organic compounds
Ethyl 7-methyl-2-phenylpyrazolo[1,5-a]pyrimidine-5-carboxylate
aLaboratoire de Chimie Organique Hétérocyclique URAC21, Pôle de Compétences Pharmacochimie, Université Mohammed V-Agdal, Avenue Ibn Battouta, BP 1014, Rabat, Morocco, bInstitut de Chimie Organique et Analytique, Université d'Orléans, UMR CNRS 6005, BP 6759, 45067 Orléans Cedex 2, France, cInstitute of Nanomaterials and Nanotechnology, MASCIR, Rabat, Morocco, and dLaboratoire de Chimie du Solide Appliquée, Université Mohammed V-Agdal, Faculté des Sciences, Avenue Ibn Battouta, BP 1014, Rabat, Morocco
*Correspondence e-mail: i_bassoude@yahoo.fr
The fused pyrazole and pyrimidine rings in the title compound, C16H15N3O2, are almost coplanar, being inclined to one another by 1.31 (12)°. The mean plane of this fused ring system is nearly coplanar with the phenyl ring, as indicated by the dihedral angle between their planes of 1.31 (12)°. The fused-ring system and the phenyl ring are nearly coplanar, as indicated by the dihedral angle of 1.27 (10)°. In the crystal, molecules form inversion dimers via pairs of C—H⋯O hydrogen bonds. C—H⋯N interactions connect the dimers into a three-dimensional network. In addition, π–π contacts are observed, with centroid–centroid distances of 3.426 (2) Å.
Related literature
For pharmacological and biochemical properties of pyrazolo[1,5-a]pyrimidine derivatives, see: Selleri et al. (2005); Almansa et al. (2001); Suzuki et al. (2001); Chen et al. (2004). For related structures, see: Chimichi et al. (1992).
Experimental
Crystal data
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Data collection: APEX2 (Bruker, 2009); cell 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: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: PLATON (Spek, 2009) and publCIF (Westrip, 2010).
Supporting information
https://doi.org/10.1107/S1600536813009902/rz5057sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536813009902/rz5057Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536813009902/rz5057Isup3.cml
A solution of ethyl 2,4-dioxopentanoate (1.64 g, 10.4 mmol) and 5-amino-3-phenylpyrazole (1.5 g, 9.4 mmol) in 10 ml of EtOH was heated to reflux for 30 min. After evaporation of solvent under reduced pressure, the residue was purified on silica gel by
using a 8:2 (v/v) mixture of petroleum ether and ethyl acetate as Ethyl-7-methyl-2-phenylpyrazolo[1,5-a]pyrimidine-5-carboxylate was recrystallized from cyclohexane to give colourless crystals.All H atoms could be located in a difference Fourier map and treated as riding with C—H = 0.93 Å (aromatic), C—H = 0.97 Å (methylene) and C—H = 0.96 Å (methyl), and with Uiso(H) = 1.2 Ueq(aromatic, methylene) or Uiso(H) = 1.5 Ueq (methyl).
Pyrazolo[1,5-a]pyrimidines have attracted considerable interest because of their biological activity. For instance, they are known for their potent utility as selective peripheral benzodiazepine receptor ligands (Selleri et al., 2005), COX-2 selective inhibitors (Almansa et al., 2001), HMG-CoA reductase inhibitors (Suzuki et al., 2001) and CRF1 antagonists (Chen et al., 2004).
The condensation of 5-amino-3-arylpyrazoles with ethyl 2,4-dioxopentanoate leads to the title compound ethyl-7-methyl-2-phenylpyrazolo[1,5-a]pyrimidine- 5-carboxylate and its isomeric ethyl 5-methyl-2-phenylpyrazolo[1,5-a]pyrimidine-7-carboxylate (Chimichi et al., 1992).
The
of the title compound is built up from two fused five and six-membered rings (N1/N2/C2–C4 and N2/N3/C1/C2/C11/C12) linked to a methyl, a phenyl (C5–C10) and to an ethylcarboxylate group (C14/O1/O2/C15/C16) as shown in Fig. 1. The pyrazole and pyrimidine rings are almost planar with a maximum deviation for atom C6 of 0.002 (2) Å and 0.004 (2) Å, respectively. The mean plane through the two fused rings is slightly folded around the common edge as indicated by the dihedral angle between them of 1.31 (12)°. The dihedral angle between the phenyl ring and the fused-ring system is 1.27 (10)°.In the π–π contacts, with centroid–centroid distances of 3.426 (2) Å.
C12–H12···O1 hydrogen bonds form inversion dimers. Intermolecular C6—H6···N3 interactions connect the dimers into a three dimensional network. In addition, the molecules are connected byFor pharmacological and biochemical properties of pyrazolo[1,5-a]pyrimidine derivatives, see: Selleri et al. (2005); Almansa et al. (2001); Suzuki et al. (2001); Chen et al. (2004). For related structures, see: Chimichi et al. (1992).
Data collection: APEX2 (Bruker, 2009); cell
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: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: PLATON (Spek, 2009) and publCIF (Westrip, 2010).C16H15N3O2 | F(000) = 1184 |
Mr = 281.31 | Dx = 1.307 Mg m−3 |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -p 2ac 2ab | Cell parameters from 2783 reflections |
a = 8.0542 (8) Å | θ = 2.5–26.0° |
b = 16.4104 (19) Å | µ = 0.09 mm−1 |
c = 21.635 (2) Å | T = 296 K |
V = 2859.5 (5) Å3 | Block, colourless |
Z = 8 | 0.41 × 0.32 × 0.21 mm |
Bruker X8 APEXII area-detector diffractometer | 1919 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.033 |
Graphite monochromator | θmax = 26.0°, θmin = 2.5° |
φ and ω scans | h = −9→9 |
12894 measured reflections | k = −20→19 |
2783 independent reflections | l = −25→26 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.052 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.170 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0849P)2 + 1.249P] where P = (Fo2 + 2Fc2)/3 |
2783 reflections | (Δ/σ)max < 0.001 |
190 parameters | Δρmax = 0.35 e Å−3 |
0 restraints | Δρmin = −0.36 e Å−3 |
C16H15N3O2 | V = 2859.5 (5) Å3 |
Mr = 281.31 | Z = 8 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 8.0542 (8) Å | µ = 0.09 mm−1 |
b = 16.4104 (19) Å | T = 296 K |
c = 21.635 (2) Å | 0.41 × 0.32 × 0.21 mm |
Bruker X8 APEXII area-detector diffractometer | 1919 reflections with I > 2σ(I) |
12894 measured reflections | Rint = 0.033 |
2783 independent reflections |
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.170 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.35 e Å−3 |
2783 reflections | Δρmin = −0.36 e Å−3 |
190 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.7015 (3) | 0.59846 (13) | −0.00919 (11) | 0.0423 (5) | |
C2 | 0.4533 (2) | 0.62909 (13) | 0.03355 (10) | 0.0392 (5) | |
C3 | 0.2988 (3) | 0.66217 (13) | 0.04562 (11) | 0.0431 (5) | |
H3 | 0.2464 | 0.7041 | 0.0243 | 0.052* | |
C4 | 0.2383 (3) | 0.61938 (13) | 0.09644 (10) | 0.0404 (5) | |
C5 | 0.0780 (3) | 0.63145 (14) | 0.12822 (10) | 0.0426 (5) | |
C6 | −0.0290 (3) | 0.69261 (15) | 0.10875 (12) | 0.0531 (6) | |
H6 | 0.0002 | 0.7255 | 0.0755 | 0.064* | |
C7 | −0.1796 (3) | 0.70489 (17) | 0.13873 (14) | 0.0660 (8) | |
H7 | −0.2511 | 0.7456 | 0.1252 | 0.079* | |
C8 | −0.2234 (4) | 0.65694 (18) | 0.18851 (14) | 0.0689 (8) | |
H8 | −0.3243 | 0.6650 | 0.2085 | 0.083* | |
C9 | −0.1158 (3) | 0.5968 (2) | 0.20843 (13) | 0.0681 (8) | |
H9 | −0.1438 | 0.5649 | 0.2424 | 0.082* | |
C10 | 0.0323 (3) | 0.58363 (17) | 0.17833 (12) | 0.0557 (7) | |
H10 | 0.1025 | 0.5422 | 0.1917 | 0.067* | |
C11 | 0.6159 (3) | 0.52087 (13) | 0.07911 (10) | 0.0423 (5) | |
C12 | 0.7310 (3) | 0.53683 (14) | 0.03464 (11) | 0.0455 (6) | |
H12 | 0.8291 | 0.5070 | 0.0332 | 0.055* | |
C13 | 0.6281 (3) | 0.45638 (16) | 0.12736 (12) | 0.0584 (7) | |
H13A | 0.5308 | 0.4578 | 0.1530 | 0.088* | |
H13B | 0.7247 | 0.4658 | 0.1523 | 0.088* | |
H13C | 0.6365 | 0.4040 | 0.1079 | 0.088* | |
C14 | 0.8285 (3) | 0.61382 (15) | −0.05871 (12) | 0.0493 (6) | |
C15 | 0.8726 (4) | 0.6665 (2) | −0.15930 (14) | 0.0784 (9) | |
H15A | 0.9632 | 0.6276 | −0.1601 | 0.094* | |
H15B | 0.9191 | 0.7208 | −0.1558 | 0.094* | |
C16 | 0.7733 (6) | 0.6597 (3) | −0.21607 (16) | 0.1145 (15) | |
H16A | 0.8427 | 0.6700 | −0.2513 | 0.172* | |
H16B | 0.6848 | 0.6989 | −0.2150 | 0.172* | |
H16C | 0.7276 | 0.6058 | −0.2190 | 0.172* | |
N1 | 0.3450 (2) | 0.56159 (11) | 0.11673 (9) | 0.0435 (5) | |
N2 | 0.4760 (2) | 0.56790 (11) | 0.07779 (8) | 0.0395 (5) | |
N3 | 0.5670 (2) | 0.64421 (11) | −0.01033 (9) | 0.0424 (5) | |
O1 | 0.9709 (2) | 0.59496 (15) | −0.05385 (11) | 0.0868 (7) | |
O2 | 0.76394 (19) | 0.65002 (11) | −0.10746 (8) | 0.0575 (5) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0374 (11) | 0.0394 (12) | 0.0500 (14) | −0.0004 (9) | −0.0033 (9) | −0.0011 (11) |
C2 | 0.0402 (11) | 0.0342 (11) | 0.0432 (13) | −0.0002 (9) | −0.0029 (9) | 0.0031 (10) |
C3 | 0.0424 (11) | 0.0386 (12) | 0.0484 (14) | 0.0045 (9) | 0.0018 (10) | 0.0049 (10) |
C4 | 0.0398 (11) | 0.0401 (11) | 0.0411 (13) | −0.0031 (9) | −0.0021 (9) | −0.0020 (10) |
C5 | 0.0410 (11) | 0.0439 (12) | 0.0429 (13) | −0.0096 (9) | 0.0017 (9) | −0.0050 (11) |
C6 | 0.0491 (13) | 0.0494 (14) | 0.0607 (16) | −0.0019 (11) | 0.0115 (11) | 0.0015 (12) |
C7 | 0.0535 (14) | 0.0578 (16) | 0.087 (2) | 0.0039 (12) | 0.0200 (14) | −0.0032 (16) |
C8 | 0.0566 (16) | 0.074 (2) | 0.076 (2) | −0.0108 (14) | 0.0254 (14) | −0.0131 (17) |
C9 | 0.0625 (16) | 0.083 (2) | 0.0586 (18) | −0.0192 (15) | 0.0127 (13) | 0.0060 (15) |
C10 | 0.0517 (13) | 0.0662 (16) | 0.0492 (15) | −0.0084 (12) | −0.0017 (11) | 0.0072 (13) |
C11 | 0.0392 (11) | 0.0382 (12) | 0.0496 (14) | −0.0004 (9) | −0.0137 (9) | 0.0017 (11) |
C12 | 0.0359 (10) | 0.0436 (13) | 0.0570 (15) | 0.0039 (9) | −0.0077 (10) | −0.0002 (12) |
C13 | 0.0522 (14) | 0.0578 (15) | 0.0650 (17) | 0.0032 (12) | −0.0134 (12) | 0.0171 (13) |
C14 | 0.0387 (12) | 0.0475 (13) | 0.0618 (16) | 0.0016 (10) | 0.0021 (10) | −0.0024 (12) |
C15 | 0.0669 (17) | 0.101 (2) | 0.068 (2) | −0.0081 (17) | 0.0267 (15) | 0.0040 (18) |
C16 | 0.124 (3) | 0.146 (4) | 0.073 (3) | 0.013 (3) | 0.020 (2) | 0.028 (3) |
N1 | 0.0415 (9) | 0.0463 (11) | 0.0428 (11) | −0.0036 (8) | −0.0023 (8) | 0.0023 (9) |
N2 | 0.0384 (9) | 0.0375 (10) | 0.0425 (11) | −0.0020 (7) | −0.0056 (8) | 0.0024 (8) |
N3 | 0.0388 (9) | 0.0402 (10) | 0.0482 (11) | 0.0021 (8) | 0.0031 (8) | 0.0030 (9) |
O1 | 0.0407 (10) | 0.1158 (18) | 0.1039 (17) | 0.0204 (10) | 0.0123 (10) | 0.0295 (14) |
O2 | 0.0442 (9) | 0.0723 (12) | 0.0561 (11) | 0.0020 (8) | 0.0098 (8) | 0.0099 (10) |
C1—N3 | 1.318 (3) | C9—H9 | 0.9300 |
C1—C12 | 1.407 (3) | C10—H10 | 0.9300 |
C1—C14 | 1.503 (3) | C11—C12 | 1.361 (3) |
C2—N3 | 1.342 (3) | C11—N2 | 1.366 (3) |
C2—C3 | 1.383 (3) | C11—C13 | 1.490 (3) |
C2—N2 | 1.399 (3) | C12—H12 | 0.9300 |
C3—C4 | 1.393 (3) | C13—H13A | 0.9600 |
C3—H3 | 0.9300 | C13—H13B | 0.9600 |
C4—N1 | 1.353 (3) | C13—H13C | 0.9600 |
C4—C5 | 1.476 (3) | C14—O1 | 1.192 (3) |
C5—C10 | 1.388 (3) | C14—O2 | 1.318 (3) |
C5—C6 | 1.389 (3) | C15—O2 | 1.448 (3) |
C6—C7 | 1.390 (3) | C15—C16 | 1.470 (5) |
C6—H6 | 0.9300 | C15—H15A | 0.9700 |
C7—C8 | 1.380 (4) | C15—H15B | 0.9700 |
C7—H7 | 0.9300 | C16—H16A | 0.9600 |
C8—C9 | 1.382 (4) | C16—H16B | 0.9600 |
C8—H8 | 0.9300 | C16—H16C | 0.9600 |
C9—C10 | 1.376 (4) | N1—N2 | 1.354 (2) |
N3—C1—C12 | 124.1 (2) | N2—C11—C13 | 118.0 (2) |
N3—C1—C14 | 116.8 (2) | C11—C12—C1 | 120.0 (2) |
C12—C1—C14 | 119.09 (19) | C11—C12—H12 | 120.0 |
N3—C2—C3 | 132.5 (2) | C1—C12—H12 | 120.0 |
N3—C2—N2 | 121.83 (18) | C11—C13—H13A | 109.5 |
C3—C2—N2 | 105.69 (18) | C11—C13—H13B | 109.5 |
C2—C3—C4 | 105.43 (19) | H13A—C13—H13B | 109.5 |
C2—C3—H3 | 127.3 | C11—C13—H13C | 109.5 |
C4—C3—H3 | 127.3 | H13A—C13—H13C | 109.5 |
N1—C4—C3 | 112.77 (19) | H13B—C13—H13C | 109.5 |
N1—C4—C5 | 119.9 (2) | O1—C14—O2 | 124.6 (2) |
C3—C4—C5 | 127.3 (2) | O1—C14—C1 | 123.3 (2) |
C10—C5—C6 | 118.7 (2) | O2—C14—C1 | 112.16 (18) |
C10—C5—C4 | 121.3 (2) | O2—C15—C16 | 107.7 (3) |
C6—C5—C4 | 119.9 (2) | O2—C15—H15A | 110.2 |
C5—C6—C7 | 120.3 (2) | C16—C15—H15A | 110.2 |
C5—C6—H6 | 119.8 | O2—C15—H15B | 110.2 |
C7—C6—H6 | 119.8 | C16—C15—H15B | 110.2 |
C8—C7—C6 | 120.3 (3) | H15A—C15—H15B | 108.5 |
C8—C7—H7 | 119.8 | C15—C16—H16A | 109.5 |
C6—C7—H7 | 119.8 | C15—C16—H16B | 109.5 |
C7—C8—C9 | 119.4 (2) | H16A—C16—H16B | 109.5 |
C7—C8—H8 | 120.3 | C15—C16—H16C | 109.5 |
C9—C8—H8 | 120.3 | H16A—C16—H16C | 109.5 |
C10—C9—C8 | 120.5 (3) | H16B—C16—H16C | 109.5 |
C10—C9—H9 | 119.7 | C4—N1—N2 | 103.87 (17) |
C8—C9—H9 | 119.7 | N1—N2—C11 | 125.91 (18) |
C9—C10—C5 | 120.7 (3) | N1—N2—C2 | 112.24 (16) |
C9—C10—H10 | 119.6 | C11—N2—C2 | 121.85 (18) |
C5—C10—H10 | 119.6 | C1—N3—C2 | 116.24 (19) |
C12—C11—N2 | 115.98 (19) | C14—O2—C15 | 117.8 (2) |
C12—C11—C13 | 126.0 (2) | ||
N3—C2—C3—C4 | 178.2 (2) | N3—C1—C14—O2 | −22.0 (3) |
N2—C2—C3—C4 | 0.3 (2) | C12—C1—C14—O2 | 157.4 (2) |
C2—C3—C4—N1 | −0.2 (3) | C3—C4—N1—N2 | −0.1 (2) |
C2—C3—C4—C5 | 179.4 (2) | C5—C4—N1—N2 | −179.70 (18) |
N1—C4—C5—C10 | −1.1 (3) | C4—N1—N2—C11 | −178.94 (19) |
C3—C4—C5—C10 | 179.3 (2) | C4—N1—N2—C2 | 0.3 (2) |
N1—C4—C5—C6 | 177.8 (2) | C12—C11—N2—N1 | 178.77 (19) |
C3—C4—C5—C6 | −1.8 (3) | C13—C11—N2—N1 | 0.0 (3) |
C10—C5—C6—C7 | −0.6 (4) | C12—C11—N2—C2 | −0.4 (3) |
C4—C5—C6—C7 | −179.4 (2) | C13—C11—N2—C2 | −179.1 (2) |
C5—C6—C7—C8 | 0.6 (4) | N3—C2—N2—N1 | −178.54 (18) |
C6—C7—C8—C9 | 0.3 (4) | C3—C2—N2—N1 | −0.4 (2) |
C7—C8—C9—C10 | −1.2 (4) | N3—C2—N2—C11 | 0.7 (3) |
C8—C9—C10—C5 | 1.3 (4) | C3—C2—N2—C11 | 178.88 (19) |
C6—C5—C10—C9 | −0.4 (4) | C12—C1—N3—C2 | −0.4 (3) |
C4—C5—C10—C9 | 178.5 (2) | C14—C1—N3—C2 | 179.02 (19) |
N2—C11—C12—C1 | −0.3 (3) | C3—C2—N3—C1 | −177.9 (2) |
C13—C11—C12—C1 | 178.3 (2) | N2—C2—N3—C1 | −0.3 (3) |
N3—C1—C12—C11 | 0.7 (3) | O1—C14—O2—C15 | 1.4 (4) |
C14—C1—C12—C11 | −178.7 (2) | C1—C14—O2—C15 | −178.5 (2) |
N3—C1—C14—O1 | 158.1 (3) | C16—C15—O2—C14 | 147.1 (3) |
C12—C1—C14—O1 | −22.5 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
C12—H12···O1i | 0.93 | 2.36 | 3.258 (3) | 161 |
C6—H6···N3ii | 0.93 | 2.62 | 3.507 (3) | 161 |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) x−1/2, −y+3/2, −z. |
Experimental details
Crystal data | |
Chemical formula | C16H15N3O2 |
Mr | 281.31 |
Crystal system, space group | Orthorhombic, Pbca |
Temperature (K) | 296 |
a, b, c (Å) | 8.0542 (8), 16.4104 (19), 21.635 (2) |
V (Å3) | 2859.5 (5) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.41 × 0.32 × 0.21 |
Data collection | |
Diffractometer | Bruker X8 APEXII area-detector |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12894, 2783, 1919 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.170, 1.04 |
No. of reflections | 2783 |
No. of parameters | 190 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.35, −0.36 |
Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 2012), PLATON (Spek, 2009) and publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
C12—H12···O1i | 0.93 | 2.36 | 3.258 (3) | 160.9 |
C6—H6···N3ii | 0.93 | 2.62 | 3.507 (3) | 160.6 |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) x−1/2, −y+3/2, −z. |
Acknowledgements
The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements.
References
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Pyrazolo[1,5-a]pyrimidines have attracted considerable interest because of their biological activity. For instance, they are known for their potent utility as selective peripheral benzodiazepine receptor ligands (Selleri et al., 2005), COX-2 selective inhibitors (Almansa et al., 2001), HMG-CoA reductase inhibitors (Suzuki et al., 2001) and CRF1 antagonists (Chen et al., 2004).
The condensation of 5-amino-3-arylpyrazoles with ethyl 2,4-dioxopentanoate leads to the title compound ethyl-7-methyl-2-phenylpyrazolo[1,5-a]pyrimidine- 5-carboxylate and its isomeric ethyl 5-methyl-2-phenylpyrazolo[1,5-a]pyrimidine-7-carboxylate (Chimichi et al., 1992).
The crystal structure of the title compound is built up from two fused five and six-membered rings (N1/N2/C2–C4 and N2/N3/C1/C2/C11/C12) linked to a methyl, a phenyl (C5–C10) and to an ethylcarboxylate group (C14/O1/O2/C15/C16) as shown in Fig. 1. The pyrazole and pyrimidine rings are almost planar with a maximum deviation for atom C6 of 0.002 (2) Å and 0.004 (2) Å, respectively. The mean plane through the two fused rings is slightly folded around the common edge as indicated by the dihedral angle between them of 1.31 (12)°. The dihedral angle between the phenyl ring and the fused-ring system is 1.27 (10)°.
In the crystal structure C12–H12···O1 hydrogen bonds form inversion dimers. Intermolecular C6—H6···N3 interactions connect the dimers into a three dimensional network. In addition, the molecules are connected by π–π contacts, with centroid–centroid distances of 3.426 (2) Å.