0.0396 (10)	0.0554 (12)	0.0065 (9)	0.0208 (10)	0.0047 (9)
C7	0.0576 (12)	0.0371 (10)	0.0446 (10)	0.0020 (8)	0.0162 (9)	0.0010 (8)
C9	0.0609 (12)	0.0282 (9)	0.0527 (11)	−0.0008 (8)	0.0106 (9)	−0.0004 (8)
C11	0.0632 (13)	0.0455 (11)	0.0536 (12)	−0.0033 (9)	0.0089 (10)	0.0026 (9)
C12	0.0673 (15)	0.0603 (14)	0.0817 (17)	−0.0031 (12)	0.0017 (13)	0.0072 (13)
C13	0.0650 (13)	0.0440 (11)	0.0592 (12)	−0.0128 (10)	0.0093 (10)	−0.0030 (9)
C14	0.0674 (13)	0.0311 (10)	0.0565 (11)	−0.0066 (9)	0.0189 (10)	−0.0023 (8)

Geometric parameters (Å, º) top

F16—C12	1.301 (3)	C2—C7	1.393 (3)
F17—C12	1.313 (4)	C3—C4	1.380 (4)
F18—C12	1.328 (4)	C4—C5	1.392 (4)
O15—C14	1.228 (2)	C5—C6	1.378 (3)
N1—C2	1.385 (3)	C6—C7	1.386 (3)
N1—C9	1.339 (3)	C11—C13	1.365 (3)
N8—C7	1.406 (3)	C11—C12	1.498 (3)
N8—C9	1.381 (2)	C13—C14	1.412 (3)
N8—C14	1.407 (3)	C3—H3	0.9300
N10—C9	1.311 (3)	C4—H4	0.9300
N10—C11	1.349 (3)	C5—H5	0.9300
N1—H1	0.8600	C6—H6	0.9300
C2—C3	1.380 (3)	C13—H13	0.9300

F16···F16ⁱ	3.013 (3)	C5···C4^vi	3.551 (3)
F17···N10	2.866 (3)	C5···C7^vii	3.433 (3)
F17···C3ⁱⁱ	3.251 (3)	C6···C4^vi	3.471 (3)
F18···F18ⁱⁱⁱ	2.947 (3)	C6···O15	3.037 (3)
F18···N10	2.751 (3)	C6···N8^vii	3.426 (3)
F16···H13ⁱ	2.8700	C6···C5^vi	3.523 (3)
F16···H13	2.4000	C6···C7^vii	3.388 (3)
F17···H3ⁱⁱ	2.8400	C7···C5^vi	3.433 (3)
O15···C6	3.037 (3)	C7···C6^vi	3.388 (3)
O15···N1^iv	2.734 (2)	C7···C14^vii	3.527 (3)
O15···H6	2.5500	C13···C14^vi	3.400 (3)
O15···H1^iv	1.8800	C14···N8^vi	3.415 (3)
N1···N8	2.194 (2)	C14···C13^vii	3.400 (3)
N1···O15^v	2.734 (2)	C14···C7^vi	3.527 (3)
N8···N1	2.194 (2)	C5···H4^viii	3.1000
N8···C6^vi	3.426 (3)	C14···H6	3.1000
N8···C14^vii	3.415 (3)	C14···H1^iv	3.0800
N10···F17	2.866 (3)	H1···O15^v	1.8800
N10···F18	2.751 (3)	H1···C14^v	3.0800
N10···H6^v	2.8700	H3···F17ⁱⁱ	2.8400
C2···C5^vi	3.591 (3)	H4···C5^viii	3.1000
C3···F17ⁱⁱ	3.251 (3)	H6···O15	2.5500
C4···C5^vii	3.551 (3)	H6···C14	3.1000
C4···C6^vii	3.471 (3)	H6···N10^iv	2.8700
C5···C6^vii	3.523 (3)	H13···F16	2.4000
C5···C2^vii	3.591 (3)	H13···F16ⁱ	2.8700

C2—N1—C9	110.23 (16)	N10—C11—C12	113.30 (19)
C7—N8—C9	108.92 (16)	F16—C12—C11	113.7 (2)
C7—N8—C14	129.70 (16)	F16—C12—F17	106.9 (3)
C9—N8—C14	121.38 (17)	F16—C12—F18	106.7 (2)
C9—N10—C11	113.45 (17)	F18—C12—C11	112.3 (2)
C2—N1—H1	125.00	F17—C12—F18	103.8 (2)
C9—N1—H1	125.00	F17—C12—C11	112.8 (2)
N1—C2—C3	131.05 (19)	C11—C13—C14	120.6 (2)
N1—C2—C7	107.49 (18)	N8—C14—C13	112.83 (16)
C3—C2—C7	121.5 (2)	O15—C14—N8	118.9 (2)
C2—C3—C4	116.7 (2)	O15—C14—C13	128.3 (2)
C3—C4—C5	121.8 (2)	C2—C3—H3	122.00
C4—C5—C6	121.8 (2)	C4—C3—H3	122.00
C5—C6—C7	116.4 (2)	C3—C4—H4	119.00
N8—C7—C2	105.87 (16)	C5—C4—H4	119.00
N8—C7—C6	132.28 (18)	C4—C5—H5	119.00
C2—C7—C6	121.9 (2)	C6—C5—H5	119.00
N1—C9—N8	107.50 (17)	C5—C6—H6	122.00
N8—C9—N10	125.63 (18)	C7—C6—H6	122.00
N1—C9—N10	126.87 (17)	C11—C13—H13	120.00
N10—C11—C13	126.1 (2)	C14—C13—H13	120.00
C12—C11—C13	120.6 (2)

C9—N1—C2—C3	179.8 (2)	C7—C2—C3—C4	−0.1 (3)
C9—N1—C2—C7	−0.4 (2)	N1—C2—C7—N8	0.0 (2)
C2—N1—C9—N8	0.6 (2)	N1—C2—C7—C6	−179.6 (2)
C2—N1—C9—N10	−178.9 (2)	C3—C2—C7—N8	179.80 (19)
C9—N8—C7—C2	0.4 (2)	C3—C2—C7—C6	0.2 (3)
C9—N8—C7—C6	179.9 (2)	C2—C3—C4—C5	0.2 (3)
C14—N8—C7—C2	−178.33 (19)	C3—C4—C5—C6	−0.4 (4)
C14—N8—C7—C6	1.2 (4)	C4—C5—C6—C7	0.5 (3)
C7—N8—C9—N1	−0.6 (2)	C5—C6—C7—N8	−179.9 (2)
C7—N8—C9—N10	178.9 (2)	C5—C6—C7—C2	−0.4 (3)
C14—N8—C9—N1	178.23 (17)	N10—C11—C12—F16	172.5 (2)
C14—N8—C9—N10	−2.2 (3)	N10—C11—C12—F17	−65.5 (3)
C7—N8—C14—O15	1.5 (3)	N10—C11—C12—F18	51.3 (3)
C7—N8—C14—C13	−178.26 (19)	C13—C11—C12—F16	−8.5 (4)
C9—N8—C14—O15	−177.0 (2)	C13—C11—C12—F17	113.5 (3)
C9—N8—C14—C13	3.2 (3)	C13—C11—C12—F18	−129.7 (2)
C11—N10—C9—N1	179.3 (2)	N10—C11—C13—C14	−0.1 (4)
C11—N10—C9—N8	−0.1 (3)	C12—C11—C13—C14	−178.9 (2)
C9—N10—C11—C12	−179.9 (2)	C11—C13—C14—O15	178.1 (2)
C9—N10—C11—C13	1.3 (3)	C11—C13—C14—N8	−2.1 (3)
N1—C2—C3—C4	179.7 (2)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+1/2, −y+1/2, −z+1; (iii) −x+1, y, −z+1/2; (iv) −x+1/2, y+1/2, −z+1/2; (v) −x+1/2, y−1/2, −z+1/2; (vi) x, −y+1, z+1/2; (vii) x, −y+1, z−1/2; (viii) −x, −y+1, −z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O15^v	0.86	1.88	2.734 (2)	174
C6—H6···O15	0.93	2.55	3.037 (3)	113
C13—H13···F16	0.93	2.40	2.721 (3)	100

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O15ⁱ	0.8600	1.8800	2.734 (2)	174.00

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

Acknowledgements

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.

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