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Acta Crystallogr Sect E Struct Rep Online. 2010 October 1; 66(Pt 10): o2642.
Published online 2010 September 25. doi:  10.1107/S1600536810037712
PMCID: PMC2983298

Ethyl 7-(2-chloro­phen­yl)-5-trifluoro­meth­yl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine-6-carboxyl­ate

Abstract

In the title compound, C15H12ClF3N4O2, the dihydro­pyrimidine ring exhibits an envelope conformation. The dihedral angle between the mean planes of the dihydro­pyrimidine and phenyl rings is 83.94 (6)°. The OCH2CH3 group is disordered over two sites with occupancies of 0.155 (3) and 0.845 (3). The crystal packing is stabilized by inter­molecular N—H(...)N hydrogen bonds.

Related literature

For the anti­cancer activity, inhibition of the MDM2-p53 protein–protein inter­action and the anti­tuberculosis and dehydrogenase inhibitory activity of [1,2,4]triazolo [1,5-a]pyrimidine derivatives, see: Zhang et al. (2007 [triangle]); Allen et al. (2009 [triangle]); Pereyaslavskaya et al. (2008 [triangle]); Gujjar et al. (2009 [triangle]). For the bioactivity of trifluoro­methyl­ated mol­ecules, see: Kirk, (2006 [triangle]). For the preparation of trifluoro­methyl­ated [1,2,4]triazolo[1,5-a]pyrimidine derivatives, see Pryadeina et al. (2004 [triangle]). For puckering parameters, see: Cremer & Pople (1975 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-o2642-scheme1.jpg

Experimental

Crystal data

  • C15H12ClF3N4O2
  • M r = 372.74
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-o2642-efi1.jpg
  • a = 9.8927 (12) Å
  • b = 6.8055 (6) Å
  • c = 24.403 (3) Å
  • β = 99.237 (9)°
  • V = 1621.6 (3) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.29 mm−1
  • T = 113 K
  • 0.26 × 0.22 × 0.20 mm

Data collection

  • Rigaku Saturn diffractometer
  • Absorption correction: multi-scan (CrystalClear;Rigaku/MSC, 2002 [triangle]) T min = 0.930, T max = 0.945
  • 14364 measured reflections
  • 3835 independent reflections
  • 3058 reflections with I > 2σ(I)
  • R int = 0.043

Refinement

  • R[F 2 > 2σ(F 2)] = 0.047
  • wR(F 2) = 0.121
  • S = 1.08
  • 3835 reflections
  • 242 parameters
  • 6 restraints
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.27 e Å−3
  • Δρmin = −0.40 e Å−3

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

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810037712/hg2715sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810037712/hg2715Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

This work was supported by the Special Fund for the President’s Project (Project 2009 KJZ20) of Xuzhou Medical College.

supplementary crystallographic information

Comment

1,2,4-Triazolo[1,5-a]pyrimidine derivatives are known because of their wide range of biological activities. For example, some of the trizaolopyrimidines can be used as anticancer agents (Zhang et al., 2007), inhibitor of the MDM2-p53 protein-protein interaction (Allen et al., 2009), antituberculosis agents (Pereyaslavskaya et al., 2008) and dehydrogenase inhibitors (Gujjar et al., 2009). Therefore, the preparation or structural modification of these nitrogen-containing heterocyclic scaffolds is of considerable interest for both organic and medicinal chemistry. The introduction of a trifluoromethyl group into organic molecules often changes their physical, chemical, and physiological properties (Kirk, 2006). During the synthesis of trifluoromethylated 1,2,4-Triazolo[1,5-a]pyrimidine derivatives, the title compound (I) was isolated and its structure was determined by X-ray analysis. The results are presented here.

In the title molecule (Fig. 1), the 1,2,4-triazole ring adopts a planar conformation. Cremer & Pople puckering analysis (Cremer &Pople, 1975) can not be performed, for its weighted average absolute torsion angle is 0.7°, less than 5.0°. The dihydropyrimidine ring system is in an envelope conformation, for Cremer & Pople puckering analysis shows θ(2) and [var phi](2) are 0.094 (2)Å and 346.4 (10)°, respectively. Its puckering amplitude (Q) is 0.099 (2)Å. Besides, the distance between atom C2 and the mean N2/C1/N1/C4/C3 plane (r.m.s. deviation 0.016 Å) is 0.136 (2) Å, which also confirms the conformation of the dihydropyrimidine ring. The dihedral angle between the aforementioned weighted plane and phenyl ring is 83.94 (6)°, which shows the two units are nearly perpendicular.

The crystal packing is stabilized by intermolecular N—H···N hydrogen bonds (Table 1, Fig.2).

Experimental

The title compound was synthesized according the procedure reported by Pryadeina et al. (2004). A mixture of 0.01 mol of ethyl 4,4,4-trifluoro-3-oxobutanoate, 0.01 mol of 2-chlorobenzaldehyde and 0.01 mol of 1H-1,2,4-triazol-5-amine in 20 mL of ethanol containing a catalytic amount of hydrochloric acid was heated for 12 h under reflux. Then the solvent was removed under reduced pressure. The residue was added to a solution of p-toluenesulfonic acid, 0.05 g, in 100 mL of benzene, and the mixture was heated for 8 h with simultaneous removal of water as azeotrope with benzene. The solution was filtered while hot, the filtrate was evaporated, and the precipitate was recrystallized from ethanol. Cooling the ethanol solution slowly gave single crystals suitable for X-ray diffraction.

Refinement

The H atoms bound to N atoms were located in a difference map and were refined freely [refined N–H length, 0.90 (2)Å]. All other H atoms were placed in calculated positions, with C–H = 0.95, 0.98, 0.99 or 1.00 Å, and included in the final cycles of refinement using a riding model, with Uiso(H) = 1.2Ueq(parent atom). The OCH2CH3 group is disordered over two sites with occupancies of 0.155 (3) and 0.845 (3). The atom pairs of C12 and C12', C13 and C13', and O2 and O2' are constrained to have the same anisotropic displacement parameters. The bond lengths of ethyl group of C12–C13 and C12'–C13' is restrained to 1.54Å with esd of 0.01Å. The distance between O2 and C12, O2' and C12' is restrained to 1.42Å with esd of 0.01Å. The atoms of O2 and O2' are restrained to be at the distance of 1.38Å from the atom of C11 with esd of 0.01Å.

Figures

Fig. 1.
The molecular structure of the title compound, showing 30% probability displacement ellipsoids and the atom-numbering scheme. The minor part of the disordered moieties were omitted for clarity.
Fig. 2.
A packing diagram of the title compound. Intermolecular hydrogen bonds are shown as dashed lines. The minor part of the disordered moieties were omitted for clarity.

Crystal data

C15H12ClF3N4O2F(000) = 760
Mr = 372.74Dx = 1.527 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71070 Å
Hall symbol: -P 2ynCell parameters from 3832 reflections
a = 9.8927 (12) Åθ = 2.4–27.9°
b = 6.8055 (6) ŵ = 0.28 mm1
c = 24.403 (3) ÅT = 113 K
β = 99.237 (9)°Block, colorless
V = 1621.6 (3) Å30.26 × 0.22 × 0.20 mm
Z = 4

Data collection

Rigaku Saturn diffractometer3835 independent reflections
Radiation source: rotating anode3058 reflections with I > 2σ(I)
confocalRint = 0.043
Detector resolution: 7.31 pixels mm-1θmax = 27.9°, θmin = 2.4°
ω scansh = −13→13
Absorption correction: multi-scan CrystalCleark = −8→8
Tmin = 0.930, Tmax = 0.945l = −32→32
14364 measured reflections

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.047Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.121H atoms treated by a mixture of independent and constrained refinement
S = 1.08w = 1/[σ2(Fo2) + (0.0596P)2 + 0.2191P] where P = (Fo2 + 2Fc2)/3
3835 reflections(Δ/σ)max = 0.001
242 parametersΔρmax = 0.27 e Å3
6 restraintsΔρmin = −0.40 e Å3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) 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)

xyzUiso*/UeqOcc. (<1)
Cl1−0.02142 (6)1.41310 (7)0.14247 (2)0.04311 (18)
F10.35904 (10)0.54406 (16)0.01321 (5)0.0375 (3)
F20.44949 (11)0.82808 (16)0.01419 (5)0.0334 (3)
F30.47647 (11)0.65227 (16)0.08811 (5)0.0329 (3)
O10.33660 (14)1.2697 (2)0.11875 (6)0.0369 (3)
N10.14288 (14)0.6813 (2)0.03869 (6)0.0211 (3)
N20.00227 (14)0.9257 (2)0.06666 (6)0.0213 (3)
N3−0.13449 (15)0.9673 (2)0.06434 (6)0.0261 (3)
N4−0.10446 (14)0.6764 (2)0.02200 (6)0.0228 (3)
C10.01658 (17)0.7543 (2)0.04212 (7)0.0198 (3)
C20.11062 (17)1.0474 (2)0.09691 (7)0.0205 (3)
H20.10031.18420.08190.025*
C30.24727 (17)0.9649 (2)0.08603 (7)0.0215 (4)
C40.25580 (16)0.7931 (2)0.05905 (7)0.0199 (3)
C50.09913 (17)1.0529 (2)0.15815 (7)0.0217 (4)
C60.04123 (19)1.2105 (3)0.18215 (8)0.0274 (4)
C70.0304 (2)1.2109 (3)0.23816 (8)0.0356 (5)
H7−0.00831.32060.25410.043*
C80.0765 (2)1.0501 (3)0.27056 (8)0.0381 (5)
H80.06901.04900.30890.046*
C90.1329 (2)0.8925 (3)0.24762 (8)0.0355 (5)
H90.16440.78230.27000.043*
C100.14409 (19)0.8941 (3)0.19169 (8)0.0284 (4)
H100.18330.78420.17610.034*
C110.36016 (18)1.1040 (3)0.10611 (7)0.0249 (4)
O20.48511 (16)1.0381 (3)0.10610 (10)0.0390 (6)0.845 (3)
C120.5990 (2)1.1697 (4)0.12467 (11)0.0315 (6)0.845 (3)
H12A0.56781.30770.11990.038*0.845 (3)
H12B0.67211.14890.10190.038*0.845 (3)
C130.6540 (3)1.1316 (5)0.18435 (12)0.0518 (8)0.845 (3)
H13A0.58321.16070.20700.078*0.845 (3)
H13B0.73381.21570.19600.078*0.845 (3)
H13C0.68120.99340.18920.078*0.845 (3)
O2'0.4728 (9)0.9900 (15)0.1298 (5)0.0390 (6)0.155 (3)
C12'0.5996 (11)1.0954 (19)0.1454 (7)0.0315 (6)0.155 (3)
H12C0.58601.20560.17040.038*0.155 (3)
H12D0.63091.14990.11200.038*0.155 (3)
C13'0.7072 (14)0.952 (2)0.1752 (7)0.0518 (8)0.155 (3)
H13D0.68470.91900.21170.078*0.155 (3)
H13E0.79791.01330.17960.078*0.155 (3)
H13F0.70760.83170.15300.078*0.155 (3)
C140.38686 (17)0.7050 (2)0.04419 (7)0.0225 (4)
C15−0.19178 (18)0.8142 (3)0.03716 (7)0.0255 (4)
H15−0.28840.80010.02850.031*
H10.146 (2)0.567 (3)0.0203 (9)0.039 (6)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Cl10.0546 (4)0.0261 (3)0.0533 (4)0.0094 (2)0.0228 (3)0.0025 (2)
F10.0217 (6)0.0361 (6)0.0564 (8)−0.0049 (5)0.0118 (5)−0.0233 (5)
F20.0250 (6)0.0366 (6)0.0418 (7)−0.0032 (4)0.0153 (5)0.0102 (5)
F30.0249 (6)0.0370 (6)0.0359 (6)0.0063 (5)0.0023 (5)0.0070 (5)
O10.0310 (8)0.0290 (7)0.0506 (9)−0.0071 (6)0.0063 (6)−0.0098 (6)
N10.0169 (7)0.0207 (7)0.0259 (8)−0.0011 (5)0.0038 (6)−0.0039 (6)
N20.0150 (7)0.0256 (7)0.0231 (7)0.0003 (5)0.0022 (6)−0.0043 (6)
N30.0169 (7)0.0317 (8)0.0293 (8)0.0022 (6)0.0026 (6)−0.0046 (6)
N40.0172 (7)0.0261 (8)0.0245 (8)−0.0008 (6)0.0017 (6)−0.0028 (6)
C10.0175 (8)0.0224 (8)0.0191 (8)−0.0011 (6)0.0022 (6)−0.0002 (6)
C20.0194 (8)0.0210 (8)0.0208 (8)−0.0021 (6)0.0022 (6)−0.0027 (6)
C30.0186 (8)0.0250 (8)0.0207 (8)−0.0015 (7)0.0030 (7)−0.0007 (6)
C40.0168 (8)0.0235 (8)0.0194 (8)−0.0023 (6)0.0030 (6)0.0023 (6)
C50.0177 (8)0.0269 (9)0.0205 (8)−0.0036 (7)0.0027 (7)−0.0028 (7)
C60.0251 (9)0.0283 (9)0.0295 (10)−0.0030 (7)0.0069 (7)−0.0045 (7)
C70.0325 (11)0.0440 (12)0.0329 (11)−0.0062 (9)0.0134 (8)−0.0141 (9)
C80.0311 (11)0.0631 (14)0.0207 (9)−0.0098 (10)0.0057 (8)−0.0034 (9)
C90.0281 (10)0.0525 (12)0.0260 (10)0.0015 (9)0.0043 (8)0.0104 (9)
C100.0249 (9)0.0341 (10)0.0263 (9)0.0022 (8)0.0046 (7)0.0019 (8)
C110.0215 (9)0.0318 (10)0.0217 (9)−0.0031 (7)0.0051 (7)−0.0037 (7)
O20.0174 (8)0.0325 (10)0.0652 (16)−0.0059 (7)0.0001 (8)−0.0180 (10)
C120.0184 (10)0.0282 (14)0.0467 (16)−0.0069 (9)0.0016 (10)−0.0065 (11)
C130.0329 (15)0.070 (2)0.0506 (17)−0.0184 (13)0.0010 (12)−0.0013 (15)
O2'0.0174 (8)0.0325 (10)0.0652 (16)−0.0059 (7)0.0001 (8)−0.0180 (10)
C12'0.0184 (10)0.0282 (14)0.0467 (16)−0.0069 (9)0.0016 (10)−0.0065 (11)
C13'0.0329 (15)0.070 (2)0.0506 (17)−0.0184 (13)0.0010 (12)−0.0013 (15)
C140.0197 (8)0.0227 (8)0.0258 (9)−0.0040 (6)0.0059 (7)−0.0004 (7)
C150.0165 (8)0.0313 (9)0.0282 (9)0.0003 (7)0.0020 (7)−0.0029 (7)

Geometric parameters (Å, °)

Cl1—C61.7407 (19)C7—H70.9500
F1—C141.3339 (19)C8—C91.369 (3)
F2—C141.3293 (19)C8—H80.9500
F3—C141.326 (2)C9—C101.387 (3)
O1—C111.202 (2)C9—H90.9500
N1—C11.359 (2)C10—H100.9500
N1—C41.377 (2)C11—O21.315 (2)
N1—H10.90 (2)C11—O2'1.404 (8)
N2—C11.329 (2)O2—C121.453 (3)
N2—N31.3744 (19)C12—C131.493 (4)
N2—C21.458 (2)C12—H12A0.9900
N3—C151.314 (2)C12—H12B0.9900
N4—C11.329 (2)C13—H13A0.9800
N4—C151.366 (2)C13—H13B0.9800
C2—C51.517 (2)C13—H13C0.9800
C2—C31.526 (2)O2'—C12'1.442 (9)
C2—H21.0000C12'—C13'1.539 (9)
C3—C41.351 (2)C12'—H12C0.9900
C3—C111.486 (2)C12'—H12D0.9900
C4—C141.524 (2)C13'—H13D0.9800
C5—C101.385 (2)C13'—H13E0.9800
C5—C61.389 (2)C13'—H13F0.9800
C6—C71.388 (3)C15—H150.9500
C7—C81.384 (3)
C1—N1—C4118.45 (14)C5—C10—C9121.27 (18)
C1—N1—H1116.7 (14)C5—C10—H10119.4
C4—N1—H1124.6 (14)C9—C10—H10119.4
C1—N2—N3109.72 (13)O1—C11—O2122.77 (17)
C1—N2—C2127.16 (14)O1—C11—O2'125.9 (5)
N3—N2—C2122.86 (13)O2—C11—O2'29.2 (5)
C15—N3—N2101.51 (14)O1—C11—C3121.07 (16)
C1—N4—C15101.41 (14)O2—C11—C3116.05 (16)
N4—C1—N2111.19 (15)O2'—C11—C3106.8 (4)
N4—C1—N1127.88 (15)C11—O2—C12118.11 (18)
N2—C1—N1120.91 (15)O2—C12—C13109.9 (2)
N2—C2—C5110.32 (13)O2—C12—H12A109.7
N2—C2—C3107.61 (13)C13—C12—H12A109.7
C5—C2—C3112.88 (14)O2—C12—H12B109.7
N2—C2—H2108.6C13—C12—H12B109.7
C5—C2—H2108.6H12A—C12—H12B108.2
C3—C2—H2108.6C11—O2'—C12'115.7 (8)
C4—C3—C11127.56 (16)O2'—C12'—C13'108.4 (10)
C4—C3—C2121.99 (15)O2'—C12'—H12C110.0
C11—C3—C2110.36 (14)C13'—C12'—H12C110.0
C3—C4—N1122.93 (16)O2'—C12'—H12D110.0
C3—C4—C14125.36 (15)C13'—C12'—H12D110.0
N1—C4—C14111.62 (14)H12C—C12'—H12D108.4
C10—C5—C6117.92 (16)C12'—C13'—H13D109.5
C10—C5—C2119.70 (15)C12'—C13'—H13E109.5
C6—C5—C2122.36 (15)H13D—C13'—H13E109.5
C7—C6—C5121.26 (18)C12'—C13'—H13F109.5
C7—C6—Cl1117.98 (15)H13D—C13'—H13F109.5
C5—C6—Cl1120.75 (14)H13E—C13'—H13F109.5
C8—C7—C6119.36 (18)F3—C14—F2107.78 (13)
C8—C7—H7120.3F3—C14—F1106.64 (14)
C6—C7—H7120.3F2—C14—F1106.11 (14)
C9—C8—C7120.29 (18)F3—C14—C4113.45 (14)
C9—C8—H8119.9F2—C14—C4111.87 (14)
C7—C8—H8119.9F1—C14—C4110.60 (13)
C8—C9—C10119.89 (19)N3—C15—N4116.16 (15)
C8—C9—H9120.1N3—C15—H15121.9
C10—C9—H9120.1N4—C15—H15121.9
C1—N2—N3—C15−0.87 (18)C2—C5—C6—Cl1−0.2 (2)
C2—N2—N3—C15−175.36 (15)C5—C6—C7—C8−0.9 (3)
C15—N4—C1—N2−0.70 (18)Cl1—C6—C7—C8178.59 (15)
C15—N4—C1—N1−179.05 (17)C6—C7—C8—C90.3 (3)
N3—N2—C1—N41.04 (19)C7—C8—C9—C100.1 (3)
C2—N2—C1—N4175.24 (15)C6—C5—C10—C9−0.5 (3)
N3—N2—C1—N1179.53 (15)C2—C5—C10—C9−178.84 (16)
C2—N2—C1—N1−6.3 (3)C8—C9—C10—C50.0 (3)
C4—N1—C1—N4175.37 (16)C4—C3—C11—O1163.90 (19)
C4—N1—C1—N2−2.8 (2)C2—C3—C11—O1−12.7 (2)
C1—N2—C2—C5−112.47 (18)C4—C3—C11—O2−12.5 (3)
N3—N2—C2—C561.02 (19)C2—C3—C11—O2170.95 (18)
C1—N2—C2—C311.1 (2)C4—C3—C11—O2'−42.3 (6)
N3—N2—C2—C3−175.44 (14)C2—C3—C11—O2'141.1 (6)
N2—C2—C3—C4−8.1 (2)O1—C11—O2—C122.9 (3)
C5—C2—C3—C4113.82 (18)O2'—C11—O2—C12−103.3 (10)
N2—C2—C3—C11168.67 (13)C3—C11—O2—C12179.19 (18)
C5—C2—C3—C11−69.36 (18)C11—O2—C12—C1396.5 (3)
C11—C3—C4—N1−175.26 (16)O1—C11—O2'—C12'−35.7 (14)
C2—C3—C4—N11.0 (3)O2—C11—O2'—C12'58.5 (11)
C11—C3—C4—C140.8 (3)C3—C11—O2'—C12'172.2 (10)
C2—C3—C4—C14177.07 (15)C11—O2'—C12'—C13'174.9 (12)
C1—N1—C4—C35.2 (2)C3—C4—C14—F366.0 (2)
C1—N1—C4—C14−171.36 (14)N1—C4—C14—F3−117.51 (15)
N2—C2—C5—C1077.54 (19)C3—C4—C14—F2−56.2 (2)
C3—C2—C5—C10−42.9 (2)N1—C4—C14—F2120.30 (15)
N2—C2—C5—C6−100.70 (18)C3—C4—C14—F1−174.22 (16)
C3—C2—C5—C6138.88 (17)N1—C4—C14—F12.25 (19)
C10—C5—C6—C70.9 (3)N2—N3—C15—N40.5 (2)
C2—C5—C6—C7179.21 (16)C1—N4—C15—N30.1 (2)
C10—C5—C6—Cl1−178.49 (13)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N1—H1···N4i0.90 (2)1.96 (2)2.843 (2)166.3 (19)

Symmetry codes: (i) −x, −y+1, −z.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HG2715).

References

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