Ethyl 1-(6-chloro-3-pyridylmeth­yl)-5-methyl-1H-1,2,3-triazole-4-carboxyl­ate

In the title compound, C₁₂H₁₃ClN₄O₂, the triazole ring carries methyl and ethoxy­carbonyl groups, and is bound via a methyl­ene bridge to a chloro­pyridine unit. There is evidence for significant electron delocalization in the triazolyl system. Intra­molecular C—H...O and inter­molecular C—H...N hydrogen bonds stabilize the structure.

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.039
• wR factor = 0.105
• Data-to-parameter ratio = 14.1

checkCIF/PLATON results

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Alert level C
ABSTY03_ALERT_1_C  The _exptl_absorpt_correction_type has been given as none.
            However values have been given for Tmin and Tmax. Remove
            these if an absorption correction has not been applied.
  From the CIF: _exptl_absorpt_correction_T_min   0.866
  From the CIF: _exptl_absorpt_correction_T_max   0.909
            Value of measurement temperature given =   291.000
            Value of melting point given =     0.000
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C1

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

[1,2,3]-Triazoles have been widely used in pharmaceuticals, agrochemicals, dyes, photographic materials, and in corrosion inhibition (Fan & Katritzky, 1996; Dehne,1994; Abu-Orabi et al., 1989). Since the structure-activity relationship is very useful in the rational design of pharmaceuticals and agrochemicals. We report here the crystal structure of the title compound, (I) (Fig. 1), which was synthesized by introducing pyridine rings into a 1,2,3-triazole molecular framework.

The C—N bonds are significantly shorter than a normal single C—N bond [1.47 Å; Sasada, 1984], and closer to the value for a C=N bond [1.28 Å; Wang et al., 1998]. This indicates significant electron delocalization in the triazolyl system.

Intramolecular C—H···O and intermolecular C—H···N hydrogen bonds contribute strongly to the stability of the molecular configuration (Table 1, Fig. 2).

Related literature

For applications of triazoles, see: Abu-Orabi et al. (1989); Fan & Katritzky (1996); Dehne (1994); Wang et al. (1998). For bond-length data, see: Sasada (1984).

S2. Experimental

Ethyl acetylacetate (2 mmol) and 5-azidomethyl-2-chloropyridine (2 mmol) were added to a suspension of milled potassium carbonate (2 mmol) in DMSO (10 ml). The mixture was stirred at room temperature for 6 h (monitored by thin-layer chromatography) and poured to water (50 ml). The solid was collected by filtration, washed with water and diethyl ether, respectively, and dried to give 0.52 g of the title compound (yield 91%). Colourless crystals of (I) suitable for X-ray structure analysis were grown from acetone and petroleum ether (2:1, v/v).

S3. Refinement

H atoms were placed at calculated positions, with C-H distances of 0.93 (aromatic CH), 0.97 (CH₃) and 0.97Å (CH₂). They were refined using a riding model, for methyl H atoms, U_iso(H) = 1.5U_eq(C); for all other H atoms, U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); 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

	Fig. 1. View of the molecular structure of (I), showing the atom labelling schemeand with displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. A partial view of the crystal packing of (I), showing the formation of C—H···O and C—H···N hydrogen-bonds (dashed lines).

Ethyl 1-(6-chloro-3-pyridylmethyl)-5-methyl-1H-1,2,3- triazole-4-carboxylate

Crystal data

C12H13ClN4O2	F(000) = 584
Mr = 280.71	Dx = 1.416 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3288 reflections
a = 24.984 (4) Å	θ = 3.3–25.5°
b = 4.3919 (8) Å	µ = 0.29 mm^−1
c = 12.040 (2) Å	T = 291 K
β = 94.415 (2)°	Block, colourless
V = 1317.2 (4) Å^3	0.46 × 0.38 × 0.33 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1991 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.023
Graphite monochromator	θmax = 25.5°, θmin = 3.3°
ϕ and ω scans	h = −30→29
9219 measured reflections	k = −5→5
2450 independent reflections	l = −14→14

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.105	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0461P)^2 + 0.4886P] where P = (Fo^2 + 2Fc^2)/3
2450 reflections	(Δ/σ)max < 0.001
174 parameters	Δρmax = 0.19 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.46436 (2)	0.66788 (16)	0.65329 (5)	0.0704 (2)
O1	0.11409 (5)	0.5500 (3)	0.20263 (11)	0.0531 (4)
O2	0.09737 (6)	0.7643 (4)	0.36514 (13)	0.0737 (5)
N1	0.37666 (7)	0.9857 (5)	0.61900 (13)	0.0649 (5)
N2	0.25163 (6)	1.1289 (3)	0.32725 (12)	0.0424 (4)
N3	0.25643 (6)	0.9861 (4)	0.22765 (12)	0.0489 (4)
N4	0.21318 (6)	0.8240 (4)	0.20603 (13)	0.0471 (4)
C1	0.41512 (7)	0.8561 (5)	0.56801 (16)	0.0484 (5)
C2	0.41911 (8)	0.8610 (6)	0.45476 (17)	0.0593 (6)
H2	0.4473	0.7647	0.4228	0.071*
C3	0.37992 (8)	1.0133 (6)	0.39049 (16)	0.0576 (6)
H3	0.3814	1.0215	0.3136	0.069*
C4	0.33851 (7)	1.1538 (4)	0.43968 (14)	0.0426 (4)
C5	0.33924 (9)	1.1340 (6)	0.55394 (16)	0.0625 (6)
H5	0.3118	1.2305	0.5885	0.075*
C6	0.29525 (8)	1.3267 (5)	0.37236 (17)	0.0507 (5)
H6A	0.2806	1.4811	0.4191	0.061*
H6B	0.3109	1.4293	0.3113	0.061*
C7	0.20468 (7)	1.0550 (4)	0.36960 (14)	0.0415 (4)
C8	0.18046 (7)	0.8611 (4)	0.29077 (14)	0.0413 (4)
C9	0.18798 (9)	1.1716 (5)	0.47790 (16)	0.0597 (6)
H9A	0.2023	1.0422	0.5372	0.090*
H9B	0.1495	1.1728	0.4764	0.090*
H9C	0.2013	1.3748	0.4899	0.090*
C10	0.12697 (8)	0.7226 (5)	0.29187 (16)	0.0477 (5)
C11	0.06017 (8)	0.4189 (6)	0.19684 (19)	0.0606 (6)
H11A	0.0336	0.5791	0.1999	0.073*
H11B	0.0567	0.2824	0.2592	0.073*
C12	0.05159 (10)	0.2481 (6)	0.0894 (2)	0.0700 (7)
H12A	0.0555	0.3845	0.0283	0.105*
H12B	0.0161	0.1623	0.0833	0.105*
H12C	0.0776	0.0878	0.0878	0.105*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0538 (3)	0.0928 (5)	0.0629 (4)	0.0083 (3)	−0.0057 (2)	0.0110 (3)
O1	0.0436 (7)	0.0630 (9)	0.0533 (8)	−0.0077 (6)	0.0074 (6)	−0.0061 (7)
O2	0.0623 (9)	0.1011 (13)	0.0607 (9)	−0.0154 (9)	0.0240 (8)	−0.0149 (9)
N1	0.0567 (10)	0.1005 (15)	0.0377 (9)	0.0146 (10)	0.0050 (8)	−0.0002 (10)
N2	0.0477 (8)	0.0423 (8)	0.0367 (8)	0.0002 (7)	0.0010 (6)	0.0047 (7)
N3	0.0515 (9)	0.0565 (10)	0.0392 (8)	−0.0032 (8)	0.0071 (7)	−0.0004 (7)
N4	0.0486 (9)	0.0538 (10)	0.0391 (8)	−0.0028 (8)	0.0047 (7)	−0.0002 (7)
C1	0.0432 (10)	0.0573 (12)	0.0444 (10)	−0.0048 (9)	0.0015 (8)	0.0010 (9)
C2	0.0496 (11)	0.0821 (16)	0.0476 (11)	0.0122 (11)	0.0130 (9)	−0.0023 (11)
C3	0.0568 (12)	0.0809 (16)	0.0362 (10)	0.0054 (11)	0.0110 (9)	0.0024 (10)
C4	0.0457 (10)	0.0429 (10)	0.0392 (10)	−0.0068 (8)	0.0029 (7)	−0.0024 (8)
C5	0.0570 (12)	0.0909 (17)	0.0404 (11)	0.0193 (12)	0.0078 (9)	−0.0083 (11)
C6	0.0559 (11)	0.0436 (11)	0.0515 (11)	−0.0048 (9)	−0.0017 (9)	0.0015 (9)
C7	0.0480 (10)	0.0422 (10)	0.0342 (9)	0.0067 (8)	0.0022 (7)	0.0066 (8)
C8	0.0448 (10)	0.0443 (10)	0.0349 (9)	0.0038 (8)	0.0034 (7)	0.0052 (8)
C9	0.0690 (13)	0.0692 (15)	0.0416 (11)	0.0010 (12)	0.0092 (9)	−0.0065 (10)
C10	0.0468 (10)	0.0517 (11)	0.0447 (10)	0.0020 (9)	0.0050 (8)	0.0046 (9)
C11	0.0448 (11)	0.0683 (14)	0.0692 (14)	−0.0100 (10)	0.0085 (10)	−0.0011 (11)
C12	0.0587 (13)	0.0816 (17)	0.0690 (15)	−0.0187 (12)	0.0004 (11)	−0.0038 (13)

Geometric parameters (Å, º)

Cl1—C1	1.748 (2)	C4—C6	1.505 (3)
O1—C10	1.334 (2)	C5—H5	0.9300
O1—C11	1.462 (2)	C6—H6A	0.9700
O2—C10	1.208 (2)	C6—H6B	0.9700
N1—C1	1.310 (3)	C7—C8	1.380 (3)
N1—C5	1.341 (3)	C7—C9	1.490 (3)
N2—C7	1.354 (2)	C8—C10	1.469 (3)
N2—N3	1.367 (2)	C9—H9A	0.9600
N2—C6	1.465 (2)	C9—H9B	0.9600
N3—N4	1.303 (2)	C9—H9C	0.9600
N4—C8	1.365 (2)	C11—C12	1.496 (3)
C1—C2	1.375 (3)	C11—H11A	0.9700
C2—C3	1.374 (3)	C11—H11B	0.9700
C2—H2	0.9300	C12—H12A	0.9600
C3—C4	1.377 (3)	C12—H12B	0.9600
C3—H3	0.9300	C12—H12C	0.9600
C4—C5	1.377 (3)
C10—O1—C11	115.24 (15)	N2—C7—C8	103.62 (15)
C1—N1—C5	116.16 (17)	N2—C7—C9	123.82 (17)
C7—N2—N3	110.96 (15)	C8—C7—C9	132.56 (18)
C7—N2—C6	130.06 (16)	N4—C8—C7	109.36 (16)
N3—N2—C6	118.97 (15)	N4—C8—C10	123.69 (16)
N4—N3—N2	107.36 (14)	C7—C8—C10	126.89 (16)
N3—N4—C8	108.69 (15)	C7—C9—H9A	109.5
N1—C1—C2	124.75 (19)	C7—C9—H9B	109.5
N1—C1—Cl1	116.01 (15)	H9A—C9—H9B	109.5
C2—C1—Cl1	119.23 (16)	C7—C9—H9C	109.5
C3—C2—C1	117.59 (18)	H9A—C9—H9C	109.5
C3—C2—H2	121.2	H9B—C9—H9C	109.5
C1—C2—H2	121.2	O2—C10—O1	123.45 (18)
C2—C3—C4	120.15 (18)	O2—C10—C8	123.52 (19)
C2—C3—H3	119.9	O1—C10—C8	113.02 (16)
C4—C3—H3	119.9	O1—C11—C12	107.99 (17)
C5—C4—C3	116.66 (18)	O1—C11—H11A	110.1
C5—C4—C6	121.56 (17)	C12—C11—H11A	110.1
C3—C4—C6	121.77 (17)	O1—C11—H11B	110.1
N1—C5—C4	124.68 (19)	C12—C11—H11B	110.1
N1—C5—H5	117.7	H11A—C11—H11B	108.4
C4—C5—H5	117.7	C11—C12—H12A	109.5
N2—C6—C4	112.53 (15)	C11—C12—H12B	109.5
N2—C6—H6A	109.1	H12A—C12—H12B	109.5
C4—C6—H6A	109.1	C11—C12—H12C	109.5
N2—C6—H6B	109.1	H12A—C12—H12C	109.5
C4—C6—H6B	109.1	H12B—C12—H12C	109.5
H6A—C6—H6B	107.8
C7—N2—N3—N4	0.3 (2)	N3—N2—C7—C8	−0.43 (19)
C6—N2—N3—N4	179.64 (15)	C6—N2—C7—C8	−179.72 (17)
N2—N3—N4—C8	0.0 (2)	N3—N2—C7—C9	179.32 (17)
C5—N1—C1—C2	−0.5 (3)	C6—N2—C7—C9	0.0 (3)
C5—N1—C1—Cl1	179.07 (18)	N3—N4—C8—C7	−0.3 (2)
N1—C1—C2—C3	0.1 (4)	N3—N4—C8—C10	177.11 (17)
Cl1—C1—C2—C3	−179.46 (17)	N2—C7—C8—N4	0.5 (2)
C1—C2—C3—C4	−0.1 (3)	C9—C7—C8—N4	−179.3 (2)
C2—C3—C4—C5	0.5 (3)	N2—C7—C8—C10	−176.87 (17)
C2—C3—C4—C6	179.1 (2)	C9—C7—C8—C10	3.4 (3)
C1—N1—C5—C4	1.0 (4)	C11—O1—C10—O2	1.9 (3)
C3—C4—C5—N1	−1.0 (4)	C11—O1—C10—C8	−177.09 (17)
C6—C4—C5—N1	−179.6 (2)	N4—C8—C10—O2	−177.4 (2)
C7—N2—C6—C4	93.0 (2)	C7—C8—C10—O2	−0.4 (3)
N3—N2—C6—C4	−86.3 (2)	N4—C8—C10—O1	1.6 (3)
C5—C4—C6—N2	−96.2 (2)	C7—C8—C10—O1	178.57 (17)
C3—C4—C6—N2	85.3 (2)	C10—O1—C11—C12	176.97 (19)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5···N3^i	0.93	2.57	3.479 (3)	164
C9—H9A···N4^ii	0.96	2.59	3.523 (3)	164
C9—H9B···O2	0.96	2.54	3.114 (3)	119

Symmetry codes: (i) x, −y+5/2, z+1/2; (ii) x, −y+3/2, z+1/2.