The crystal structure of 1,5-dibenzyl-1H-pyrazolo­[3,4-d]pyrimidine-4(5H)-thione

Mohammed El Fal; Youssef Ramli; El Mokhtar Essassi; Mohamed Saadi; Lahcen El Ammari

doi:10.1107/S205698901402828X

. 2015 Jan 10;71(Pt 2):o95–o96. doi: 10.1107/S205698901402828X

The crystal structure of 1,5-dibenzyl-1H-pyrazolo[3,4-d]pyrimidine-4(5H)-thione

Mohammed El Fal ^a, Youssef Ramli ^b, El Mokhtar Essassi ^a,^*, Mohamed Saadi ^c, Lahcen El Ammari ^c

PMCID: PMC4384557 PMID: 25878890

Abstract

In the title compound, C₁₉H₁₆N₄S, the pyrazolo[3,4-d]pyrimidine ring is close to being planar, with the greatest deviation from the mean plane being 0.023 (2) Å for the C atom bearing the thione S atom. The two phenyl rings are nearly perpendicular to the fused ring system [dihedral angles = 71.4 (2) and 78.1 (2)°], but are oriented in opposite directions; the dihedral angle between the phenyl rings is 32.22 (16)°. In the crystal, linear supramolecular chains along [101] are sustained by C—H⋯S interactions.

Keywords: crystal structure; pyrazolo[3,4-d]pyrimidine; thione; C—H⋯S interactions

Related literature

For pharmacological and biochemical properties of pyrazolo[1,5-a]pyrimidine, see: Orlikova et al. (2014 ▸); Yuan et al. (2013 ▸); Rashad et al. (2011 ▸). For related structures, see: El Fal et al. (2013 ▸, 2014 ▸); Alsubari et al. (2011 ▸); Ramli et al. (2012 ▸).

Experimental

Crystal data

C₁₉H₁₆N₄S
M _r = 332.42
Monoclinic,
a = 4.4953 (12) Å
b = 29.140 (8) Å
c = 6.3889 (16) Å
β = 97.860 (9)°
V = 829.0 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.20 mm⁻¹
T = 296 K
0.37 × 0.34 × 0.29 mm

Data collection

Bruker X8 APEX diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▸) T _min = 0.589, T _max = 0.746
9214 measured reflections
3582 independent reflections
2406 reflections with I > 2σ(I)
R _int = 0.040

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.084
S = 0.97
3582 reflections
217 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.12 e Å⁻³
Absolute structure: Flack & Bernardinelli (2000 ▸), 1730 Friedel pairs
Absolute structure parameter: −0.11 (7)

Data collection: APEX2 (Bruker, 2009 ▸); cell refinement: SAINT-Plus (Bruker, 2009 ▸); data reduction: SAINT-Plus; 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 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S205698901402828X/tk5354sup1.cif

e-71-00o95-sup1.cif^{(23.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S205698901402828X/tk5354Isup2.hkl

e-71-00o95-Isup2.hkl^{(175.6KB, hkl)}

Click here for additional data file.^{(6.4KB, cml)}

Supporting information file. DOI: 10.1107/S205698901402828X/tk5354Isup3.cml

Click here for additional data file.^{(1.2MB, tif)}

. DOI: 10.1107/S205698901402828X/tk5354fig1.tif

Molecular structure of the title compound with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small circles.

CCDC reference: 1041681

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
C5H5S1ⁱ	0.93	2.87	3.784(3)	167

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements and the University Mohammed V, Rabat, Morocco, for financial support.

supplementary crystallographic information

S1. Structural commentary

Pyrazolo[3,4-d] pyrimidine-4-thione are intermediate sub-units useful for the development of molecules of pharmaceutical interest. They have found applications in various therapeutic areas, including anti-inflammatory, anti-tumour and anti-cancer (Orlikova et al., 2014; Yuan et al., 2013; Rashad et al., 2011). 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; El Fal et al., 2014; Alsubari et al., 2011; Ramli et al., 2012).

The molecule of the title compound is build up from two fused five- and six-membered heterocycles linked to two phenyl rings via two –CH₂– groups as shown in Fig. 1. The pyrazolo[3,4-d]pyrimidine system is virtually planar with the largest deviation from the mean plane being -0.023 (2) Å at C1 and makes dihedral angles of 71.4 (2)° and 78.1 (2)° with the mean plane through the first (C7 to C12) and the second (C14 to C19) phenyl rings, respectively. As a matter of fact, the two phenyl rings are oriented in opposite direction to the plane of the fused rings. No classic hydrogen bonds are observed in the present structure.

S2. Synthesis and crystallization

3.32 g (10 mmol) of 1,5-dibenzyl-1H, 4H, 5H-pyrazolo [3,4-d] pyrimidin-4-one is refluxed in pyridine (30 ml) with 5.55 g (25 mmol) of phosphorus pentasulfide for 4 h. Then the solvent was evaporated under reduced pressure. The precipitate that formed was washed with hot water to remove residual dimerized P₂S₅ until colourless filtrate was noted. The solid was re-crystallized from ethanol to afford the title compound as yellow crystals (yield: 85%; m.p. = 563 K).

S3. Refinement

The H atoms were located in a difference map and treated as riding with C—H = 0.93 Å (aromatic) and C—H = 0.97 Å (methylene). All hydrogen with U_iso(H) = 1.2 U_eq (aromatic and methylene). Two reflections, i.e. 0 -2 0 and 0 2 0, were omitted fro the final refinement owing to poor agreement.