1-Methyl-3-(2-methyl­phen­yl)-4-phenyl-1H-pyrazolo­[3,4-d]pyrimidine

El Hafi, M.; Boulhaoua, M.; Ramli, Y.; Benchidmi, M.; Essassi, E.M.; Mague, J.T.

doi:10.1107/S2414314617013700

organic compounds

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ISSN: 2414-3146

Volume 2| Part 10| October 2017| x171370

https://doi.org/10.1107/S2414314617013700

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1-Methyl-3-(2-methylphenyl)-4-phenyl-1H-pyrazolo[3,4-d]pyrimidine

Mohamed El Hafi,^a ^* Mohammed Boulhaoua,^a Youssef Ramli,^b Mohammed Benchidmi,^a El Mokhtar Essassi ^a and Joel T. Mague ^c

^aLaboratoire de Chimie Organique Hétérocyclique, Centre de Recherche Des Sciences des Médicaments, Pôle de Compétence Pharmacochimie, Av Ibn Battouta, BP 1014, Faculté des Sciences, Université Mohammed V, Rabat, Morocco, ^bLaboratory of Medicinal Chemistry, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco, and ^cDepartment of Chemistry, Tulane University, New Orleans, LA 70118, USA
^*Correspondence e-mail: elhafi.mohamed1@gmail.com

Edited by L. Van Meervelt, Katholieke Universiteit Leuven, Belgium (Received 23 September 2017; accepted 24 September 2017; online 6 October 2017)

In the title compound, C₁₉H₁₆N₄, the pyrazolopyrimidine unit is slightly twisted. A combination of π-stacking and offset π-stacking interactions forms columns along the b-axis direction.

Keywords: crystal structure; pyrimidine; π-stacking; pyrazolo[3,4-d]pyrimidine.

CCDC reference: 1576254

Structure description

Among the various classes of nitrogen containing heterocyclic compounds, pyrazolo[3,4-d]pyrimidine derivatives display a broad spectrum of biological activities, because of their structural resemblance to purine nucleobases. In recent years, researchers have reported the use of purine derivatives of pyrazolo[3,4-d]pyrimidine as kinase inhibitors (Diner et al., 2012 ), antiviral agents (Bektemirov et al., 2010 ) and antitubercular agents (Trivedi et al., 2012 ). The present paper is a continuation of our research work devoted to the development of pyrazolo[3,4-d]pyrimidine derivatives with potential pharmacological activities (El Fal et al., 2013 ).

In the title compound, the pyrazolopyrimidine moiety is slightly twisted, as indicated by the dihedral angle of 3.19 (6)° between the mean planes through the five- and six-membered rings (Fig. 1). The o-tolyl ring is inclined to the pyrazole ring by 57.26 (6)°, while the phenyl ring is inclined to the pyrimidine ring by 33.04 (6)°. In the crystal, π-stacking interactions between pyrimidine rings form centrosymmetric dimers [centroid–centroid = 3.5178 (6) Å], which are formed into stacks along the b-axis direction by offset π-stacking interactions between the C2/N2/C3/N3 portions of the centrosymmetrically related dimers [interplanar spacing = 3.1850 (4) Å; Figs. 2 and 3].

Figure 1
The molecular structure of the title molecule, with the atom-labelling scheme and displacement ellipsoids drawn at the 50% probability level.

Figure 2
Detail of the π-stacking (orange dashed line) and the offset π-stacking (green dashed lines) viewed along the a-axis direction. H atoms have been omitted for clarity.

Figure 3
Packing viewed along the b-axis direction, with the π-stacking interactions shown as orange dashed lines. H atoms have been omitted for clarity.

Synthesis and crystallization

Under an atmosphere of argon, a mixture of 1-methyl-4-phenyl-1H-pyrazolo[3,4-d]pyrimidine (0.1 g, 0.47 mmol), 2-iodotoluene (0.12 ml, 0.94 mmol), Cs₂CO₃ (0.46 g, 1.42 mmol), K₃PO₄ (0.25 g, 1.18 mmol), 1,10-phenanthroline (0.034 g, 0.19 mmol) and Pd(OAc)₂ (0.021 g, 0.094 mmol) in DMA (3 ml) was flushed with argon and heated to 438 K for 48 h. After completion of the reaction, the mixture was allowed to cool to room temperature and the solvent was removed under reduced pressure. Water (15 ml) was added and the resulting aqueous phase was extracted with CH₂Cl₂ (3 × 15 ml). The combined organic layers were dried with MgSO₄ and concentrated under vacuum. The residue was purified by column chromatography on silica gel (EtOAc/petroleum ether). The title compound was recrystallized from ethanol at room temperature, giving colourless crystals (yield 63%; m.p. 405–407 K).

Refinement

Crystal data, data collection and structure refinement details are presented in Table 1.

Table 1
Experimental details

Crystal data
Chemical formula	C₁₉H₁₆N₄
M_r	300.36
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	150
a, b, c (Å)	25.8546 (6), 6.9306 (2), 19.6783 (5)
β (°)	118.658 (1)
V (Å³)	3094.16 (14)
Z	8
Radiation type	Cu Kα
μ (mm⁻¹)	0.62
Crystal size (mm)	0.29 × 0.15 × 0.11

Data collection
Diffractometer	Bruker D8 VENTURE PHOTON 100 CMOS
Absorption correction	Multi-scan (SADABS; Bruker, 2016 )
T_min, T_max	0.85, 0.94
No. of measured, independent and observed [I > 2σ(I)] reflections	11463, 3124, 2874
R_int	0.028
(sin θ/λ)_max (Å⁻¹)	0.625

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.037, 0.100, 1.04
No. of reflections	3124
No. of parameters	273
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.20, −0.20
Computer programs: APEX3 and SAINT (Bruker, 2016), SHELXT (Sheldrick, 2015a ), SHELXL2016 (Sheldrick, 2015b ), DIAMOND (Brandenburg & Putz, 2012 ) and SHELXTL (Sheldrick, 2008 ).

Structural data

CCDC reference: 1576254

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S2414314617013700/vm4028sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617013700/vm4028Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314617013700/vm4028Isup3.cdx

Supporting information file. DOI: https://doi.org/10.1107/S2414314617013700/vm4028Isup4.cml

checkCIF report

Computing details top

Data collection: APEX3 (Bruker, 2016); cell refinement: SAINT (Bruker, 2016); data reduction: SAINT (Bruker, 2016); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015b); molecular graphics: DIAMOND (Brandenburg & Putz, 2012); software used to prepare material for publication: SHELXTL (Bruker, 2016).

1-Methyl-3-(2-methylphenyl)-4-phenyl-1H-pyrazolo[3,4-d]pyrimidine top

Crystal data top

C₁₉H₁₆N₄	F(000) = 1264
M_r = 300.36	D_x = 1.290 Mg m⁻³
Monoclinic, C2/c	Cu Kα radiation, λ = 1.54178 Å
a = 25.8546 (6) Å	Cell parameters from 9566 reflections
b = 6.9306 (2) Å	θ = 5.1–74.5°
c = 19.6783 (5) Å	µ = 0.62 mm⁻¹
β = 118.658 (1)°	T = 150 K
V = 3094.16 (14) Å³	Column, colourless
Z = 8	0.29 × 0.15 × 0.11 mm

Data collection top

Bruker D8 VENTURE PHOTON 100 CMOS diffractometer	3124 independent reflections
Radiation source: INCOATEC IµS micro-focus source	2874 reflections with I > 2σ(I)
Mirror monochromator	R_int = 0.028
Detector resolution: 10.4167 pixels mm^-1	θ_max = 74.5°, θ_min = 5.1°
ω scans	h = −31→31
Absorption correction: multi-scan (SADABS; Bruker, 2016)	k = −8→8
T_min = 0.85, T_max = 0.94	l = −24→22
11463 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.037	All H-atom parameters refined
wR(F²) = 0.100	w = 1/[σ²(F_o²) + (0.0497P)² + 1.7251P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max < 0.001
3124 reflections	Δρ_max = 0.20 e Å⁻³
273 parameters	Δρ_min = −0.20 e Å⁻³
0 restraints	Extinction correction: SHELXL2016 (Sheldrick, 2015b), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.00168 (14)

Special details top

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) top

	x	y	z	U_iso*/U_eq
N1	0.51451 (4)	0.28267 (14)	0.60439 (5)	0.0309 (2)
N2	0.54018 (4)	0.19678 (13)	0.50584 (6)	0.0315 (2)
N3	0.45894 (4)	0.22510 (14)	0.37751 (6)	0.0312 (2)
N4	0.40026 (4)	0.26735 (14)	0.34325 (6)	0.0319 (2)
C1	0.45863 (5)	0.32694 (15)	0.55272 (6)	0.0264 (2)
C2	0.55098 (5)	0.21902 (17)	0.57827 (7)	0.0320 (3)
C3	0.48400 (5)	0.23908 (15)	0.45530 (6)	0.0277 (2)
H3	0.5903 (6)	0.187 (2)	0.6178 (8)	0.031 (3)*
C4	0.48669 (7)	0.1722 (2)	0.33122 (8)	0.0384 (3)
H4A	0.4883 (9)	0.281 (3)	0.3029 (12)	0.076 (6)*
H4B	0.5266 (8)	0.130 (3)	0.3651 (10)	0.053 (5)*
H4C	0.4639 (8)	0.067 (3)	0.2960 (11)	0.062 (5)*
C5	0.38752 (5)	0.31035 (16)	0.39930 (6)	0.0281 (2)
C6	0.43977 (5)	0.29888 (15)	0.47323 (6)	0.0262 (2)
C7	0.42235 (5)	0.40674 (16)	0.58573 (6)	0.0270 (2)
C8	0.43410 (5)	0.34806 (18)	0.65990 (6)	0.0315 (3)
H8	0.4642 (6)	0.250 (2)	0.6866 (8)	0.039 (4)*
C9	0.40480 (6)	0.43019 (19)	0.69569 (7)	0.0361 (3)
H9	0.4154 (7)	0.390 (2)	0.7493 (9)	0.046 (4)*
C10	0.36296 (6)	0.5724 (2)	0.65802 (7)	0.0372 (3)
H10	0.3424 (7)	0.628 (2)	0.6850 (9)	0.047 (4)*
C11	0.35024 (5)	0.63067 (18)	0.58415 (7)	0.0337 (3)
H11	0.3201 (7)	0.728 (2)	0.5559 (9)	0.046 (4)*
C12	0.37979 (5)	0.54851 (16)	0.54796 (6)	0.0291 (3)
H12	0.3720 (6)	0.593 (2)	0.4963 (8)	0.031 (3)*
C13	0.32570 (5)	0.35885 (17)	0.37772 (6)	0.0306 (3)
C14	0.29848 (6)	0.51143 (19)	0.32611 (7)	0.0387 (3)
H14	0.3218 (6)	0.577 (2)	0.3046 (8)	0.039 (4)*
C15	0.24060 (7)	0.5620 (2)	0.30375 (8)	0.0486 (4)
H15	0.2227 (8)	0.669 (3)	0.2667 (10)	0.060 (5)*
C16	0.20979 (6)	0.4615 (2)	0.33326 (9)	0.0512 (4)
H16	0.1656 (8)	0.497 (3)	0.3175 (10)	0.062 (5)*
C17	0.23610 (6)	0.3093 (2)	0.38378 (9)	0.0443 (3)
H17	0.2145 (7)	0.234 (3)	0.4087 (10)	0.056 (5)*
C18	0.29390 (5)	0.25321 (18)	0.40601 (7)	0.0340 (3)
C19	0.31878 (6)	0.0783 (2)	0.45680 (9)	0.0425 (3)
H19A	0.3415 (12)	0.112 (4)	0.5138 (16)	0.110 (8)*
H19B	0.3482 (10)	0.005 (4)	0.4467 (13)	0.098 (7)*
H19C	0.2857 (10)	−0.014 (4)	0.4487 (13)	0.098 (7)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0322 (5)	0.0299 (5)	0.0291 (5)	−0.0016 (4)	0.0136 (4)	0.0013 (4)
N2	0.0344 (5)	0.0257 (5)	0.0387 (5)	−0.0015 (4)	0.0211 (4)	0.0020 (4)
N3	0.0407 (5)	0.0301 (5)	0.0301 (5)	−0.0013 (4)	0.0228 (4)	−0.0008 (4)
N4	0.0387 (5)	0.0320 (5)	0.0278 (5)	−0.0010 (4)	0.0183 (4)	0.0003 (4)
C1	0.0314 (5)	0.0228 (5)	0.0253 (5)	−0.0030 (4)	0.0137 (4)	0.0008 (4)
C2	0.0314 (6)	0.0288 (6)	0.0354 (6)	−0.0009 (4)	0.0157 (5)	0.0031 (5)
C3	0.0358 (6)	0.0213 (5)	0.0307 (6)	−0.0023 (4)	0.0196 (5)	0.0007 (4)
C4	0.0526 (8)	0.0377 (7)	0.0385 (7)	−0.0001 (6)	0.0329 (6)	−0.0021 (6)
C5	0.0356 (6)	0.0262 (5)	0.0239 (5)	−0.0015 (4)	0.0154 (4)	0.0008 (4)
C6	0.0323 (5)	0.0225 (5)	0.0261 (5)	−0.0012 (4)	0.0160 (4)	0.0010 (4)
C7	0.0308 (5)	0.0272 (5)	0.0231 (5)	−0.0043 (4)	0.0130 (4)	−0.0022 (4)
C8	0.0351 (6)	0.0337 (6)	0.0242 (5)	−0.0016 (5)	0.0129 (4)	0.0004 (4)
C9	0.0418 (6)	0.0436 (7)	0.0250 (5)	−0.0040 (5)	0.0177 (5)	−0.0004 (5)
C10	0.0423 (7)	0.0422 (7)	0.0337 (6)	−0.0018 (5)	0.0236 (5)	−0.0053 (5)
C11	0.0368 (6)	0.0332 (6)	0.0333 (6)	0.0011 (5)	0.0186 (5)	−0.0003 (5)
C12	0.0340 (6)	0.0290 (5)	0.0251 (5)	−0.0030 (4)	0.0148 (4)	−0.0002 (4)
C13	0.0338 (6)	0.0311 (6)	0.0234 (5)	−0.0003 (4)	0.0110 (4)	−0.0028 (4)
C14	0.0435 (7)	0.0380 (7)	0.0291 (6)	0.0029 (5)	0.0129 (5)	0.0030 (5)
C15	0.0474 (8)	0.0447 (8)	0.0405 (7)	0.0126 (6)	0.0106 (6)	0.0076 (6)
C16	0.0358 (7)	0.0515 (8)	0.0560 (9)	0.0066 (6)	0.0137 (6)	−0.0006 (7)
C17	0.0358 (7)	0.0452 (7)	0.0501 (8)	−0.0010 (6)	0.0192 (6)	−0.0023 (6)
C18	0.0327 (6)	0.0351 (6)	0.0319 (6)	−0.0017 (5)	0.0137 (5)	−0.0025 (5)
C19	0.0400 (7)	0.0402 (7)	0.0482 (8)	−0.0028 (6)	0.0218 (6)	0.0081 (6)

Geometric parameters (Å, º) top

N1—C1	1.3440 (14)	C9—C10	1.3861 (19)
N1—C2	1.3462 (16)	C9—H9	0.993 (16)
N2—C2	1.3235 (16)	C10—C11	1.3879 (17)
N2—C3	1.3412 (15)	C10—H10	0.991 (16)
N3—C3	1.3496 (15)	C11—C12	1.3919 (16)
N3—N4	1.3642 (14)	C11—H11	0.978 (16)
N3—C4	1.4510 (15)	C12—H12	0.987 (14)
N4—C5	1.3277 (14)	C13—C14	1.3998 (17)
C1—C6	1.4109 (15)	C13—C18	1.4004 (17)
C1—C7	1.4806 (15)	C14—C15	1.387 (2)
C2—H3	0.964 (14)	C14—H14	0.998 (15)
C3—C6	1.4111 (15)	C15—C16	1.379 (2)
C4—H4A	0.95 (2)	C15—H15	0.984 (19)
C4—H4B	0.967 (18)	C16—C17	1.384 (2)
C4—H4C	0.982 (19)	C16—H16	1.061 (17)
C5—C6	1.4363 (15)	C17—C18	1.3961 (18)
C5—C13	1.4820 (16)	C17—H17	1.043 (18)
C7—C12	1.3943 (16)	C18—C19	1.5053 (18)
C7—C8	1.4009 (15)	C19—H19A	1.01 (3)
C8—C9	1.3805 (17)	C19—H19B	1.01 (3)
C8—H8	0.977 (15)	C19—H19C	1.02 (3)

C1—N1—C2	118.79 (10)	C10—C9—H9	120.8 (9)
C2—N2—C3	111.54 (10)	C9—C10—C11	119.95 (11)
C3—N3—N4	111.12 (9)	C9—C10—H10	118.2 (9)
C3—N3—C4	128.11 (11)	C11—C10—H10	121.9 (9)
N4—N3—C4	120.76 (10)	C10—C11—C12	120.29 (12)
C5—N4—N3	107.33 (9)	C10—C11—H11	121.3 (9)
N1—C1—C6	118.80 (10)	C12—C11—H11	118.4 (9)
N1—C1—C7	115.52 (9)	C11—C12—C7	120.13 (10)
C6—C1—C7	125.67 (10)	C11—C12—H12	120.5 (8)
N2—C2—N1	128.65 (11)	C7—C12—H12	119.3 (8)
N2—C2—H3	116.0 (8)	C14—C13—C18	119.76 (11)
N1—C2—H3	115.4 (8)	C14—C13—C5	118.51 (11)
N2—C3—N3	125.83 (10)	C18—C13—C5	121.71 (10)
N2—C3—C6	126.73 (10)	C15—C14—C13	120.78 (13)
N3—C3—C6	107.40 (10)	C15—C14—H14	122.0 (8)
N3—C4—H4A	109.8 (12)	C13—C14—H14	117.2 (8)
N3—C4—H4B	109.2 (10)	C16—C15—C14	119.47 (13)
H4A—C4—H4B	108.1 (16)	C16—C15—H15	122.0 (11)
N3—C4—H4C	108.7 (10)	C14—C15—H15	118.5 (11)
H4A—C4—H4C	110.8 (16)	C15—C16—C17	120.23 (13)
H4B—C4—H4C	110.1 (15)	C15—C16—H16	121.3 (10)
N4—C5—C6	109.96 (10)	C17—C16—H16	118.5 (10)
N4—C5—C13	118.42 (10)	C16—C17—C18	121.40 (14)
C6—C5—C13	131.61 (10)	C16—C17—H17	122.0 (10)
C1—C6—C3	115.28 (10)	C18—C17—H17	116.5 (9)
C1—C6—C5	140.57 (10)	C17—C18—C13	118.31 (12)
C3—C6—C5	104.15 (9)	C17—C18—C19	119.00 (12)
C12—C7—C8	118.78 (10)	C13—C18—C19	122.66 (11)
C12—C7—C1	122.23 (10)	C18—C19—H19A	112.7 (16)
C8—C7—C1	118.83 (10)	C18—C19—H19B	113.5 (14)
C9—C8—C7	120.92 (11)	H19A—C19—H19B	104.1 (19)
C9—C8—H8	120.2 (8)	C18—C19—H19C	110.2 (13)
C7—C8—H8	118.8 (8)	H19A—C19—H19C	108.4 (19)
C8—C9—C10	119.92 (11)	H19B—C19—H19C	108 (2)
C8—C9—H9	119.2 (9)

C3—N3—N4—C5	0.49 (13)	C6—C1—C7—C12	−34.01 (16)
C4—N3—N4—C5	−179.90 (10)	N1—C1—C7—C8	−30.76 (15)
C2—N1—C1—C6	2.10 (15)	C6—C1—C7—C8	150.72 (11)
C2—N1—C1—C7	−176.53 (10)	C12—C7—C8—C9	−0.82 (17)
C3—N2—C2—N1	−2.75 (17)	C1—C7—C8—C9	174.62 (11)
C1—N1—C2—N2	1.98 (18)	C7—C8—C9—C10	0.21 (19)
C2—N2—C3—N3	−177.90 (10)	C8—C9—C10—C11	0.56 (19)
C2—N2—C3—C6	−0.49 (16)	C9—C10—C11—C12	−0.70 (19)
N4—N3—C3—N2	176.18 (10)	C10—C11—C12—C7	0.09 (18)
C4—N3—C3—N2	−3.39 (19)	C8—C7—C12—C11	0.66 (17)
N4—N3—C3—C6	−1.64 (12)	C1—C7—C12—C11	−174.61 (10)
C4—N3—C3—C6	178.79 (11)	N4—C5—C13—C14	−56.95 (15)
N3—N4—C5—C6	0.86 (12)	C6—C5—C13—C14	123.35 (13)
N3—N4—C5—C13	−178.91 (9)	N4—C5—C13—C18	121.40 (12)
N1—C1—C6—C3	−4.64 (15)	C6—C5—C13—C18	−58.30 (17)
C7—C1—C6—C3	173.83 (10)	C18—C13—C14—C15	1.29 (19)
N1—C1—C6—C5	175.06 (13)	C5—C13—C14—C15	179.68 (12)
C7—C1—C6—C5	−6.5 (2)	C13—C14—C15—C16	0.5 (2)
N2—C3—C6—C1	4.03 (16)	C14—C15—C16—C17	−1.1 (2)
N3—C3—C6—C1	−178.17 (9)	C15—C16—C17—C18	−0.1 (2)
N2—C3—C6—C5	−175.77 (10)	C16—C17—C18—C13	1.9 (2)
N3—C3—C6—C5	2.02 (11)	C16—C17—C18—C19	−175.90 (13)
N4—C5—C6—C1	178.48 (13)	C14—C13—C18—C17	−2.47 (18)
C13—C5—C6—C1	−1.8 (2)	C5—C13—C18—C17	179.20 (11)
N4—C5—C6—C3	−1.79 (12)	C14—C13—C18—C19	175.27 (12)
C13—C5—C6—C3	177.93 (11)	C5—C13—C18—C19	−3.06 (18)
N1—C1—C7—C12	144.51 (11)

Acknowledgements

Tulane University is gratefully acknowledged for support of the Tulane Crystallography Laboratory.

Funding information

Funding for this research was provided by: NSF–MRI (grant No. 1228232), for the purchase of the diffractometer.

References

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