Ethyl 6-methyl-8-phenyl-1,2,4-triazolo[1,5-a]pyridine-7-carboxyl­ate

Li, Y.; Sun, C.; Zhang, R.

doi:10.1107/S1600536813031152

organic compounds

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Volume 69| Part 12| December 2013| Page o1812

doi:10.1107/S1600536813031152

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Ethyl 6-methyl-8-phenyl-1,2,4-triazolo[1,5-a]pyridine-7-carboxylate

Yang Li,^a ^* Chen Sun ^a and Ran Zhang ^a

^aSchool of Chemical Engineering, Taishan Medical University, Taian 271016, People's Republic of China
^*Correspondence e-mail: chemyangli@gmail.com

(Received 29 October 2013; accepted 13 November 2013; online 23 November 2013)

In title compound, C₁₆H₁₅N₃O₂, the 1,2,4-triazolo[1,5-a]pyridine ring system is almost planar (r.m.s. deviation = 0.0068 Å) and forms a dihedral angle of 61.4 (3)° with the phenyl ring. In the structure, centrosymmetrically related molecules are linked into dimers by pairs of C—H⋯N hydrogen bonds.

CCDC reference: 971651

Related literature

For application of [1,2,4]triazolo[1,5-a]pyridine derivatives, see: Luo & Hu (2006 ); Liu & Hu (2002 ). For the synthesis of [1,2,4]triazolo[1,5-a]pyridine derivatives, see: Jones & Sliskovic (1983 ); Wang et al. (2003 ); Ge et al. (2009 ); Jia et al. (2010 ). For standard bond lengths, see: Allen et al. (1987 ).

Experimental

Crystal data

C₁₆H₁₅N₃O₂
M_r = 281.31
Monoclinic, P 2₁ /n
a = 13.401 (3) Å
b = 7.4825 (19) Å
c = 15.068 (4) Å
β = 98.986 (4)°
V = 1492.4 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 K
0.23 × 0.19 × 0.15 mm

Data collection

Brucker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1999 ) T_min = 0.981, T_max = 0.987
7312 measured reflections
2611 independent reflections
1920 reflections with I > 2σ(I)
R_int = 0.086

Refinement

R[F² > 2σ(F²)] = 0.049
wR(F²) = 0.152
S = 1.05
2611 reflections
192 parameters
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6⋯N2ⁱ	0.93	2.49	3.332 (3)	151
Symmetry code: (i) -x, -y+2, -z+1.

Data collection: SMART (Bruker, 1998 ); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); 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 (Sheldrick, 2008).

Supporting information

CCDC reference: 971651

Crystal structure: contains datablocks 120713d, I. DOI: 10.1107/S1600536813031152/rz5092sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536813031152/rz5092Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536813031152/rz5092Isup3.cml

checkCIF report

Comment top

[1,2,4]Triazolo[1,5-a]pyridine derivatives are important heterocyclic compounds which exhibit antifungal, anticancer and anti-inflammatory activities (Luo & Hu, 2006; Liu & Hu, 2002). Despite possessing outstanding biological activities, only a few [1,2,4]triazolo[1,5-a]pyridines are known. Some commonly used synthetic methods are the annulation of the 1,2,4-triazole ring starting with amino substituted pyridines by a multistep procedure (Jones & Sliskovic, 1983). Previously, imidazo[1,5-a]pyridines, pyrazolo[1,5-a]pyridines, imidazo[1,2-a]pyridines and indolizines had been synthesized by a novel tandem reaction in our group (Wang et al., 2003; Ge et al., 2009; Jia et al., 2010). As an extension of this work, the synthesis of [1,2,4]triazolo[1,5-a]pyridine heterocycles through this procedure has been undertaken. We present here the crystal structure of one of such compounds, ethyl 8-phenyl-6-methyl-[1,2,4]triazolo[1,5-a]pyridine-7-carboxylate.

In title compound (Fig. 1) the the [1,2,4]triazolo[1,5-a]pyridine ring system is almost planar, as indicated by its r.m.s. deviation of 0.0068 Å and by the dihedral angle of 0.9 (3)° between the pyridine and triazole rings. The C10–C15 phenyl ring is tilted by 61.4 (3)° with respect to the mean plane through the fused-ring system. All bond lengths (Allen et al., 1987) and angles in the molecule are normal. In the crystal structure, centrosymmetrically related molecules form dimeric units by a pair of C—H···N intermolecular hydrogen bonds (Table 1).

Related literature top

For application of [1,2,4]triazolo[1,5-a]pyridine derivatives, see: Luo & Hu (2006); Liu & Hu (2002). For the synthesis of [1,2,4]triazolo[1,5-a]pyridine derivatives, see: Jones & Sliskovic (1983); Wang et al. (2003); Ge et al. (2009); Jia et al. (2010). For standard bond lengths, see: Allen et al. (1987).

Experimental top

Phenyl(1H-1,2,4-triazol-5-yl)methanone (6 mmol), ethyl 4-bromo-3-methylbut-2-enoate (12 mmol), potassium carbonate (1.8 g, 13.2 mmol) and DMF (30 ml) were added to a 100 ml round-bottomed flask and stirred for 8 h. The mixture was then poured into water (200 ml) and extracted with dichloromethane (3 × 50 ml). The organic layers were combined and dried over anhydrous Na₂SO₄, then filtered, and the mixture concentrated by rotary evaporation. The crude products were depurated by using column chromatography in 72% isolated yield. Crystals suitable for X-ray diffraction analysis were obtained by slow evaporation of a solution of the title compound in a hexane/ethyl acetate mixture (3:1 v/v) at room temperature over a period of one week.

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); 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 (Sheldrick, 2008).

Figures top

Fig. 1. The molecular structure of the title compouns, with displacement ellipsoids drawn at the 30% probability level.

Ethyl 6-methyl-8-phenyl-1,2,4-triazolo[1,5-a]pyridine-7-carboxylate top

Crystal data top

C₁₆H₁₅N₃O₂	F(000) = 592
M_r = 281.31	D_x = 1.252 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3034 reflections
a = 13.401 (3) Å	θ = 2.7–25.1°
b = 7.4825 (19) Å	µ = 0.09 mm⁻¹
c = 15.068 (4) Å	T = 298 K
β = 98.986 (4)°	Block, colourless
V = 1492.4 (7) Å³	0.23 × 0.19 × 0.15 mm
Z = 4

Data collection top

Brucker SMART APEXII CCD area-detector diffractometer	2611 independent reflections
Radiation source: fine-focus sealed tube	1920 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.086
phi and ω scans	θ_max = 25.0°, θ_min = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 1999)	h = −10→15
T_min = 0.981, T_max = 0.987	k = −8→7
7312 measured reflections	l = −17→17

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.049	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.152	H-atom parameters constrained
S = 1.05	w = 1/[σ²(F_o²) + (0.073P)² + 0.2662P] where P = (F_o² + 2F_c²)/3
2611 reflections	(Δ/σ)_max < 0.001
192 parameters	Δρ_max = 0.22 e Å⁻³
0 restraints	Δρ_min = −0.23 e Å⁻³

Crystal data top

C₁₆H₁₅N₃O₂	V = 1492.4 (7) Å³
M_r = 281.31	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 13.401 (3) Å	µ = 0.09 mm⁻¹
b = 7.4825 (19) Å	T = 298 K
c = 15.068 (4) Å	0.23 × 0.19 × 0.15 mm
β = 98.986 (4)°

Data collection top

Brucker SMART APEXII CCD area-detector diffractometer	2611 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 1999)	1920 reflections with I > 2σ(I)
T_min = 0.981, T_max = 0.987	R_int = 0.086
7312 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.049	0 restraints
wR(F²) = 0.152	H-atom parameters constrained
S = 1.05	Δρ_max = 0.22 e Å⁻³
2611 reflections	Δρ_min = −0.23 e Å⁻³
192 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.10885 (12)	0.7854 (2)	0.55820 (10)	0.0547 (4)
N2	0.09507 (14)	0.9165 (2)	0.61803 (11)	0.0672 (5)
N3	0.23653 (13)	0.7566 (2)	0.66890 (10)	0.0628 (5)
O1	0.25306 (14)	0.4080 (2)	0.34386 (12)	0.0912 (6)
O2	0.14672 (10)	0.22579 (18)	0.39941 (9)	0.0636 (4)
C1	0.2563 (2)	−0.0255 (4)	0.3838 (2)	0.0930 (8)
H1A	0.3166	0.0453	0.3874	0.140*
H1B	0.2629	−0.1306	0.3486	0.140*
H1C	0.2463	−0.0598	0.4432	0.140*
C2	0.16849 (19)	0.0806 (3)	0.34085 (16)	0.0752 (6)
H2A	0.1827	0.1295	0.2845	0.090*
H2B	0.1098	0.0035	0.3278	0.090*
C3	0.19373 (14)	0.3795 (3)	0.39345 (12)	0.0555 (5)
C4	0.16236 (13)	0.5171 (2)	0.45608 (12)	0.0499 (5)
C5	0.07336 (14)	0.6198 (3)	0.42544 (13)	0.0556 (5)
C6	0.04891 (14)	0.7524 (3)	0.47858 (13)	0.0589 (5)
H6	−0.0087	0.8208	0.4609	0.071*
C7	0.17325 (18)	0.8910 (3)	0.68132 (14)	0.0687 (6)
H7	0.1843	0.9626	0.7324	0.082*
C8	0.19436 (14)	0.6907 (2)	0.58965 (12)	0.0509 (5)
C9	0.22271 (13)	0.5487 (2)	0.53631 (12)	0.0488 (5)
C10	0.31516 (14)	0.4442 (3)	0.57064 (12)	0.0541 (5)
C11	0.40784 (15)	0.5273 (4)	0.58803 (16)	0.0791 (7)
H11	0.4132	0.6496	0.5789	0.095*
C14	0.3930 (2)	0.1653 (4)	0.62015 (18)	0.0902 (8)
H14	0.3876	0.0438	0.6315	0.108*
C15	0.30836 (17)	0.2630 (3)	0.58754 (14)	0.0698 (6)
H15	0.2457	0.2068	0.5767	0.084*
C16	0.01047 (17)	0.5868 (3)	0.33544 (15)	0.0759 (7)
H16A	−0.0466	0.6659	0.3276	0.114*
H16B	−0.0127	0.4652	0.3322	0.114*
H16C	0.0505	0.6081	0.2889	0.114*
C12	0.49383 (18)	0.4263 (5)	0.61947 (19)	0.1016 (10)
H12	0.5571	0.4802	0.6294	0.122*
C13	0.4843 (2)	0.2469 (5)	0.6356 (2)	0.1015 (10)
H13	0.5414	0.1804	0.6575	0.122*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0617 (9)	0.0450 (9)	0.0561 (9)	0.0084 (7)	0.0047 (7)	0.0023 (7)
N2	0.0850 (12)	0.0518 (10)	0.0632 (10)	0.0147 (9)	0.0069 (9)	−0.0068 (8)
N3	0.0732 (11)	0.0605 (10)	0.0531 (9)	0.0066 (9)	0.0045 (8)	−0.0003 (8)
O1	0.1124 (13)	0.0857 (12)	0.0881 (11)	−0.0218 (10)	0.0553 (10)	−0.0121 (9)
O2	0.0725 (9)	0.0494 (8)	0.0730 (9)	−0.0023 (7)	0.0240 (7)	−0.0091 (6)
C1	0.1027 (18)	0.0772 (17)	0.1035 (19)	0.0237 (15)	0.0294 (16)	−0.0102 (15)
C2	0.0908 (16)	0.0612 (13)	0.0759 (14)	0.0012 (12)	0.0202 (12)	−0.0175 (11)
C3	0.0584 (11)	0.0556 (12)	0.0530 (10)	−0.0017 (9)	0.0102 (9)	0.0014 (9)
C4	0.0528 (10)	0.0442 (10)	0.0535 (10)	−0.0008 (8)	0.0106 (8)	0.0044 (8)
C5	0.0560 (11)	0.0505 (11)	0.0581 (11)	0.0009 (9)	0.0023 (9)	0.0046 (9)
C6	0.0580 (11)	0.0506 (11)	0.0649 (12)	0.0104 (9)	−0.0006 (9)	0.0054 (10)
C7	0.0871 (15)	0.0588 (13)	0.0587 (12)	0.0090 (12)	0.0066 (11)	−0.0063 (10)
C8	0.0558 (10)	0.0467 (10)	0.0494 (10)	0.0031 (8)	0.0059 (8)	0.0071 (8)
C9	0.0520 (10)	0.0450 (10)	0.0505 (10)	0.0019 (8)	0.0112 (8)	0.0073 (8)
C10	0.0541 (10)	0.0622 (12)	0.0462 (10)	0.0089 (9)	0.0087 (8)	0.0030 (8)
C11	0.0578 (13)	0.0981 (18)	0.0817 (15)	−0.0013 (12)	0.0118 (11)	0.0211 (14)
C14	0.0914 (19)	0.0786 (17)	0.0925 (17)	0.0314 (15)	−0.0107 (14)	0.0037 (14)
C15	0.0719 (13)	0.0598 (13)	0.0730 (14)	0.0130 (11)	−0.0034 (11)	0.0006 (11)
C16	0.0772 (14)	0.0723 (15)	0.0710 (13)	0.0060 (12)	−0.0106 (11)	−0.0051 (11)
C12	0.0531 (13)	0.161 (3)	0.0913 (18)	0.0025 (17)	0.0116 (12)	0.0282 (19)
C13	0.0799 (19)	0.127 (3)	0.0966 (19)	0.0475 (19)	0.0126 (15)	0.0175 (19)

Geometric parameters (Å, º) top

N1—C6	1.358 (2)	C5—C16	1.501 (3)
N1—N2	1.364 (2)	C6—H6	0.9300
N1—C8	1.368 (2)	C7—H7	0.9300
N2—C7	1.316 (3)	C8—C9	1.420 (3)
N3—C8	1.333 (2)	C9—C10	1.488 (2)
N3—C7	1.347 (3)	C10—C11	1.377 (3)
O1—C3	1.192 (2)	C10—C15	1.385 (3)
O2—C3	1.322 (2)	C11—C12	1.397 (4)
O2—C2	1.458 (2)	C11—H11	0.9300
C1—C2	1.482 (3)	C14—C13	1.355 (4)
C1—H1A	0.9600	C14—C15	1.374 (3)
C1—H1B	0.9600	C14—H14	0.9300
C1—H1C	0.9600	C15—H15	0.9300
C2—H2A	0.9700	C16—H16A	0.9600
C2—H2B	0.9700	C16—H16B	0.9600
C3—C4	1.500 (3)	C16—H16C	0.9600
C4—C9	1.366 (3)	C12—C13	1.374 (5)
C4—C5	1.433 (3)	C12—H12	0.9300
C5—C6	1.347 (3)	C13—H13	0.9300

C6—N1—N2	126.33 (15)	N3—C7—H7	121.5
C6—N1—C8	124.03 (16)	N3—C8—N1	109.50 (17)
N2—N1—C8	109.64 (15)	N3—C8—C9	132.10 (17)
C7—N2—N1	101.54 (16)	N1—C8—C9	118.40 (15)
C8—N3—C7	102.27 (16)	C4—C9—C8	117.18 (16)
C3—O2—C2	117.72 (16)	C4—C9—C10	124.22 (16)
C2—C1—H1A	109.5	C8—C9—C10	118.60 (15)
C2—C1—H1B	109.5	C11—C10—C15	119.36 (19)
H1A—C1—H1B	109.5	C11—C10—C9	120.41 (19)
C2—C1—H1C	109.5	C15—C10—C9	120.21 (18)
H1A—C1—H1C	109.5	C10—C11—C12	119.5 (3)
H1B—C1—H1C	109.5	C10—C11—H11	120.3
O2—C2—C1	110.81 (19)	C12—C11—H11	120.3
O2—C2—H2A	109.5	C13—C14—C15	119.6 (3)
C1—C2—H2A	109.5	C13—C14—H14	120.2
O2—C2—H2B	109.5	C15—C14—H14	120.2
C1—C2—H2B	109.5	C14—C15—C10	120.8 (2)
H2A—C2—H2B	108.1	C14—C15—H15	119.6
O1—C3—O2	124.74 (19)	C10—C15—H15	119.6
O1—C3—C4	123.47 (19)	C5—C16—H16A	109.5
O2—C3—C4	111.78 (15)	C5—C16—H16B	109.5
C9—C4—C5	122.70 (17)	H16A—C16—H16B	109.5
C9—C4—C3	119.35 (16)	C5—C16—H16C	109.5
C5—C4—C3	117.77 (16)	H16A—C16—H16C	109.5
C6—C5—C4	118.08 (17)	H16B—C16—H16C	109.5
C6—C5—C16	120.25 (18)	C13—C12—C11	119.6 (3)
C4—C5—C16	121.63 (18)	C13—C12—H12	120.2
C5—C6—N1	119.61 (17)	C11—C12—H12	120.2
C5—C6—H6	120.2	C14—C13—C12	121.1 (2)
N1—C6—H6	120.2	C14—C13—H13	119.4
N2—C7—N3	117.05 (19)	C12—C13—H13	119.4
N2—C7—H7	121.5

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···N2ⁱ	0.93	2.49	3.332 (3)	151

Symmetry code: (i) −x, −y+2, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···N2ⁱ	0.93	2.49	3.332 (3)	151.2

Symmetry code: (i) −x, −y+2, −z+1.

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