3,6-Dimethyl-1-phenyl-4-(2-thien­yl)-8-(2-thienylmethyl­ene)-5,6,7,8-tetra­hydro-1H-pyrazolo[3,4-b][1,6]naphthyridine

Juhua Peng; Zhengguo Han; Ning Ma; Shujiang Tu

doi:10.1107/S1600536809014810

. 2009 Apr 25;65(Pt 5):o1109–o1110. doi: 10.1107/S1600536809014810

3,6-Dimethyl-1-phenyl-4-(2-thienyl)-8-(2-thienylmethylene)-5,6,7,8-tetrahydro-1H-pyrazolo[3,4-b][1,6]naphthyridine

Juhua Peng ^a, Zhengguo Han ^b, Ning Ma ^b, Shujiang Tu ^b,^*

PMCID: PMC2977787 PMID: 21583923

Abstract

In the molecule of the title compound, C₂₆H₂₂N₄S₂, the pyrazole ring is oriented at a dihedral angle of 0.85 (3)° with respect to the adjacent naphthyridine ring, while the other ring of naphthyridine adopts an envelope conformation. The dihedral angle between phenyl and pyrazole rings is 87.65 (3)°. In the crystal structure, weak intermolecular C—H⋯N interactions link the molecules into chains. The π–π contacts between the naphthyridine rings and the naphthyridine and thiophene rings [centroid–centroid distances = 3.766 (3) and 3.878 (3) Å] may further stabilize the structure. A weak C—H⋯π interaction is also present.

Related literature

For the biological activity of naphthyridines, see: Abou et al. (2001 ▶); Aleem et al. (2002 ▶); Blagg et al. (2003 ▶); Ohta et al. (2004 ▶). For the biological properties of pyrazolopyridine derivatives, see: Lynck et al. (1988 ▶); Fucini et al. (2008 ▶); Warshakoon et al. (2006 ▶). They are also active against gram positive and gram negative bacteria, see: El-Dean et al. (1991 ▶) and inhibit cholesterol formation, see: Fujikawa et al. (1989 ▶, 1990 ▶). For bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₂₆H₂₂N₄S₂
M _r = 454.60
Triclinic,
a = 10.7187 (16) Å
b = 10.9704 (19) Å
c = 11.153 (2) Å
α = 109.785 (2)°
β = 102.364 (1)°
γ = 104.201 (1)°
V = 1131.0 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.26 mm⁻¹
T = 298 K
0.18 × 0.17 × 0.16 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.955, T _max = 0.960
5846 measured reflections
3918 independent reflections
2322 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.057
wR(F ²) = 0.176
S = 1.00
3918 reflections
291 parameters
H-atom parameters constrained
Δρ_max = 0.31 e Å⁻³
Δρ_min = −0.43 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1998 ▶); 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, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809014810/hk2672sup1.cif

e-65-o1109-sup1.cif^{(23.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809014810/hk2672Isup2.hkl

e-65-o1109-Isup2.hkl^{(192KB, 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
C26—H26⋯N2ⁱ	0.93	2.57	3.445 (3)	157
C20—H20⋯Cg6ⁱⁱ	0.93	2.93	3.680 (3)	139

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Symmetry codes: (i) Inline graphic ; (ii) . Cg6 is the centroid of the S1/C23–C26 ring.

Acknowledgments

The authors thank the National Natural Science Foundation of China (grant No. 20672090), the Natural Science Foundation of Jiangsu Province (grant No. BK2006033) and the Six Kinds of Professional Elite Foundation of Jiangsu Province (grant No. 06-A-039) for financial support.

supplementary crystallographic information

Comment

Naphthyridines have received considerable attention over the past years because of their wide range of biological activities including antitumor (Abou et al., 2001; Aleem et al., 2002), anti-inflammatory (Blagg et al., 2003) and antifungal (Ohta et al., 2004) activities. Pyrazolopyridine derivatives are important heterocyclic compounds, which exhibit a diverse range of biological properties such as new inhibitors of xanthine oxidases (Lynck et al., 1988), as Polo-like kinase 1 inhibitors (Fucini et al., 2008) and HIF-1alpha prolyl hydroxylase inhibitors (Warshakoon et al., 2006). They also have proven to be active against gram positive and gram negative bacterias (El-Dean et al., 1991) and also as compounds for the inhibition of cholesterol formation (Fujikawa et al., 1989, 1990). We report herein the crystal structure of the title compound, containing the skeletons of naphthyridine and pyrazolopyridine.

In the molecule of the title compound (Fig. 1), the bond lengths (Allen et al., 1987) and angles are within normal ranges. Rings A (N1/N2/C1-C3), B (N3/C2-C4/C6/C7), D (C10-C15), E (S2/C17-C20) and F (S1/C23-C26) are, of course, planar, and they are oriented at dihedral angles of A/B = 0.85 (3), A/D = 87.65 (3) and B/E = 18.10 (4) °. Ring C (N4/C5-C9) adopts envelope conformation, with atom N4 displaced by 0.660 (3) Å from the plane of the other ring atoms.

In the crystal structure, weak intermolecular C-H···N interactions (Table 1) link the molecules into chains (Fig. 2), in which they may be effective in the stabilization of the structure. The π–π contacts between the naphthyridine rings and the naphthyridine and thiophene rings, Cg2—Cg2ⁱ and Cg2—Cg6ⁱⁱ [symmetry codes: (i) 1 - x, 1 - y, 1 - z, (ii) -x, 1 - y, 1 - z, where Cg2 and Cg6 are centroids of the rings B (N3/C2-C4/C6/C7) and F (S1/C23-C26), respectively] may further stabilize the structure, with centroid-centroid distances of 3.766 (3) and 3.878 (3) Å, respectively. There also exists a weak C-H···π interaction (Table 1).

Experimental

The title compound was prepared by the reaction of of 1-methyl-3,5-bis(thiophen -2-ylmethylene)piperidin-4-one (1 mmol) and 3-methyl-1-phenyl-1H-pyrazol -5- amine (1 mmol) in glycol (2 ml).