7-(4-Methoxy­phen­yl)-5-methyl-9-phenyl-7H-pyrrolo[2′,3′:4,5]pyrimido[1,6-d]tetrazole

Mukesh M Jotani; Rina D Shah; Jerry P Jasinski

doi:10.1107/S1600536809053653

. 2009 Dec 19;66(Pt 1):o212–o213. doi: 10.1107/S1600536809053653

7-(4-Methoxyphenyl)-5-methyl-9-phenyl-7H-pyrrolo[2′,3′:4,5]pyrimido[1,6-d]tetrazole

Mukesh M Jotani ^a, Rina D Shah ^b, Jerry P Jasinski ^c,^*

PMCID: PMC2980237 PMID: 21580097

Abstract

The title compound, C₂₀H₁₆N₆O, is composed of a tetrazolo ring and a 4-methoxyphenyl and a benzene-substituted pyrrole ring at the 7 and 9 positions fused to a pyrimidine ring in a nearly planar fashion [maximum deviation of 0.018 (1) Å for the fused ring system]. A methyl group at the 5 position is also in the plane of the hetero cyclic system. The dihedral angle between the mean planes of the benzene and 4-methoxyphenyl rings is 40.4 (2)°. The dihedral angles between the mean planes of the pyrimidine and the benzene and 4-methoxyphenyl rings are 15.6 (5)° and 52.6 (7)°, respectively. A weak intramolecular C—H⋯N hydrogen bond interaction, which forms an S(7) graph-set motif, helps to establish the relative conformations of the tetrazolo and benzene rings. In the crystal, weak intermolecular C—H⋯O, C—H⋯π and π–π stacking interactions [centroid–centroid distances = 3.5270 (16), 3.5113 (16), 3.7275 (17) and 3.7866 (17) Å] link the molecules into a two-dimensional array obliquely parallel to (101) and propagating along the b axis.

Related literature

For the biological activity of fused tetrazolopyrimidines, see: Wilkinson (1992 ▶); Omer et al. (1991 ▶); Schram et al. (1975 ▶). Fused pyrimidines with a halogen at the 2- or 4- position seem to be more labile towards a nucleophilic substitution reaction with reagents such as piperadine, piperazine, morpholine, hydrazine and azides, forming potent bi- and triheterocycles, see: Dave & Shah (2000 ▶, 2002 ▶); Peinador et al. (1992 ▶); Schneller & Clough (1992 ▶); Shishoo & Jain (1992 ▶). For the importance of the reduction of tetrazolopyrimidines via azidolysis in the development of synthetically important 4-aminopyrimidines, see: Shishoo & Jain (1992 ▶); Hand & Backer (1984 ▶). For nucleophilic substitution reactions in pyrrolo[2,3-e] pyrimidines, see: Dave & Shah (2002 ▶); Ali & Swealan (1992 ▶). For related structures, see: Jotani & Baldaniya (2007 ▶, 2008 ▶); Hou et al. (2009 ▶); Baldaniya & Jotani (2008 ▶); Malone et al. (1997 ▶). For the synthesis, see: Shah (2009 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For tetrazolo ring formation, see: Bourgurgnon et al. (1975 ▶); Robba et al. (1975 ▶).

Experimental

Crystal data

C₂₀H₁₆N₆O
M _r = 356.39
Monoclinic,
a = 13.738 (2) Å
b = 7.032 (3) Å
c = 19.4350 (3) Å
β = 110.217 (2)°
V = 1761.9 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.47 × 0.35 × 0.2 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.96, T _max = 0.98
42323 measured reflections
5137 independent reflections
3694 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.129
S = 1.04
5137 reflections
247 parameters
H-atom parameters constrained
Δρ_max = 0.29 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2 and SAINT (Bruker, 2004 ▶); data reduction: SAINT and XPREP (Bruker, 2004 ▶); program(s) used to solve structure: SIR2004 (Burla et al., 2003 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-32 and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809053653/gw2072sup1.cif

e-66-0o212-sup1.cif^{(21.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809053653/gw2072Isup2.hkl

e-66-0o212-Isup2.hkl^{(246.5KB, 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
C13—H13⋯N6	0.95	2.38	3.2159 (18)	146
C12—H12⋯O1ⁱ	0.95	2.57	3.3902 (17)	144
C7—H7B⋯Cg4ⁱⁱ	0.96	2.90	3.620 (2)	132
C7—H7C⋯Cg4ⁱⁱⁱ	0.96	2.69	3.554 (2)	150

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) . Cg4 is the centroid of the C8–C13. ring.

Acknowledgments

The authors thank Department of Science and Technology (DST) and the SAIF, IIT Madras, Chennai, India, for the intensity data collection.

supplementary crystallographic information

Comment

Fused tetrazolopyrimidines are important to the activities of a variety of biological substances (Willkinson, 1992; Omer et al., 1991; Schram et al., 1975). Moreover, fused pyrimidines having a halogen at the 2- or 4- position seem to be more labile towards a nucleophilic substitution reaction with reagents such as piperadine, piperazine, morpholine, hydrazine and azides to form potent bi and triheterocycles (Dave & Shah, 2002; Peinador et al., 1992; Schneller & Clough, 1992; Shishoo & Jain, 1992). The reduction of tetrazolopyrimidines via azidolysis studies have been shown to be to attractive to development of synthetically important 4-aminopyrimidines (Shishoo & Jain, 1992; Hand & Backer, 1984). The treatment of sodium azide with 4-chloropyrrolo[2,3-e] pyrimidine can result the formation of either an azido group or tetrazole ring upon a fused pyrimidine ring. Such nucleophilic substitution reactions have rarely been attempted in pyrrolo[2,3-e] pyrimidines (Dave & Shah, 2002; Ali & Swealan, 1992). In view of the importance of these molecules, a crystal structure of the title compound, C₂₀H₁₆N₆O, (I) has been determined.

The title compound, C₂₀H₁₆N₆O, (I), is composed of a tetrazolo ring and a 4-methoxyphenyl and benzene substituted pyrrole ring at the 7 and 9 position fused to a pyrimidine ring in a nearly planar fashion (Fig. 1). The r.m.s.deviation of atoms of the fused ring from the mean plane through the heterotricyclic system is 0.0085 Å, with a maximum deviation of -0.018 (1) and 0.013 (1) Å for atoms C2 and C3 respectively. Bond lengths and angles for the fused pyrrole and tetrazole rings in (I) are normal and similar to that observed for a related structure. The dihedral angles between the mean planes of fused pyrimidine and tetrazole rings with that of the pyrrole ring are 1.26 (6) ° and 1.13 (7)°, respectively. A methyl group at the 5 position is also in the plane of the pyrimidine ring. The dihedral angle between the mean planes of the benzene and 4-methoxyphenyl rings is 40.4 (2)°. The angles between the mean planes of the pyrimidine and the benzene and 4-methoxyphenyl rings are 15.6 (5)° and 52.6 (7)°, respectively. A weak intramolecular C13–H13···N6 hydrogen bond interaction, which forms an S(7) graph set, helps stabilize the separation angle between the tetrazolo and benzene rings. Weak intermolecular C12–H12···O1 (Fig. 2), C–H···π-ring (C7–H7B(H7C)···Cg4 [= 3.620 (2) (3.554 (2) Å; 1 - x, 1 - y, 1 - z (1 - x, 2 - y, 1 - z); where Cg4 = C8–C13 ring centroid; Table 1] and π–π [Cg1···Cg2; = 3.5270 (16)Å & 3.5113 (16) Å,1 - x, 1 - y, 1 - x & 1 - x, 2 - y, 1 - z; Cg2···Cg3; = 3.7275 (17) Å, 1 - x, 2 - y, 1 - z; Cg3···Cg1; = 3.7866 (17) Å, 1 - x, 1 - y, 1 - z; where Cg1 = N1/C1–C4, Cg2 = N3–N6/C6, Cg3 = N2/C1–C5] stacking interactions (Fig. 3) help to link the molecules into a 2-D array obliquely parallel to (101) and propagating along the b axis.

Experimental

The title compound was synthesized according to method of Shah (2009). A mixture of sodium azide (0.011 mole), ammonium chloride (0.011 mole) and 2-methyl-5-phenyl-7-(4-methoxyphenyl)-4-chloro-7H-pyrrolo[2,3-d]pyrimidine (0.01 mole) in DMSO (20 ml) was stirred for for 2 h at 363 K to obtain the title compound (I). Colorless platlike single crystals, suitable for X-ray diffraction were grown from a solution of 1,4-dioxane.