5-Methyl-1,2,4-triazolo[1,5-a]pyrimidine-6-carbonitrile

The title compound, C₇H₅N₅, was designed and synthesized as a potential anti­tumour agent. The mol­ecules are located on crystallographic mirror planes. The electron-accepting 6-cyano group has no effect on the π-electron cloud of the heterocyclic system. The mol­ecular packing is governed by C—H...N inter­molecular hydrogen bonds, which link the mol­ecules into chains running along the c axis.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.053
• wR factor = 0.147
• Data-to-parameter ratio = 14.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT371_ALERT_2_C Long   C(sp2)-C(sp1) Bond  C6     -   C10    ...       1.44 Ang.
PLAT380_ALERT_4_C Check Incorrectly? Oriented X(sp2)-Methyl Moiety         C9

   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

   0 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
   1 ALERT type 4 Improvement, methodology, query or suggestion


checkCIF publication errors

Alert level A
PUBL024_ALERT_1_A The number of authors is greater than 5.
              Please specify the role of each of the co-authors
              for your paper.

Author Response: The six authors in the present work were involved in the following activities. Synthesis of the compound (P.\<C. & V.M.), preparation of the suitable crystals by a special (vapour diffusion) technique (S.K.), measurement of the data and searching of the CSD (F.G.), solution and refinement of the structure, evaluation of the literature data and preparation of the article (text + figures, J.L. & V.K.).

   1 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

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Computing details

Data collection: XSCANS (Siemens, 1991); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLUTON92 (Spek, 1992); software used to prepare material for publication: SHELXL97.

5-Methyl-1,2,4-triazolo[1,5-a]pyrimidine-6-carbonitrile

Crystal data

C7H5N5	F(000) = 164
Mr = 159.16	Dx = 1.427 Mg m^−3
Monoclinic, P21/m	Melting point: 418 K
Hall symbol: -P 2yb	Mo Kα radiation, λ = 0.71073 Å
a = 7.105 (2) Å	Cell parameters from 20 reflections
b = 6.413 (2) Å	θ = 7–20°
c = 8.190 (3) Å	µ = 0.10 mm^−1
β = 96.82 (3)°	T = 296 K
V = 370.5 (2) Å^3	Prism, orange
Z = 2	0.30 × 0.20 × 0.15 mm

Data collection

Siemens P4 diffractometer	Rint = 0.040
Radiation source: fine-focus sealed tube	θmax = 30.0°, θmin = 2.5°
Graphite monochromator	h = −1→9
ω/2θ scans	k = −1→9
1628 measured reflections	l = −11→11
1165 independent reflections	3 standard reflections every 97 reflections
723 reflections with I > 2σ(I)	intensity decay: 2%

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)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.147	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0688P)^2 + 0.0536P] where P = (Fo^2 + 2Fc^2)/3
1165 reflections	(Δ/σ)max = 0.001
80 parameters	Δρmax = 0.20 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.3528 (4)	0.2500	0.6871 (2)	0.0569 (6)
C2	0.5230 (4)	0.2500	0.6295 (3)	0.0548 (7)
H2	0.6353	0.2500	0.7006	0.066*
N3	0.5243 (3)	0.2500	0.4680 (2)	0.0460 (5)
N4	0.3342 (2)	0.2500	0.4157 (2)	0.0354 (4)
C5	0.2534 (3)	0.2500	0.2566 (3)	0.0369 (5)
C6	0.0589 (3)	0.2500	0.2396 (3)	0.0420 (6)
C7	−0.0394 (4)	0.2500	0.3799 (3)	0.0508 (6)
H7	−0.1712	0.2500	0.3627	0.061*
N8	0.0410 (3)	0.2500	0.5318 (3)	0.0524 (6)
C8A	0.2329 (4)	0.2500	0.5508 (3)	0.0424 (6)
C9	0.3792 (4)	0.2500	0.1248 (3)	0.0541 (7)
H9A	0.307 (4)	0.2500	0.019 (4)	0.068 (9)*
H9B	0.462 (4)	0.125 (4)	0.136 (3)	0.107 (9)*
C10	−0.0494 (4)	0.2500	0.0799 (3)	0.0542 (7)
N10	−0.1435 (4)	0.2500	−0.0423 (3)	0.0804 (9)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0785 (17)	0.0606 (14)	0.0297 (10)	0.000	−0.0018 (10)	0.000
C2	0.0581 (16)	0.0543 (15)	0.0458 (13)	0.000	−0.0198 (12)	0.000
N3	0.0365 (10)	0.0552 (12)	0.0425 (11)	0.000	−0.0109 (8)	0.000
N4	0.0336 (9)	0.0414 (10)	0.0300 (8)	0.000	−0.0017 (7)	0.000
C5	0.0383 (11)	0.0433 (12)	0.0276 (9)	0.000	−0.0025 (8)	0.000
C6	0.0359 (11)	0.0453 (13)	0.0425 (12)	0.000	−0.0054 (9)	0.000
C7	0.0378 (12)	0.0545 (15)	0.0606 (15)	0.000	0.0079 (11)	0.000
N8	0.0523 (13)	0.0584 (13)	0.0492 (13)	0.000	0.0175 (10)	0.000
C8A	0.0551 (14)	0.0411 (12)	0.0318 (10)	0.000	0.0080 (10)	0.000
C9	0.0517 (15)	0.079 (2)	0.0323 (12)	0.000	0.0062 (10)	0.000
C10	0.0435 (13)	0.0637 (17)	0.0515 (14)	0.000	−0.0112 (11)	0.000
N10	0.0667 (16)	0.105 (2)	0.0615 (16)	0.000	−0.0272 (13)	0.000

Geometric parameters (Å, º)

N1—C8A	1.321 (3)	C6—C7	1.414 (3)
N1—C2	1.350 (4)	C6—C10	1.437 (3)
C2—N3	1.323 (3)	C7—N8	1.306 (3)
C2—H2	0.93	C7—H7	0.93
N3—N4	1.368 (3)	N8—C8A	1.354 (3)
N4—C5	1.360 (3)	C9—H9A	0.95 (3)
N4—C8A	1.390 (3)	C9—H9B	0.99 (3)
C5—C6	1.372 (3)	C10—N10	1.136 (3)
C5—C9	1.482 (3)
C8A—N1—C2	102.7 (2)	C7—C6—C10	118.5 (2)
N3—C2—N1	117.5 (2)	N8—C7—C6	124.9 (2)
N3—C2—H2	121.2	N8—C7—H7	117.6
N1—C2—H2	121.2	C6—C7—H7	117.6
C2—N3—N4	100.9 (2)	C7—N8—C8A	115.5 (2)
C5—N4—N3	126.10 (18)	N1—C8A—N8	129.6 (2)
C5—N4—C8A	124.25 (19)	N1—C8A—N4	109.2 (2)
N3—N4—C8A	109.65 (18)	N8—C8A—N4	121.2 (2)
N4—C5—C6	113.77 (19)	C5—C9—H9A	111.0 (18)
N4—C5—C9	118.4 (2)	C5—C9—H9B	109.7 (16)
C6—C5—C9	127.8 (2)	H9A—C9—H9B	109.2 (18)
C5—C6—C7	120.4 (2)	N10—C10—C6	176.4 (3)
C5—C6—C10	121.1 (2)
C8A—N1—C2—N3	0.0	C5—C6—C7—N8	0.0
N1—C2—N3—N4	0.0	C10—C6—C7—N8	180.0
C2—N3—N4—C5	180.0	C6—C7—N8—C8A	0.0
C2—N3—N4—C8A	0.0	C2—N1—C8A—N8	180.0
N3—N4—C5—C6	180.0	C2—N1—C8A—N4	0.0
C8A—N4—C5—C6	0.0	C7—N8—C8A—N1	180.0
N3—N4—C5—C9	0.0	C7—N8—C8A—N4	0.0
C8A—N4—C5—C9	180.0	C5—N4—C8A—N1	180.0
N4—C5—C6—C7	0.0	N3—N4—C8A—N1	0.0
C9—C5—C6—C7	180.0	C5—N4—C8A—N8	0.0
N4—C5—C6—C10	180.0	N3—N4—C8A—N8	180.0
C9—C5—C6—C10	0.0

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···N10^i	0.93	2.47	3.366 (4)	161
C7—H7···N3^ii	0.93	2.42	3.265 (4)	151

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