organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Ethyl 3-(3-oxo-3,4-di­hydro­quinoxalin-2-yl)propano­ate

aInstitute of Chemistry, University of Punjab, New Campus, Lahore, Pakistan, bDepartment of Chemistry, GC University, Lahore 54000, Pakistan, and cDepartment of Chemistry, Gomal University, D. I. Khan, Pakistan
*Correspondence e-mail: munawaralimunawar@yahoo.com

(Received 13 November 2010; accepted 13 November 2010; online 20 November 2010)

In the title compound, C13H14N2O3, the fused ring system is almost planar (r.m.s. deviation = 0.015 Å). The r.m.s. deviation for all the non-H atoms of the mol­ecule is 0.065Å. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds generate polymeric chains along the b axis containing alternating centrsymmetric R22(8) and R22(20) loops.

Related literature

For the synthesis, see: Taylor et al. (1965[Taylor, E. C., McKillop, A. & Ross, R. E. (1965). J. Am. Chem. Soc. 87, 1990-1995.]). For the biological activity of benzopyrazines, see: Sona et al. (1998[Sona, P., Carta, A. Loriga, M., Zanetti, S., & Sechi, L. (1998). Farmaco, 53, 455-461.]); Cai et al. (1997[Cai, S. X., Huang, J. C., Espitia, S. A., Tran, M., Ilyin, V. I., Hawkinson, J. E., Woodward, R. M., Weber, E. & Keana, F. M. (1997). J Med. Chem. 40, 3679-3686.]); Toshima et al. (2003[Toshima, K., Kimura, T., Takano, O. T., Shima, Y., Umerzawa, K. & Matsumura, S. (2003). Tetrahedron, 59, 7057-7067.]); Benbow et al. (2007[Benbow, J. W., Chu-Moyer, Y. M. & Kung, D. W. (2007). Patent No. US 7 202 245 B2,]); Sarges et al. (1990[Sarges, R., Howard, H. R., Browne, R. G., Lebel, L. A., Seymour, P. A. & Koe, B. K. (1990). J. Med. Chem. 33, 2240-2254.]); Smits et al. (2008[Smits, R. A., Lim, H. D., Hanzer, A., Zuiderveld, O. P., Guaita, E., Adami, M., Coruzzi, G., Leurs, R. & de Esch, T. J. P. (2008). J. Med. Chem. 51, 2457-2467.]); Tandon et al. (2006[Tandon, V. K., Yadav, D. B., Maurya, H. K., Chaturvedi, A. K. & Shukla, P. K. (2006). Bioorg. Med. Chem. Lett. 14, 6120-6126.]).

[Scheme 1]

Experimental

Crystal data
  • C13H14N2O3

  • Mr = 246.26

  • Monoclinic, P 21 /n

  • a = 8.3138 (6) Å

  • b = 13.6868 (8) Å

  • c = 10.8189 (8) Å

  • β = 102.002 (3)°

  • V = 1204.16 (14) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 296 K

  • 0.37 × 0.29 × 0.23 mm

Data collection
  • Bruker Kappa APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2007[Bruker (2007). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.965, Tmax = 0.978

  • 11123 measured reflections

  • 2938 independent reflections

  • 1370 reflections with I > 2σ(I)

  • Rint = 0.060

Refinement
  • R[F2 > 2σ(F2)] = 0.068

  • wR(F2) = 0.216

  • S = 0.96

  • 2938 reflections

  • 167 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.44 e Å−3

  • Δρmin = −0.30 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1N⋯O1i 0.96 (6) 1.87 (6) 2.827 (3) 179 (5)
C3—H3⋯O3ii 0.93 2.51 3.426 (4) 170
Symmetry codes: (i) -x+1, -y+1, -z; (ii) -x+1, -y+2, -z.

Data collection: APEX2 (Bruker, 2007[Bruker (2007). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). SADABS, APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]) and PLATON.

Supporting information


Comment top

Benzopyrazine constitute an important class of nitrogen containing heterocyclic compounds. Literature has shown that these compounds possess a vide variety of applications from pharmaceutical to agricultural fields. Several benzopyrazines have been reported as anti-bacterial (Sona et al., 1998), anti-convulsant(Cai et al., 1997), anti-cancer (Toshima et al., 2003), antidiabetic(Benbow et al., 2007), antidepressant(Sarges et al., 1990), antifungal(Tandon et al., 2006), anti-inflammatory (Smits et al., 2008), etc. The present work is based on the synthesis of pyrazines derivatives which may possess enhanced pharmaceutical activities.

The title compound (I) is structurally looks like planer but the dihedral angle between the two fused rings i.e. aromatic ring (C1/C2/C3/C4/C5/C6) and pyrazine ring (C1/C6/N1/N2/C7/C8) is 1.46 (11)%. The planer ester moiety attached to the C8 is oriented at dihedral angle of 5.70 (14)% and 7.13 (13)% with respect to the aomatic and pyrazine rings respectively. The cyclic carboxamide functional group from the pyrazine rings forms dimers through N—H···O type hydrogen bonding interaction which further connects through weak C—H···O type hydrogen bonding interaction to form the polymeric chain along b axes (Fig. 2 Table 1).

Related literature top

For the synthesis, see: Taylor et al. (1965). For the biological activity of benzopyrazines, see: Sona et al. (1998); Cai et al. (1997); Toshima et al. (2003); Benbow et al. (2007); Sarges et al. (1990); Smits et al. (2008); Tandon et al. (2006).

Experimental top

To the suspension of 3-(3-oxo-3,4-dihydroquinoxalin-2-yl)propanoic acid (Taylor et al., 1965) (5 g, 0.023 mol) in absolute ethanol (100 ml) was added 3N H2SO4 (10 ml) and reaction mixture was refluxed for four hours. Solution was then concentrated under reduced pressure and neutralized with sodium bicarbonate solution to dissolve any unreacted acid. The precipitates were filtered under reduced pressure and washed with excess of water. The resulting ester was then recrystallized in absolute ethanol to yield colourless needles of (I). The product melted at 173-175 C (lit mp 160-162 C). (95% yield).

Refinement top

All the C—H H-atoms were positioned with idealized geometry with C—H = 0.93 Å , C—H = 0.96 Å and C—H = 0.97 Å and were refined using a riding model with Uiso(H) = 1.2 Ueq(C) for aromatic and methylene and Uiso(H) = 1.5Ueq(C) for methyl C atoms. The N—H H atom were located in difference map with C—H = 0.96 Å with Uiso(H) = 1.2 Ueq(N). The reflection (011) was omitted during refinement as it was obscured by the beam stop.

Structure description top

Benzopyrazine constitute an important class of nitrogen containing heterocyclic compounds. Literature has shown that these compounds possess a vide variety of applications from pharmaceutical to agricultural fields. Several benzopyrazines have been reported as anti-bacterial (Sona et al., 1998), anti-convulsant(Cai et al., 1997), anti-cancer (Toshima et al., 2003), antidiabetic(Benbow et al., 2007), antidepressant(Sarges et al., 1990), antifungal(Tandon et al., 2006), anti-inflammatory (Smits et al., 2008), etc. The present work is based on the synthesis of pyrazines derivatives which may possess enhanced pharmaceutical activities.

The title compound (I) is structurally looks like planer but the dihedral angle between the two fused rings i.e. aromatic ring (C1/C2/C3/C4/C5/C6) and pyrazine ring (C1/C6/N1/N2/C7/C8) is 1.46 (11)%. The planer ester moiety attached to the C8 is oriented at dihedral angle of 5.70 (14)% and 7.13 (13)% with respect to the aomatic and pyrazine rings respectively. The cyclic carboxamide functional group from the pyrazine rings forms dimers through N—H···O type hydrogen bonding interaction which further connects through weak C—H···O type hydrogen bonding interaction to form the polymeric chain along b axes (Fig. 2 Table 1).

For the synthesis, see: Taylor et al. (1965). For the biological activity of benzopyrazines, see: Sona et al. (1998); Cai et al. (1997); Toshima et al. (2003); Benbow et al. (2007); Sarges et al. (1990); Smits et al. (2008); Tandon et al. (2006).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The structure of (I) with displacement ellipsoids drawn at the 50% probability level.
[Figure 2] Fig. 2. Unit cell packing diagram showing the hydrogen bonding using dashed lines, the hydrogen atoms not involved in hydrogen bonding have been omitted.
Ethyl 3-(3-oxo-3,4-dihydroquinoxalin-2-yl)propanoate top
Crystal data top
C13H14N2O3F(000) = 520
Mr = 246.26Dx = 1.358 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 1697 reflections
a = 8.3138 (6) Åθ = 2.8–24.6°
b = 13.6868 (8) ŵ = 0.10 mm1
c = 10.8189 (8) ÅT = 296 K
β = 102.002 (3)°Cut needle, colourless
V = 1204.16 (14) Å30.37 × 0.29 × 0.23 mm
Z = 4
Data collection top
Bruker Kappa APEXII CCD
diffractometer
2938 independent reflections
Radiation source: fine-focus sealed tube1370 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.060
φ and ω scansθmax = 28.3°, θmin = 3.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2007)
h = 1111
Tmin = 0.965, Tmax = 0.978k = 1118
11123 measured reflectionsl = 1414
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.068Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.216H atoms treated by a mixture of independent and constrained refinement
S = 0.96 w = 1/[σ2(Fo2) + (0.0982P)2 + 0.5331P]
where P = (Fo2 + 2Fc2)/3
2938 reflections(Δ/σ)max < 0.001
167 parametersΔρmax = 0.44 e Å3
0 restraintsΔρmin = 0.30 e Å3
Crystal data top
C13H14N2O3V = 1204.16 (14) Å3
Mr = 246.26Z = 4
Monoclinic, P21/nMo Kα radiation
a = 8.3138 (6) ŵ = 0.10 mm1
b = 13.6868 (8) ÅT = 296 K
c = 10.8189 (8) Å0.37 × 0.29 × 0.23 mm
β = 102.002 (3)°
Data collection top
Bruker Kappa APEXII CCD
diffractometer
2938 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2007)
1370 reflections with I > 2σ(I)
Tmin = 0.965, Tmax = 0.978Rint = 0.060
11123 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0680 restraints
wR(F2) = 0.216H atoms treated by a mixture of independent and constrained refinement
S = 0.96Δρmax = 0.44 e Å3
2938 reflectionsΔρmin = 0.30 e Å3
167 parameters
Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
xyzUiso*/Ueq
N20.5708 (3)0.81339 (16)0.0220 (2)0.0448 (6)
C60.3369 (3)0.70659 (19)0.0524 (3)0.0427 (7)
C10.4043 (3)0.79969 (19)0.0334 (3)0.0436 (7)
C80.6615 (3)0.73747 (19)0.0532 (3)0.0423 (7)
C50.1719 (4)0.6942 (2)0.1080 (3)0.0534 (8)
H50.12710.63180.11990.064*
N10.4382 (3)0.62700 (17)0.0166 (2)0.0478 (7)
O31.1357 (2)0.94521 (16)0.1990 (3)0.0763 (8)
C70.5997 (3)0.63615 (19)0.0353 (3)0.0448 (7)
C20.3048 (3)0.8807 (2)0.0717 (3)0.0518 (8)
H20.34870.94330.06000.062*
C90.8402 (3)0.7474 (2)0.1117 (3)0.0485 (8)
H9A0.90340.71370.05890.058*
H9B0.86130.71510.19330.058*
C100.9003 (3)0.8516 (2)0.1298 (3)0.0503 (8)
H10A0.88630.88340.04810.060*
H10B0.83480.88680.17970.060*
O10.6900 (2)0.56381 (14)0.0636 (2)0.0593 (7)
C111.0773 (4)0.8557 (2)0.1947 (3)0.0563 (9)
O21.1589 (3)0.78799 (19)0.2404 (3)0.0934 (10)
C30.1417 (4)0.8677 (2)0.1268 (3)0.0591 (9)
H30.07540.92190.15180.071*
C121.3079 (4)0.9554 (3)0.2601 (4)0.0911 (14)
H12A1.32710.92490.34280.109*
H12B1.37600.92260.21020.109*
C40.0752 (4)0.7746 (2)0.1455 (3)0.0577 (9)
H40.03510.76670.18340.069*
C131.3500 (6)1.0526 (4)0.2726 (6)0.131 (2)
H13C1.34101.08110.19040.196*
H13A1.46111.05870.31930.196*
H13B1.27731.08580.31690.196*
H1N0.394 (6)0.562 (5)0.033 (5)0.157*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N20.0344 (13)0.0382 (13)0.0576 (16)0.0021 (10)0.0004 (11)0.0004 (11)
C60.0340 (15)0.0374 (15)0.0542 (18)0.0006 (12)0.0034 (13)0.0025 (13)
C10.0362 (16)0.0384 (16)0.0526 (18)0.0021 (12)0.0010 (13)0.0010 (13)
C80.0357 (15)0.0362 (15)0.0507 (17)0.0023 (11)0.0009 (13)0.0001 (13)
C50.0374 (17)0.0458 (18)0.073 (2)0.0046 (13)0.0014 (15)0.0021 (15)
N10.0332 (13)0.0357 (13)0.0680 (17)0.0008 (10)0.0049 (11)0.0009 (11)
O30.0340 (12)0.0536 (14)0.127 (2)0.0050 (10)0.0155 (12)0.0091 (14)
C70.0396 (16)0.0347 (15)0.0564 (19)0.0002 (12)0.0015 (14)0.0025 (13)
C20.0428 (18)0.0371 (16)0.071 (2)0.0018 (12)0.0008 (15)0.0003 (14)
C90.0339 (16)0.0423 (16)0.065 (2)0.0019 (12)0.0004 (14)0.0012 (14)
C100.0336 (16)0.0424 (17)0.069 (2)0.0006 (12)0.0035 (14)0.0018 (15)
O10.0428 (12)0.0353 (11)0.0905 (17)0.0076 (9)0.0075 (11)0.0010 (10)
C110.0356 (16)0.052 (2)0.074 (2)0.0011 (14)0.0057 (15)0.0044 (16)
O20.0467 (15)0.0687 (17)0.143 (3)0.0075 (12)0.0295 (15)0.0194 (16)
C30.0420 (18)0.0458 (18)0.083 (2)0.0102 (14)0.0017 (16)0.0066 (16)
C120.038 (2)0.081 (3)0.138 (4)0.0081 (18)0.020 (2)0.014 (3)
C40.0324 (16)0.055 (2)0.081 (2)0.0031 (13)0.0010 (15)0.0037 (17)
C130.078 (3)0.088 (4)0.207 (6)0.031 (3)0.015 (3)0.020 (4)
Geometric parameters (Å, º) top
N2—C81.287 (3)C9—C101.511 (4)
N2—C11.402 (3)C9—H9A0.9700
C6—N11.382 (3)C9—H9B0.9700
C6—C51.389 (4)C10—C111.494 (4)
C6—C11.390 (4)C10—H10A0.9700
C1—C21.394 (4)C10—H10B0.9700
C8—C71.478 (4)C11—O21.193 (4)
C8—C91.495 (4)C3—C41.387 (4)
C5—C41.373 (4)C3—H30.9300
C5—H50.9300C12—C131.375 (6)
N1—C71.349 (3)C12—H12A0.9700
N1—H1N0.96 (6)C12—H12B0.9700
O3—C111.316 (4)C4—H40.9300
O3—C121.453 (4)C13—H13C0.9600
C7—O11.242 (3)C13—H13A0.9600
C2—C31.375 (4)C13—H13B0.9600
C2—H20.9300
C8—N2—C1118.5 (2)H9A—C9—H9B107.6
N1—C6—C5121.0 (2)C11—C10—C9111.3 (2)
N1—C6—C1118.5 (2)C11—C10—H10A109.4
C5—C6—C1120.5 (3)C9—C10—H10A109.4
C6—C1—C2119.3 (3)C11—C10—H10B109.4
C6—C1—N2121.2 (2)C9—C10—H10B109.4
C2—C1—N2119.5 (2)H10A—C10—H10B108.0
N2—C8—C7123.6 (3)O2—C11—O3122.4 (3)
N2—C8—C9121.0 (2)O2—C11—C10125.8 (3)
C7—C8—C9115.4 (2)O3—C11—C10111.8 (3)
C4—C5—C6119.7 (3)C2—C3—C4120.6 (3)
C4—C5—H5120.2C2—C3—H3119.7
C6—C5—H5120.2C4—C3—H3119.7
C7—N1—C6122.6 (2)C13—C12—O3110.1 (4)
C7—N1—H1N118 (3)C13—C12—H12A109.6
C6—N1—H1N119 (3)O3—C12—H12A109.6
C11—O3—C12115.2 (3)C13—C12—H12B109.6
O1—C7—N1121.8 (2)O3—C12—H12B109.6
O1—C7—C8122.7 (3)H12A—C12—H12B108.2
N1—C7—C8115.5 (2)C5—C4—C3120.1 (3)
C3—C2—C1119.8 (3)C5—C4—H4119.9
C3—C2—H2120.1C3—C4—H4119.9
C1—C2—H2120.1C12—C13—H13C109.5
C8—C9—C10114.4 (2)C12—C13—H13A109.5
C8—C9—H9A108.7H13C—C13—H13A109.5
C10—C9—H9A108.7C12—C13—H13B109.5
C8—C9—H9B108.7H13C—C13—H13B109.5
C10—C9—H9B108.7H13A—C13—H13B109.5
N1—C6—C1—C2178.5 (3)N2—C8—C7—N10.2 (4)
C5—C6—C1—C20.4 (5)C9—C8—C7—N1179.5 (3)
N1—C6—C1—N20.8 (4)C6—C1—C2—C30.4 (5)
C5—C6—C1—N2179.7 (3)N2—C1—C2—C3179.6 (3)
C8—N2—C1—C61.3 (4)N2—C8—C9—C100.1 (4)
C8—N2—C1—C2177.9 (3)C7—C8—C9—C10179.6 (3)
C1—N2—C8—C70.8 (4)C8—C9—C10—C11177.0 (3)
C1—N2—C8—C9179.5 (3)C12—O3—C11—O21.7 (5)
N1—C6—C5—C4178.4 (3)C12—O3—C11—C10179.6 (3)
C1—C6—C5—C40.5 (5)C9—C10—C11—O28.1 (5)
C5—C6—N1—C7178.6 (3)C9—C10—C11—O3173.2 (3)
C1—C6—N1—C70.3 (4)C1—C2—C3—C40.4 (5)
C6—N1—C7—O1177.9 (3)C11—O3—C12—C13172.8 (4)
C6—N1—C7—C80.8 (4)C6—C5—C4—C30.5 (5)
N2—C8—C7—O1178.5 (3)C2—C3—C4—C50.5 (5)
C9—C8—C7—O11.8 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N···O1i0.96 (6)1.87 (6)2.827 (3)179 (5)
C3—H3···O3ii0.932.513.426 (4)170
Symmetry codes: (i) x+1, y+1, z; (ii) x+1, y+2, z.

Experimental details

Crystal data
Chemical formulaC13H14N2O3
Mr246.26
Crystal system, space groupMonoclinic, P21/n
Temperature (K)296
a, b, c (Å)8.3138 (6), 13.6868 (8), 10.8189 (8)
β (°) 102.002 (3)
V3)1204.16 (14)
Z4
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.37 × 0.29 × 0.23
Data collection
DiffractometerBruker Kappa APEXII CCD
Absorption correctionMulti-scan
(SADABS; Bruker, 2007)
Tmin, Tmax0.965, 0.978
No. of measured, independent and
observed [I > 2σ(I)] reflections
11123, 2938, 1370
Rint0.060
(sin θ/λ)max1)0.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.068, 0.216, 0.96
No. of reflections2938
No. of parameters167
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.44, 0.30

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009), WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N···O1i0.96 (6)1.87 (6)2.827 (3)179 (5)
C3—H3···O3ii0.932.513.426 (4)170
Symmetry codes: (i) x+1, y+1, z; (ii) x+1, y+2, z.
 

Acknowledgements

The authors are grateful to the HEC (Higher Education Commission of Pakistan) for the financial support of this work.

References

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