Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S010827010001194X/qd0026sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S010827010001194X/qd0026Isup2.hkl |
CCDC reference: 152674
The title compound can be synthesized in three different ways (a-c): (a) a suspension of 5-ethyl-3-(4-methoxybenzylidene)hydrazino-1,2,4-triazino[5,6-b]indole (0.664 g, 2 mmol) in toluene (30 ml) was treated with 10% ethanolic iron(III) chloride solution (20 ml) and heated at reflux for 3 h. The mixture was evaporated to dryness and the obtained orange residue was triturated with water, filtered, washed with water, dried and crystallized from ethanol (yield 39%, m.p. 585 K). (b) A mixture of the aforementioned hydrazone (0,664 g, 2 mmol) and thionyl chloride (25 ml) was heated at reflux for 5 h. The mixture was evaporated and the obtained residue was crystallized from ethanol (yield 45%, m.p. 585 K). (c) A suspension of the same aforementioned hydrazone (0.664 g, 2 mmol) in dioxane (5 ml) was treated with 30% aqueous sodium hypochlorite solution (15 ml) and heated at 373 K for 10 min. After attaining ambient temperature, the product was filtered, washed with water, dried, and crystallized from ethanol (yield 52%, m.p. 585 K).
The low fraction of observed reflections with I > 2σ(I) to the total number of measured reflections, 1005/2935 for 2θmax = 50°, was due to the weak high-order reflections. If the original data is cut off at 2θ = 45°, the ratio of observed/total improves to 953/2171.
Data collection: CAD-4-PC Software (Enraf-Nonius, 1989); cell refinement: CAD-4-PC; data reduction: NRCVAX DATRD2 (Le Page & Gabe, 1979); program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL93 (Sheldrick, 1993).
C19H16N6O | Z = 2 |
Mr = 344.38 | F(000) = 360 |
Triclinic, P1 | Dx = 1.371 Mg m−3 |
a = 9.420 (3) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.805 (4) Å | Cell parameters from 25 reflections |
c = 11.228 (6) Å | θ = 3.0–16.5° |
α = 114.55 (4)° | µ = 0.09 mm−1 |
β = 114.67 (4)° | T = 293 K |
γ = 91.03 (3)° | Plate, orange |
V = 834.0 (8) Å3 | 0.50 × 0.31 × 0.07 mm |
Enraf-Nonius CAD-4 diffractometer | Rint = 0.000 |
ω–2θ scans | θmax = 25.0° |
Absorption correction: ψ scan (NRCVAX ABSORP; Gabe et al., 1989) | h = −11→11 |
Tmin = 0.777, Tmax = 0.996 | k = 0→11 |
2935 measured reflections | l = −13→13 |
2935 independent reflections | 3 standard reflections every 240 min |
1005 reflections with I > 2σ(I) | intensity decay: 1.3% |
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)] = 0.053 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.115 | H-atom parameters constrained |
S = 0.83 | w = 1/[σ2(Fo2) + (0.0706P)2] where P = (Fo2 + 2Fc2)/3 |
2935 reflections | (Δ/σ)max = 0.005 |
235 parameters | Δρmax = 0.19 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C19H16N6O | γ = 91.03 (3)° |
Mr = 344.38 | V = 834.0 (8) Å3 |
Triclinic, P1 | Z = 2 |
a = 9.420 (3) Å | Mo Kα radiation |
b = 9.805 (4) Å | µ = 0.09 mm−1 |
c = 11.228 (6) Å | T = 293 K |
α = 114.55 (4)° | 0.50 × 0.31 × 0.07 mm |
β = 114.67 (4)° |
Enraf-Nonius CAD-4 diffractometer | 1005 reflections with I > 2σ(I) |
Absorption correction: ψ scan (NRCVAX ABSORP; Gabe et al., 1989) | Rint = 0.000 |
Tmin = 0.777, Tmax = 0.996 | 3 standard reflections every 240 min |
2935 measured reflections | intensity decay: 1.3% |
2935 independent reflections |
R[F2 > 2σ(F2)] = 0.053 | 0 restraints |
wR(F2) = 0.115 | H-atom parameters constrained |
S = 0.83 | Δρmax = 0.19 e Å−3 |
2935 reflections | Δρmin = −0.24 e Å−3 |
235 parameters |
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 on F2 for ALL reflections except for 0 with very negative F2 or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating _R_factor_obs 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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.2446 (4) | −0.3329 (3) | −0.3136 (3) | 0.0725 (9) | |
N1 | −0.1436 (3) | 0.6069 (3) | 0.1793 (3) | 0.0524 (9) | |
N2 | −0.3057 (3) | 0.3585 (3) | −0.0108 (3) | 0.0503 (9) | |
N3 | 0.0058 (3) | 0.2897 (3) | 0.0251 (3) | 0.0418 (8) | |
N4 | −0.1388 (3) | 0.1865 (3) | −0.0751 (3) | 0.0417 (8) | |
N5 | −0.4024 (4) | 0.0917 (4) | −0.1913 (4) | 0.0606 (10) | |
N6 | −0.3248 (4) | −0.0222 (3) | −0.2422 (3) | 0.0564 (10) | |
C1 | 0.0214 (4) | 0.6701 (4) | 0.2675 (4) | 0.0471 (11) | |
C2 | 0.0996 (5) | 0.8177 (4) | 0.3845 (4) | 0.0609 (12) | |
H2 | 0.0429 | 0.8903 | 0.4136 | 0.073* | |
C3 | 0.2644 (5) | 0.8511 (5) | 0.4547 (4) | 0.0660 (13) | |
H3 | 0.3198 | 0.9490 | 0.5331 | 0.079* | |
C4 | 0.3526 (5) | 0.7435 (5) | 0.4132 (4) | 0.0644 (13) | |
H4 | 0.4643 | 0.7706 | 0.4643 | 0.077* | |
C5 | 0.2740 (4) | 0.5973 (4) | 0.2964 (4) | 0.0534 (11) | |
H5 | 0.3311 | 0.5251 | 0.2676 | 0.064* | |
C6 | 0.1075 (4) | 0.5617 (4) | 0.2236 (4) | 0.0403 (10) | |
C7 | −0.0119 (4) | 0.4235 (4) | 0.1048 (4) | 0.0389 (10) | |
C8 | −0.1666 (4) | 0.4570 (4) | 0.0838 (4) | 0.0426 (10) | |
C9 | −0.2880 (4) | 0.2163 (4) | −0.0908 (4) | 0.0493 (11) | |
C10 | −0.1707 (4) | 0.0326 (4) | −0.1744 (4) | 0.0462 (11) | |
C11 | −0.0529 (4) | −0.0537 (4) | −0.2007 (4) | 0.0444 (10) | |
C12 | 0.1101 (4) | 0.0048 (4) | −0.1304 (4) | 0.0566 (12) | |
H12 | 0.1518 | 0.1070 | −0.0573 | 0.068* | |
C13 | 0.2153 (5) | −0.0829 (4) | −0.1643 (4) | 0.0621 (12) | |
H13 | 0.3250 | −0.0399 | −0.1151 | 0.074* | |
C14 | 0.1534 (5) | −0.2355 (4) | −0.2728 (4) | 0.0543 (12) | |
C15 | −0.0082 (5) | −0.2966 (4) | −0.3430 (4) | 0.0634 (13) | |
H15 | −0.0495 | −0.3992 | −0.4151 | 0.076* | |
C16 | −0.1107 (5) | −0.2080 (4) | −0.3080 (4) | 0.0551 (12) | |
H16 | −0.2201 | −0.2518 | −0.3569 | 0.066* | |
C17 | 0.4115 (5) | −0.2754 (5) | −0.2433 (6) | 0.091 (2) | |
H17A | 0.4605 | −0.3557 | −0.2825 | 0.136* | |
H17B | 0.4542 | −0.2398 | −0.1388 | 0.136* | |
H17C | 0.4338 | −0.1914 | −0.2606 | 0.136* | |
C18 | −0.2738 (5) | 0.6873 (5) | 0.1877 (5) | 0.0790 (15) | |
H18A | −0.2421 | 0.7915 | 0.2055 | 0.095* | |
H18B | −0.3696 | 0.6349 | 0.0927 | 0.095* | |
C19 | −0.3139 (6) | 0.6951 (6) | 0.3044 (5) | 0.103 (2) | |
H19A | −0.3986 | 0.7484 | 0.3030 | 0.154* | |
H19B | −0.2207 | 0.7493 | 0.3994 | 0.154* | |
H19C | −0.3483 | 0.5926 | 0.2864 | 0.154* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.082 (2) | 0.049 (2) | 0.094 (2) | 0.021 (2) | 0.055 (2) | 0.026 (2) |
N1 | 0.041 (2) | 0.043 (2) | 0.063 (2) | 0.017 (2) | 0.027 (2) | 0.012 (2) |
N2 | 0.045 (2) | 0.042 (2) | 0.050 (2) | 0.008 (2) | 0.017 (2) | 0.013 (2) |
N3 | 0.039 (2) | 0.041 (2) | 0.038 (2) | 0.007 (2) | 0.013 (2) | 0.017 (2) |
N4 | 0.035 (2) | 0.035 (2) | 0.038 (2) | 0.000 (2) | 0.008 (2) | 0.012 (2) |
N5 | 0.048 (2) | 0.050 (2) | 0.062 (2) | 0.002 (2) | 0.016 (2) | 0.017 (2) |
N6 | 0.047 (2) | 0.041 (2) | 0.056 (2) | 0.001 (2) | 0.014 (2) | 0.011 (2) |
C1 | 0.044 (2) | 0.043 (3) | 0.045 (3) | 0.003 (2) | 0.022 (2) | 0.013 (2) |
C2 | 0.062 (3) | 0.043 (3) | 0.059 (3) | 0.012 (2) | 0.025 (2) | 0.011 (2) |
C3 | 0.066 (3) | 0.051 (3) | 0.045 (3) | −0.005 (2) | 0.017 (2) | 0.001 (2) |
C4 | 0.051 (3) | 0.064 (3) | 0.051 (3) | 0.003 (2) | 0.013 (2) | 0.014 (3) |
C5 | 0.054 (3) | 0.040 (3) | 0.047 (3) | 0.006 (2) | 0.016 (2) | 0.011 (2) |
C6 | 0.038 (2) | 0.038 (2) | 0.030 (2) | 0.002 (2) | 0.010 (2) | 0.009 (2) |
C7 | 0.034 (2) | 0.041 (3) | 0.038 (2) | 0.008 (2) | 0.016 (2) | 0.016 (2) |
C8 | 0.045 (3) | 0.038 (2) | 0.042 (3) | 0.010 (2) | 0.021 (2) | 0.015 (2) |
C9 | 0.041 (2) | 0.050 (3) | 0.040 (3) | −0.001 (2) | 0.011 (2) | 0.014 (2) |
C10 | 0.051 (3) | 0.032 (2) | 0.042 (3) | −0.003 (2) | 0.014 (2) | 0.014 (2) |
C11 | 0.049 (2) | 0.035 (2) | 0.038 (2) | 0.004 (2) | 0.015 (2) | 0.013 (2) |
C12 | 0.055 (3) | 0.029 (2) | 0.058 (3) | 0.003 (2) | 0.014 (2) | 0.009 (2) |
C13 | 0.058 (3) | 0.045 (3) | 0.069 (3) | 0.011 (2) | 0.026 (2) | 0.018 (3) |
C14 | 0.065 (3) | 0.041 (3) | 0.058 (3) | 0.014 (2) | 0.031 (2) | 0.022 (2) |
C15 | 0.079 (3) | 0.032 (2) | 0.057 (3) | 0.006 (2) | 0.033 (3) | 0.002 (2) |
C16 | 0.058 (3) | 0.049 (3) | 0.044 (3) | 0.002 (2) | 0.019 (2) | 0.015 (2) |
C17 | 0.089 (4) | 0.065 (3) | 0.148 (5) | 0.029 (3) | 0.079 (4) | 0.051 (3) |
C18 | 0.079 (3) | 0.067 (3) | 0.075 (4) | 0.018 (2) | 0.027 (3) | 0.029 (3) |
C19 | 0.109 (4) | 0.127 (5) | 0.104 (5) | 0.039 (3) | 0.075 (4) | 0.054 (4) |
O1—C14 | 1.363 (4) | C1—C6 | 1.401 (4) |
O1—C17 | 1.405 (4) | C2—C3 | 1.373 (5) |
N1—C8 | 1.357 (4) | C3—C4 | 1.402 (5) |
N1—C1 | 1.396 (4) | C4—C5 | 1.383 (5) |
N1—C18 | 1.485 (4) | C5—C6 | 1.386 (4) |
N2—C8 | 1.311 (4) | C6—C7 | 1.439 (4) |
N2—C9 | 1.368 (4) | C7—C8 | 1.442 (4) |
N3—C7 | 1.307 (4) | C10—C11 | 1.461 (5) |
N3—N4 | 1.368 (4) | C11—C12 | 1.375 (5) |
N4—C10 | 1.384 (4) | C11—C16 | 1.394 (4) |
N4—C9 | 1.394 (4) | C12—C13 | 1.392 (5) |
N5—C9 | 1.311 (4) | C13—C14 | 1.387 (5) |
N5—N6 | 1.398 (4) | C14—C15 | 1.368 (5) |
N6—C10 | 1.298 (4) | C15—C16 | 1.380 (5) |
C1—C2 | 1.392 (5) | C18—C19 | 1.482 (5) |
C14—O1—C17 | 118.3 (3) | N3—C7—C8 | 123.2 (3) |
C8—N1—C1 | 108.5 (3) | C6—C7—C8 | 107.0 (3) |
C8—N1—C18 | 125.0 (3) | N2—C8—N1 | 125.9 (3) |
C1—N1—C18 | 126.6 (3) | N2—C8—C7 | 125.6 (3) |
C8—N2—C9 | 111.6 (3) | N1—C8—C7 | 108.5 (3) |
C7—N3—N4 | 111.6 (3) | N5—C9—N2 | 127.0 (4) |
N3—N4—C10 | 129.3 (3) | N5—C9—N4 | 110.4 (3) |
N3—N4—C9 | 125.3 (3) | N2—C9—N4 | 122.6 (3) |
C10—N4—C9 | 105.3 (3) | N6—C10—N4 | 108.0 (3) |
C9—N5—N6 | 105.5 (3) | N6—C10—C11 | 125.6 (3) |
C10—N6—N5 | 110.8 (3) | N4—C10—C11 | 126.4 (3) |
C2—C1—N1 | 128.3 (4) | C12—C11—C16 | 117.1 (3) |
C2—C1—C6 | 121.3 (3) | C12—C11—C10 | 125.6 (3) |
N1—C1—C6 | 110.5 (3) | C16—C11—C10 | 117.3 (3) |
C3—C2—C1 | 116.8 (4) | C11—C12—C13 | 122.6 (3) |
C2—C3—C4 | 122.7 (4) | C14—C13—C12 | 118.8 (4) |
C5—C4—C3 | 120.1 (4) | O1—C14—C15 | 116.3 (4) |
C4—C5—C6 | 118.1 (3) | O1—C14—C13 | 124.0 (4) |
C5—C6—C1 | 121.0 (3) | C15—C14—C13 | 119.6 (4) |
C5—C6—C7 | 133.5 (3) | C14—C15—C16 | 120.8 (4) |
C1—C6—C7 | 105.4 (3) | C15—C16—C11 | 121.1 (4) |
N3—C7—C6 | 129.7 (3) | C19—C18—N1 | 114.4 (4) |
Experimental details
Crystal data | |
Chemical formula | C19H16N6O |
Mr | 344.38 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 9.420 (3), 9.805 (4), 11.228 (6) |
α, β, γ (°) | 114.55 (4), 114.67 (4), 91.03 (3) |
V (Å3) | 834.0 (8) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.50 × 0.31 × 0.07 |
Data collection | |
Diffractometer | Enraf-Nonius CAD-4 diffractometer |
Absorption correction | ψ scan (NRCVAX ABSORP; Gabe et al., 1989) |
Tmin, Tmax | 0.777, 0.996 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2935, 2935, 1005 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.053, 0.115, 0.83 |
No. of reflections | 2935 |
No. of parameters | 235 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.19, −0.24 |
Computer programs: CAD-4-PC Software (Enraf-Nonius, 1989), CAD-4-PC, NRCVAX DATRD2 (Le Page & Gabe, 1979), SHELXS86 (Sheldrick, 1990), SHELXL93 (Sheldrick, 1993).
O1—C14 | 1.363 (4) | N4—C10 | 1.384 (4) |
O1—C17 | 1.405 (4) | N4—C9 | 1.394 (4) |
N1—C8 | 1.357 (4) | N5—C9 | 1.311 (4) |
N1—C1 | 1.396 (4) | N5—N6 | 1.398 (4) |
N1—C18 | 1.485 (4) | N6—C10 | 1.298 (4) |
N2—C8 | 1.311 (4) | C1—C6 | 1.401 (4) |
N2—C9 | 1.368 (4) | C6—C7 | 1.439 (4) |
N3—C7 | 1.307 (4) | C7—C8 | 1.442 (4) |
N3—N4 | 1.368 (4) | C10—C11 | 1.461 (5) |
C14—O1—C17 | 118.3 (3) | C1—C6—C7 | 105.4 (3) |
C8—N1—C1 | 108.5 (3) | N3—C7—C6 | 129.7 (3) |
C8—N1—C18 | 125.0 (3) | N3—C7—C8 | 123.2 (3) |
C1—N1—C18 | 126.6 (3) | C6—C7—C8 | 107.0 (3) |
C8—N2—C9 | 111.6 (3) | N2—C8—N1 | 125.9 (3) |
C7—N3—N4 | 111.6 (3) | N2—C8—C7 | 125.6 (3) |
N3—N4—C10 | 129.3 (3) | N1—C8—C7 | 108.5 (3) |
N3—N4—C9 | 125.3 (3) | N5—C9—N2 | 127.0 (4) |
C10—N4—C9 | 105.3 (3) | N5—C9—N4 | 110.4 (3) |
C9—N5—N6 | 105.5 (3) | N2—C9—N4 | 122.6 (3) |
C10—N6—N5 | 110.8 (3) | N6—C10—N4 | 108.0 (3) |
C2—C1—N1 | 128.3 (4) | N6—C10—C11 | 125.6 (3) |
N1—C1—C6 | 110.5 (3) | N4—C10—C11 | 126.4 (3) |
C5—C6—C7 | 133.5 (3) |
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Vauable medicinal applications and biological activities are known to be associated with the 1,2,4-triazolo-1,2,4-triazino[5,6-b]indole structure (Katz & Margalith, 1984). One of the synthetic pathways to obtain the 10-substituted derivatives of these compounds is the oxidative cyclization of 5-substituted-3-alkylidene- and 3-arylidenehydrazino-1,2,4-triazino[5,6-b]indoles (Shaban et al., 1993, 1999, 2000; Rashed et al., 1998). Assignment of structures to the obtained products was inconclusive whether they are the linearly annelated 1,2,4-triazolo[4',3':2,3]1,2,4-triazino[5,6-b]indoles such as the title compound, (I), (Shaban et al., 1993, 1999, 2000) or the angular-annelated 1,2,4-triazolo[3',4':3,4]-1,2,4-triazino[5,6-b]indole regioisomers, (II) (Holla & Udupa, 1990; Rashed et al., 1998). The present work has been initiated to settle this contradiction. The title compound, (I), was prepared by oxidative cyclization of 3-(4-methoxybenzylidene)hydrazino-1,2,4-triazino[5,6-b]indole with 10% ethanolic iron(III) chloride, thionyl chloride or 30% aqueous sodium hypochlorite in dioxane. The determined molecular structure revealed that the four-ring system corresponds to the linearly annelated structure (I) and not the angularly annelated structure (II). The skeleton is approximately planar except for the ethyl group. Bond distances showed localization of the N2—C8 and N3—C7 π bonds of the 1,2,4-trizole ring as well as N5—C9 and N6—C10 π bonds of the 1,2,4-triazine ring.