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

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ISSN: 2056-9890

2,10-Bis(3-bromo­phen­yl)-3,7,11,15-tetra­oxa-8,16-di­aza­tri­cyclo­[12.2.1.16,9]octa­deca-1(16),6(18),8,14(17)-tetra­ene

aSchool of Applied Chemical Engineering, Chonnam National University, Gwangju 500-757, Republic of Korea, and bGwangju Branch, Korea Basic Science Institute, Gwangju 500-757, Republic of Korea
*Correspondence e-mail: hyungkim@chonnam.ac.kr

(Received 19 July 2010; accepted 19 July 2010; online 24 July 2010)

The title compound, C24H20Br2N2O4, is an 18-membered tricycle including two isoxazole rings. The asymmetric unit contains one half of the formula unit; a centre of inversion is located at the centroid of the compound. The dihedral angle between adjacent isoxazole and benzene rings is 84.0 (2)°. The compound displays intra- and inter­molecular ππ stacking inter­actions between the isoxazole rings, the shortest centroid–centroid distances being 3.837 (3) and 3.634 (3) Å, respectively. The mol­ecules are stacked in columns along the a axis with short Br⋯Br contacts [3.508 (1) Å].

Related literature

For the biological activity of isoxazole derivatives, see: Kim et al. (1994[Kim, H. J., Hwang, K.-J. & Lee, J. H. (1994). Biosci. Biotechnol. Biochem. 58, 1191-1192.], 1997[Kim, H. J., Hwang, K.-J. & Lee, J. H. (1997). Bull. Korean Chem. Soc. 18, 534-540.]); Lang & Lin (1984[Lang, A. & Lin, Y. (1984). Comprehensive Heterocyclic Chemistry, Vol. 6, edited by A. R. Katritzky, pp. 1-130. Oxford: Pergamon Press.]). For the syntheses of various pyrano[3,4-c]isoxzole derivatives, see: Kim et al. (1999[Kim, H. J., Jang, J. Y., Chung, K. H. & Lee, J. H. (1999). Biosci. Biotechnol. Biochem. 63, 494-499.]).

[Scheme 1]

Experimental

Crystal data
  • C24H20Br2N2O4

  • Mr = 560.24

  • Triclinic, [P \overline 1]

  • a = 5.6446 (4) Å

  • b = 7.3703 (5) Å

  • c = 13.701 (1) Å

  • α = 93.735 (1)°

  • β = 99.564 (1)°

  • γ = 102.363 (1)°

  • V = 546.03 (7) Å3

  • Z = 1

  • Mo Kα radiation

  • μ = 3.75 mm−1

  • T = 200 K

  • 0.34 × 0.26 × 0.17 mm

Data collection
  • Bruker SMART 1000 CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2000[Bruker (2000). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.797, Tmax = 1.000

  • 4051 measured reflections

  • 2645 independent reflections

  • 2040 reflections with I > 2σ(I)

  • Rint = 0.015

Refinement
  • R[F2 > 2σ(F2)] = 0.046

  • wR(F2) = 0.152

  • S = 1.30

  • 2645 reflections

  • 145 parameters

  • H-atom parameters constrained

  • Δρmax = 1.25 e Å−3

  • Δρmin = −1.87 e Å−3

Data collection: SMART (Bruker, 2000[Bruker (2000). SADABS, SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2000[Bruker (2000). SADABS, SMART 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: SHELXL97.

Supporting information


Comment top

Many isoxazole derivatives are known to have a variety of biological activities in pharmaceutical and agricultural areas (Kim et al., 1994, 1997; Lang & Lin, 1984). Recently we reported that the syntheses of various pyrano[3,4-c]isoxzole derivatives by means of the intramolecular 1,3-dipolar cycloaddition of a nitrile oxide containing an alkyne moiety within the structure and that these fused isoxazoles displayed fungicidal activities against some plant pathogens (Kim et al., 1999). During the chromatographic purification of the crude product, we isolated an unexpected macrocylic isoxazole compound which was formed by intermolecular cycloaddition process.

The asymmetric unit of the title compound, C24H20Br2N2O4, contains one half of the formula unit; a centre of inversion is located at the midpoint of the compound (Fig. 1). The C7 and C11 atoms lie in the isoxazole ring plane with the largest deviation of 0.055 (9) Å (C7) from the least-squares plane of the isoxazole ring. The compound displays intra- and intermolecular π-π interactions between the isoxazole rings (the symmetry operations for second planes: -x,-y,-z and -x,1 - y,-z, respectively), the shortest centroid-centroid distance being 3.837 (3) Å and 3.634 (3) Å, respectively. The parallel planes are shifted for 1.048 Å and 1.936 Å, respectively (Fig. 2). There may also be weak intermolecular π-π interactions between adjacent benzene rings, with a shortest centroid-centroid distance of 4.453 (4) Å. The molecules are stacked in columns along the a axis and the Br···Br contacts are present. The shortest Br1···Br1a [symmetry code: (a) 2 - x,-y,1 - z] distance is 3.508 (1) Å.

Related literature top

For the biological activity of isoxazole derivatives, see: Kim et al. (1994, 1997); Lang & Lin (1984). For the syntheses of various pyrano[3,4-c]isoxzole derivatives, see: Kim et al. (1999).

Experimental top

A mixture of 1-bromo-3-[1-(but-3-ynyloxy)-2-nitroethyl]benzene (1.49 g, 5 mmol), phenyl isocyanate (2.97 g, 25 mmol) and Et3N (51 mg, 0.5 mmol) in dry benzene (30 ml) was stirred for 12 h at 25 °C under nitrogen atmosphere. Water (1 ml) was added and the mixture was stirred for 2 h at which time the solids were removed by vacuum filtration. The filtrate was dried (MgSO4) and concentrated in vacuo to give crude product, which was column chromatographed (SiO2) by eluting with a mixture of n-hexane/EtOAc (10:1) to afford the title compound (34 mg, 1.2%) as a white solid. Crystals suitable for X-ray analysis were obtained by slow evaporation from an n-hexane/EtOAc solution. Mp 231 °C. 1H NMR (600 MHz, CDCl3): δ 7.57 (s, 2H, Ar), 7.41–7.18 (m, 6H, Ar), 5.41 (s, 2H, isoxazole), 5.37 (s, 2H, –O—CH-C6H4Br), 4.19 (dt, 2H, J = 10.2 Hz, 3.0 Hz, –CH2CHH—O), 3.67 (bt, 2H, J = 10.2 Hz, –CH2CHH-O–), 3.15 (ddd, 2H, J = 16.2 Hz, 12.6 Hz, 3.0 Hz, –CHH—CH2O–), 2.77 (bd, J = 16.2 Hz, –CHH-CH2O–). 13C NMR (150 MHz, CDCl3): δ 172.71, 164.13, 141.11, 131.00, 129.98, 128.74, 124.43, 122.61, 98.90, 74.22, 67.40, 27.91.

Refinement top

H atoms were positioned geometrically and allowed to ride on their respective parent atoms [C—H = 0.95 (CH, sp2), 1.00 (CH, sp3) or 0.99 Å (CH2) and Uiso(H) = 1.2Ueq(C)]. The highest peak (1.25 e Å-3) and the deepest hole (-1.87 e Å-3) in the difference Fourier map are located 1.46 Å and 0.89 Å from the Br1 atom, respectively.

Structure description top

Many isoxazole derivatives are known to have a variety of biological activities in pharmaceutical and agricultural areas (Kim et al., 1994, 1997; Lang & Lin, 1984). Recently we reported that the syntheses of various pyrano[3,4-c]isoxzole derivatives by means of the intramolecular 1,3-dipolar cycloaddition of a nitrile oxide containing an alkyne moiety within the structure and that these fused isoxazoles displayed fungicidal activities against some plant pathogens (Kim et al., 1999). During the chromatographic purification of the crude product, we isolated an unexpected macrocylic isoxazole compound which was formed by intermolecular cycloaddition process.

The asymmetric unit of the title compound, C24H20Br2N2O4, contains one half of the formula unit; a centre of inversion is located at the midpoint of the compound (Fig. 1). The C7 and C11 atoms lie in the isoxazole ring plane with the largest deviation of 0.055 (9) Å (C7) from the least-squares plane of the isoxazole ring. The compound displays intra- and intermolecular π-π interactions between the isoxazole rings (the symmetry operations for second planes: -x,-y,-z and -x,1 - y,-z, respectively), the shortest centroid-centroid distance being 3.837 (3) Å and 3.634 (3) Å, respectively. The parallel planes are shifted for 1.048 Å and 1.936 Å, respectively (Fig. 2). There may also be weak intermolecular π-π interactions between adjacent benzene rings, with a shortest centroid-centroid distance of 4.453 (4) Å. The molecules are stacked in columns along the a axis and the Br···Br contacts are present. The shortest Br1···Br1a [symmetry code: (a) 2 - x,-y,1 - z] distance is 3.508 (1) Å.

For the biological activity of isoxazole derivatives, see: Kim et al. (1994, 1997); Lang & Lin (1984). For the syntheses of various pyrano[3,4-c]isoxzole derivatives, see: Kim et al. (1999).

Computing details top

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: ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The structure of the title compound, with displacement ellipsoids drawn at the 50% probability level for non-H atoms [Symmetry code: (i) -x, -y, -z].
[Figure 2] Fig. 2. View of the unit-cell contents of the title compound.
2,10-Bis(3-bromophenyl)-3,7,11,15-tetraoxa-8,16- diazatricyclo[12.2.1.16,9]octadeca-1(16),6(18),8,14 (17)-tetraene top
Crystal data top
C24H20Br2N2O4Z = 1
Mr = 560.24F(000) = 280
Triclinic, P1Dx = 1.704 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 5.6446 (4) ÅCell parameters from 2388 reflections
b = 7.3703 (5) Åθ = 2.8–28.1°
c = 13.701 (1) ŵ = 3.75 mm1
α = 93.735 (1)°T = 200 K
β = 99.564 (1)°Plate, colorless
γ = 102.363 (1)°0.34 × 0.26 × 0.17 mm
V = 546.03 (7) Å3
Data collection top
Bruker SMART 1000 CCD
diffractometer
2645 independent reflections
Radiation source: fine-focus sealed tube2040 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.015
φ and ω scansθmax = 28.3°, θmin = 2.8°
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
h = 76
Tmin = 0.797, Tmax = 1.000k = 99
4051 measured reflectionsl = 1618
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)] = 0.046Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.152H-atom parameters constrained
S = 1.30 w = 1/[σ2(Fo2) + (0.P)2 + 3.5324P]
where P = (Fo2 + 2Fc2)/3
2645 reflections(Δ/σ)max < 0.001
145 parametersΔρmax = 1.25 e Å3
0 restraintsΔρmin = 1.87 e Å3
Crystal data top
C24H20Br2N2O4γ = 102.363 (1)°
Mr = 560.24V = 546.03 (7) Å3
Triclinic, P1Z = 1
a = 5.6446 (4) ÅMo Kα radiation
b = 7.3703 (5) ŵ = 3.75 mm1
c = 13.701 (1) ÅT = 200 K
α = 93.735 (1)°0.34 × 0.26 × 0.17 mm
β = 99.564 (1)°
Data collection top
Bruker SMART 1000 CCD
diffractometer
2645 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2000)
2040 reflections with I > 2σ(I)
Tmin = 0.797, Tmax = 1.000Rint = 0.015
4051 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0460 restraints
wR(F2) = 0.152H-atom parameters constrained
S = 1.30Δρmax = 1.25 e Å3
2645 reflectionsΔρmin = 1.87 e Å3
145 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
xyzUiso*/Ueq
Br10.78777 (12)0.13416 (10)0.45968 (6)0.0464 (2)
O10.0873 (7)0.2957 (6)0.0511 (3)0.0304 (9)
O20.0557 (7)0.0026 (5)0.2100 (3)0.0323 (9)
N10.1737 (8)0.2688 (7)0.0394 (4)0.0315 (10)
C10.5786 (11)0.2773 (8)0.3908 (4)0.0336 (12)
C20.3670 (11)0.1843 (8)0.3295 (4)0.0333 (12)
H20.32260.05170.32160.040*
C30.2166 (10)0.2874 (8)0.2784 (4)0.0288 (11)
C40.2855 (12)0.4808 (8)0.2927 (5)0.0383 (14)
H40.18270.55210.25880.046*
C50.5037 (13)0.5714 (9)0.3561 (5)0.0443 (16)
H50.54930.70400.36550.053*
C60.6540 (12)0.4683 (9)0.4054 (5)0.0411 (15)
H60.80490.52780.44820.049*
C70.0170 (10)0.1934 (7)0.2048 (4)0.0286 (11)
H70.16060.23850.22290.034*
C80.0115 (9)0.2363 (7)0.1015 (4)0.0254 (11)
C90.2206 (10)0.2402 (7)0.0570 (4)0.0273 (11)
H90.37640.22080.08670.033*
C100.1503 (9)0.2772 (7)0.0368 (4)0.0263 (11)
C110.2785 (10)0.2954 (8)0.1230 (4)0.0303 (12)
H11A0.44540.37740.10160.036*
H11B0.18570.35390.17490.036*
C120.2998 (10)0.1054 (8)0.1658 (4)0.0310 (12)
H12A0.37290.03850.11250.037*
H12B0.40660.12010.21660.037*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0331 (3)0.0454 (4)0.0559 (4)0.0092 (3)0.0055 (3)0.0045 (3)
O10.0248 (19)0.038 (2)0.031 (2)0.0108 (16)0.0029 (16)0.0109 (17)
O20.029 (2)0.029 (2)0.032 (2)0.0001 (16)0.0033 (16)0.0014 (16)
N10.023 (2)0.040 (3)0.032 (3)0.008 (2)0.0034 (19)0.005 (2)
C10.034 (3)0.034 (3)0.033 (3)0.011 (2)0.005 (2)0.006 (2)
C20.035 (3)0.027 (3)0.035 (3)0.002 (2)0.009 (2)0.006 (2)
C30.031 (3)0.026 (3)0.027 (3)0.004 (2)0.003 (2)0.003 (2)
C40.042 (3)0.029 (3)0.038 (3)0.007 (3)0.006 (3)0.002 (3)
C50.052 (4)0.026 (3)0.042 (4)0.004 (3)0.008 (3)0.000 (3)
C60.033 (3)0.044 (4)0.035 (3)0.008 (3)0.004 (3)0.002 (3)
C70.028 (3)0.025 (3)0.031 (3)0.006 (2)0.003 (2)0.000 (2)
C80.025 (3)0.022 (2)0.030 (3)0.007 (2)0.002 (2)0.002 (2)
C90.022 (2)0.026 (3)0.034 (3)0.005 (2)0.002 (2)0.004 (2)
C100.022 (2)0.022 (2)0.032 (3)0.0018 (19)0.002 (2)0.004 (2)
C110.029 (3)0.027 (3)0.032 (3)0.002 (2)0.005 (2)0.004 (2)
C120.023 (3)0.031 (3)0.038 (3)0.003 (2)0.005 (2)0.007 (2)
Geometric parameters (Å, º) top
Br1—C11.921 (6)C5—H50.9500
O1—C101.360 (6)C6—H60.9500
O1—N11.416 (6)C7—C81.497 (8)
O2—C71.423 (6)C7—H71.0000
O2—C121.433 (6)C8—C91.412 (7)
N1—C81.308 (7)C9—C101.344 (7)
C1—C21.358 (8)C9—H90.9500
C1—C61.372 (9)C10—C111.483 (8)
C2—C31.391 (8)C11—C12i1.520 (8)
C2—H20.9500C11—H11A0.9900
C3—C41.386 (8)C11—H11B0.9900
C3—C71.521 (7)C12—C11i1.520 (8)
C4—C51.391 (8)C12—H12A0.9900
C4—H40.9500C12—H12B0.9900
C5—C61.381 (9)
C10—O1—N1107.8 (4)O2—C7—H7109.7
C7—O2—C12114.0 (4)C8—C7—H7109.7
C8—N1—O1105.5 (4)C3—C7—H7109.7
C2—C1—C6123.7 (6)N1—C8—C9111.9 (5)
C2—C1—Br1118.4 (5)N1—C8—C7120.4 (5)
C6—C1—Br1117.9 (5)C9—C8—C7127.6 (5)
C1—C2—C3118.6 (5)C10—C9—C8104.7 (5)
C1—C2—H2120.7C10—C9—H9127.6
C3—C2—H2120.7C8—C9—H9127.6
C4—C3—C2119.1 (5)C9—C10—O1110.0 (5)
C4—C3—C7119.1 (5)C9—C10—C11132.4 (5)
C2—C3—C7121.7 (5)O1—C10—C11117.5 (5)
C3—C4—C5120.7 (6)C10—C11—C12i110.7 (5)
C3—C4—H4119.6C10—C11—H11A109.5
C5—C4—H4119.6C12i—C11—H11A109.5
C6—C5—C4119.8 (6)C10—C11—H11B109.5
C6—C5—H5120.1C12i—C11—H11B109.5
C4—C5—H5120.1H11A—C11—H11B108.1
C1—C6—C5118.0 (6)O2—C12—C11i107.4 (4)
C1—C6—H6121.0O2—C12—H12A110.2
C5—C6—H6121.0C11i—C12—H12A110.2
O2—C7—C8109.7 (4)O2—C12—H12B110.2
O2—C7—C3107.8 (4)C11i—C12—H12B110.2
C8—C7—C3110.1 (5)H12A—C12—H12B108.5
C10—O1—N1—C80.0 (6)C2—C3—C7—C8113.0 (6)
C6—C1—C2—C30.1 (10)O1—N1—C8—C90.0 (6)
Br1—C1—C2—C3179.2 (4)O1—N1—C8—C7177.6 (4)
C1—C2—C3—C40.8 (9)O2—C7—C8—N1100.4 (6)
C1—C2—C3—C7177.1 (6)C3—C7—C8—N1141.0 (5)
C2—C3—C4—C50.8 (10)O2—C7—C8—C976.8 (7)
C7—C3—C4—C5177.1 (6)C3—C7—C8—C941.8 (7)
C3—C4—C5—C60.1 (11)N1—C8—C9—C100.0 (6)
C2—C1—C6—C51.1 (10)C7—C8—C9—C10177.4 (5)
Br1—C1—C6—C5179.9 (5)C8—C9—C10—O10.0 (6)
C4—C5—C6—C11.0 (11)C8—C9—C10—C11178.2 (5)
C12—O2—C7—C876.1 (6)N1—O1—C10—C90.0 (6)
C12—O2—C7—C3164.0 (5)N1—O1—C10—C11178.6 (4)
C4—C3—C7—O2175.5 (5)C9—C10—C11—C12i73.1 (7)
C2—C3—C7—O26.6 (7)O1—C10—C11—C12i105.0 (5)
C4—C3—C7—C864.8 (7)C7—O2—C12—C11i147.7 (5)
Symmetry code: (i) x, y, z.

Experimental details

Crystal data
Chemical formulaC24H20Br2N2O4
Mr560.24
Crystal system, space groupTriclinic, P1
Temperature (K)200
a, b, c (Å)5.6446 (4), 7.3703 (5), 13.701 (1)
α, β, γ (°)93.735 (1), 99.564 (1), 102.363 (1)
V3)546.03 (7)
Z1
Radiation typeMo Kα
µ (mm1)3.75
Crystal size (mm)0.34 × 0.26 × 0.17
Data collection
DiffractometerBruker SMART 1000 CCD
Absorption correctionMulti-scan
(SADABS; Bruker, 2000)
Tmin, Tmax0.797, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
4051, 2645, 2040
Rint0.015
(sin θ/λ)max1)0.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.046, 0.152, 1.30
No. of reflections2645
No. of parameters145
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)1.25, 1.87

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2009).

 

Acknowledgements

This study was supported financially by Chonnam National University, 2008.

References

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First citationKim, H. J., Jang, J. Y., Chung, K. H. & Lee, J. H. (1999). Biosci. Biotechnol. Biochem. 63, 494–499.  Web of Science CrossRef CAS Google Scholar
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