5-Methyl-3-(3-methyl­phen­yl)-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine

Jasmin Preis; Dieter Schollmeyer; Heiner Detert

doi:10.1107/S1600536811010683

. 2011 Mar 26;67(Pt 4):o987. doi: 10.1107/S1600536811010683

5-Methyl-3-(3-methylphenyl)-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine

Jasmin Preis ^a, Dieter Schollmeyer ^a, Heiner Detert ^a,^*

PMCID: PMC3099827 PMID: 21754244

Abstract

The title compound, C₁₉H₁₆N₄, is one of the few known 3,7-diaryl-1,2,4-triazolo[4,3-c]pyrimidines. The triazolopyrimidine unit is essentially planar (r.m.s. deviation = 0.048 Å). The phenyl ring and the heterocyclic core subtend a dihedral angle of only 15.09 (6)°, whereas the m-tolyl ring is twisted by 71.80 (6)° out of the plane of the triazole ring. Two C—H⋯N hydrogen bonds and π–π stacking interactions [centroid–centroid distance = 3.7045 (8) Å] stabilize the crystal packing.

Related literature

For the synthesis of higher conjugated and annulated heterocyclic π-systems, see: Detert & Schollmeyer (1999 ▶); Sugiono & Detert (2001 ▶). The acylation of tetrazoles with chloroazines and thermal ring transformation leads to triazolo annulated azines, see: Huisgen, Sauer & Seidel (1960 ▶); Huisgen, Sturm & Markgraf (1960 ▶); Huisgen et al. (1961 ▶); Glang et al. (2008 ▶). Whereas a broad variety of triazolopyrimidines are known, only two further [1,2,4]triazolo[4,3-c]pyrimidines with a 3,7-diaryl substitution have been reported so far, see: Seada et al. (1992 ▶).

Experimental

Crystal data

C₁₉H₁₆N₄
M _r = 300.36
Triclinic,
a = 6.4270 (4) Å
b = 11.1706 (6) Å
c = 11.3672 (7) Å
α = 79.963 (5)°
β = 74.894 (5)°
γ = 81.877 (5)°
V = 771.88 (8) Å³
Z = 2
Cu Kα radiation
μ = 0.63 mm⁻¹
T = 193 K
0.45 × 0.40 × 0.25 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
3207 measured reflections
2924 independent reflections
2573 reflections with I > 2σ(I)
R _int = 0.088
3 standard reflections every 60 min intensity decay: 2%

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.119
S = 1.03
2924 reflections
211 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 Software; data reduction: CORINC (Dräger & Gattow, 1971 ▶); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811010683/bt5497sup1.cif

e-67-0o987-sup1.cif^{(19.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811010683/bt5497Isup2.hkl

e-67-0o987-Isup2.hkl^{(143.5KB, 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
C6—H6⋯N8ⁱ	0.95	2.53	3.4597 (17)	166
C23—H23⋯N8ⁱ	0.95	2.61	3.5374 (19)	167

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

The title compound was synthesized as part of a larger project focusing on the synthesis of higher conjugated and annulated heterocyclic π-systems see Detert & Schollmeyer (1999), Sugiono & Detert (2001). The acylation of tetrazoles followed by thermal ring transformation is a highly efficient route for the synthesis of 1,3,4-oxadiazoles and triazoles (Huisgen, Sauer & Seidel 1960; Huisgen, Sturm & Markgraf, 1960) and can also be applied to 2-chloroazines to yield triazolo-annulated azines. In the crystals of the title compound, the phenyl ring is only slightly turned out of the plane of the heterocyclic core [dihedral angle of 15.09 (6)°], the angle between the mean planes of the core and the m-tolyl ring amounts to 71.80 (6)°. Two molecules of the title compound form a dimer connected via hydrogen bonds C6—H6···N8 (2.53 Å) and C23—H23···N8 (2.61 Å). In the crystal, the dimers are connected viaπ-π-interactions between the rings with a distance of the triazoles (C1—N2, C7—N9) of 3.5404 (8) Å and of the pyrimidines (N2—C7) of 3.7045 (8) Å.

Experimental

The title compound was prepared by adding 2,4,6-collidine (0.54 g, 4.5 mmol) to a solution of 4-chloro-2-methyl-6-phenylpyrimidine (0.61 g, 3 mmol) and 5-(3-methyl- phenyl)tetrazole in xylenes (60 ml) and heating until gas was evolved (363 K). Stirring and heating was continued for 6 h, the solvent removed in vacuo and the residue purified by chromatography (SiO₂ /toluene/ethyl acetate = 1 / 1, R_f = 0.28). The title compound was isolated as a yellowish powder with m.p. = 412–413 K. Crystals were obtained by slow evaporation of a solution of the title compound in chloroform/hexanes. All spectrocopic data were in accordance with the assumed structure, but an unique proton-proton coupling over 6 bonds from the pyrimidine-H across the heterocycle to the methyl group was observed.