6-(4-Fluoro­pheneth­yl)-7-imino-3-phenyl-2,3,6,7-tetra­hydro-1,3-thia­zolo[4,5-d]pyrimidine-2-thione

Ying Liang; Hong-Wu He; Zi-Wen Yang

doi:10.1107/S1600536809047576

. 2009 Nov 14;65(Pt 12):o3098. doi: 10.1107/S1600536809047576

6-(4-Fluorophenethyl)-7-imino-3-phenyl-2,3,6,7-tetrahydro-1,3-thiazolo[4,5-d]pyrimidine-2-thione

Ying Liang ^a,^b,^*, Hong-Wu He ^b, Zi-Wen Yang ^a

PMCID: PMC2971921 PMID: 21578826

Abstract

In the title compound, C₁₉H₁₅FN₄S₂, the mean plane of the thiazolopyrimidine makes a dihedral angle of 77.6 (1)° with the attached phenyl ring. The crystal packing is stabilized by intermolecular C—H⋯N hydrogen bonds and weak C—H—π stacking interactions.

Related literature

For the biological activity of thiazolo[4,5-d]pyrimidine derivatives, see: Balkan et al. (2002 ▶); Bekhit et al. (2003 ▶); Danel et al. (1998 ▶); Fahmy et al. (2003 ▶). For the synthesis of thiazolo [4,5-d]pyrimidines via tandem aza-Wittig and cyclization reactions of iminophosphorane and alkylamines, see: Liang et al. (2007 ▶). For C—H⋯π interactions, see: Janiak (2000 ▶). For bond-length data, see: Allen et al. (1987 ▶). graphic file with name e-65-o3098-scheme1.jpg

Experimental

Crystal data

C₁₉H₁₅FN₄S₂
M _r = 382.47
Monoclinic,
a = 8.6449 (13) Å
b = 12.3780 (19) Å
c = 16.546 (3) Å
β = 91.531 (3)°
V = 1769.9 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.32 mm⁻¹
T = 298 K
0.30 × 0.20 × 0.20 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ▶) T _min = 0.910, T _max = 0.939
13207 measured reflections
4047 independent reflections
3442 reflections with I > 2σ(I)
R _int = 0.023

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.119
S = 1.05
4047 reflections
238 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809047576/jh2113sup1.cif

e-65-o3098-sup1.cif^{(20.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809047576/jh2113Isup2.hkl

e-65-o3098-Isup2.hkl^{(198.4KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15⋯N3ⁱ	0.93	2.61	3.486 (3)	156
C19—H19⋯Cg3ⁱⁱ	0.93	2.74	3.637 (2)	161

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Symmetry codes: (i) Inline graphic ; (ii) . Cg3 is the centroid of the C1–C6 ring.

Acknowledgments

We gratefully acknowledge the financial support of this work by the National Basic Research Program of China (2003CB114400) and the National Natural Science Foundation of China (No. 20372023).

supplementary crystallographic information

Comment

Thiazolo[4,5-d]pyrimidine derivatives, which can be considered as thia-analogues of the natural purine bases such as adenine and guanine, have acquired a growing importance as anticancer agents (Fahmy et al., 2003), antiviral agents used in the treatment of human cytomegalovirus (Bekhit et al., 2003), antitumour agents (Balkan et al.,2002) and antibacterial agents (Danel et al., 1998).

An important synthetic route of our previous reports for thiazolo [4,5-d]pyrimidines is the tandem aza-Wittig and cyclization reaction of iminophosphorane and alkylamines (Liang et al., 2007). Recently, we have developed a new cyclization process to synthesize novel thiazolo[4,5-d]pyrimidine derivatives. In this paper, we report the structure of the title compound, (I)(Fig. 1).

In the molecule, all bond lengths and angles are normal (Allen et al., 1987). The mean plane of the thiazolopyrimidine fragment makes dihedral angle of 77.58 (10)° with the attached phenyl ring fragment. In the crystal structure, intermolecular C—H···N hydrogen-bonding interactions stabilize the structure (Table 1). In addition, short intermolecular distances between the centroids of the C1···C6 ring, Cg3, and C19···H19A [C19—H19···Cg3ⁱ = 2.740 (3) Å; symmetry code: (i) 1 - x, 1 - y, -z] indicate the existence of C—H-π stacking interactions (Janiak, 2000), which stabilize the crystal packing (Fig. 2) together with hydrogen-bonding interactions.

Experimental

To a suspension of 5-cyano-4-ethoxymethyleneamino-3-phenyl-3H-thiazolin- 2-thione (0.87 g 5 mmol) in 15 mL dry acetonitrile was added all at once 0.5 g (3.6 mmol) 4-fluorophenylethylamine. After standing at room temperature for 1.5 h, then the solution concentrated under vacuum and the residue was recrystallized from dichloromethane to give the title compound (yield 72.8%). Colourless crystals of (I) suitable for X-ray structure analysis were grown from the mixture of dichloromethane and ethanol (v/v, 1:3).