organic compounds
tert-Butyl 3-(8-bromo-4H,10H-1,2-oxazolo[4,3-c][1]benzoxepin-10-yl)-2-methyl-1H-indole-1-carboxylate
aCentre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India, and bCLRI, Adyar, Chennai 600 020, India
*Correspondence e-mail: gunaunom@gmail.com
In the title compound, C25H23BrN2O4, the seven-membered ring adopts a twisted-boat conformation. The indole ring system is planar within 0.021 (2) Å and the ester group [–C(=O)—O—C–] is almost coplanar with it [dihedral angle = 3.0 (2)°]. The conformation of the ester group is influenced by intramolecular C—H⋯O interactions. In the molecules are linked into chains along the b axis by C—H⋯N hydrogen bonds.
Related literature
For general background to and biological applications of nitrogen- and oxygen-containing ); Liddell (2002); Caramella & Grunanger (1984); Stormer et al. (2004); Erdelyi et al. (2008). Hou et al. (2003). For puckering parameters, see: Cremer & Pople (1975). For asymmetry parameters, see: Nardelli (1983).
see: Furstner (2003Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2008); cell SAINT (Bruker, 2008); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009).
Supporting information
https://doi.org/10.1107/S1600536810027297/ci5101sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810027297/ci5101Isup2.hkl
[3-(5-Bromo-2-prop-2-ynyloxy-phenyl)-2-nitro-ethyl]-2-methyl-1H-indole] (1.0 mmol) and N,N-dimethyl-4-aminopyridine (0.2 mmol) were dissolved in toluene (5 ml). Di-tert-butyl dicarbonate (2.5 mmol) in toluene (5 ml) was added in portions over a period of 0.5 h at 363 K to the nitroalkane solution and the reaction was allowed to proceed for a further 2 h. The mixture was evaporated and the product was purified by
using ethyl acetate-petroleum ether (2:8) as Single crystals appeared from the same mixture.H atoms were positioned geometrically (C–H = 0.93–0.98 Å) and allowed to ride on their parent atoms, with Uiso(H) = 1.5Ueq(C) for methyl H and 1.2Ueq(C) for other H atoms.
Nitrogen and oxygen containing heterocycles are ubiquitous substructures in myriad of biologically active natural products and small-molecule pharmaceuticals (Furstner, 2003; Liddell, 2002). The nitrile oxide γ-amino and β-hydroxy Isoxazoles are found in some natural products, such as ibotenic acid. Ibotenic acid is naturally occurring in mushrooms Amanita muscaria and Amanita pantherina. Ibotenic acid is a powerful neurotoxin that is used as a brain-lesioning agent and has shown to be highly neurotoxic when injected directly into the brains of mice and rats. Isoxazoles also form the basis for a number of drugs, including the COX-2 inhibitor valdecoxib. Valdecoxib is a prescription drug used in the treatment of osteoarthritis, rheumatoid arthritis, painful menstruation and menstrual symptoms (Stormer et al., 2004; Erdelyi et al., 2008).
is a useful method to prepare (Caramella & Grunanger, 1984). Isoxazole, the cycloadduct of nitrile oxide, is regarded as a versatile synthetic precursor forIn the title (Fig. 1), the indole ring system is planar within ±0.021 (2) Å. The oxepane ring adopts a twisted boat conformation with puckering parameters (Cremer & Pople, 1975) and asymmetry parameters (Nardelli, 1983) of q2 = 0.654 (3) Å, φ2 = 179.9 (3)°, q3 = 0.380 (3) Å, φ3 = 222.4 (3)° and Δs(C7) = 34.3 (3)°. The position of atom O2 which lies between bromobenzene and isooxazone rings is defined by torsion angles O2—C8—C7—C5 of -34.0 (4)° and O2—C9—C10—C11 of 176.4 (3)°.
The ester group [-C(═O)-O-C-] is coplanar with the indole ring system [dihedral angle 3.0 (2)°]. The planarity is facilitated by intramolecular C14—H14A···O3 C24—H24B···O3 hydrogen bonds (Table 1). A about the O4—C22 single bond [1.492 (3) Å] is restricted by the C24—H24B···O3 hydrogen bond. The angles around atom C4 [C12—C4—C3 = 113.6 (2)° and C5—C4—C3 = 115.6 (2)°] deviates significantly from ideal tetrahedral values which may be as a result of steric interactions between isooxazole, bromophenol and indole groups.
Atom C11 in the molecule at (x,y,z) acts as donar to atom N1 at (x, 1+y, z), forming a chain running along the b axis (Fig. 2).
For general background to and biological applications of nitrogen- and oxygen-containing
see: Furstner (2003); Liddell (2002); Caramella & Grunanger (1984); Stormer et al. (2004); Erdelyi et al. (2008). Hou et al. (2003). For puckering parameters, see: Cremer & Pople (1975). For asymmetry parameters, see: Nardelli (1983).Data collection: APEX2 (Bruker, 2008); cell
SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).C25H23BrN2O4 | F(000) = 1016 |
Mr = 495.36 | Dx = 1.461 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 1964 reflections |
a = 16.0494 (6) Å | θ = 1.4–28.4° |
b = 9.6497 (4) Å | µ = 1.86 mm−1 |
c = 16.2202 (7) Å | T = 293 K |
β = 116.267 (2)° | Block, colourless |
V = 2252.66 (16) Å3 | 0.20 × 0.20 × 0.20 mm |
Z = 4 |
Bruker SMART APEXII area-detector diffractometer | 5584 independent reflections |
Radiation source: fine-focus sealed tube | 2780 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.049 |
ω and φ scans | θmax = 28.4°, θmin = 1.4° |
Absorption correction: multi-scan (SADABS; Bruker, 2008) | h = −21→21 |
Tmin = 0.982, Tmax = 0.982 | k = −12→12 |
20668 measured reflections | l = −21→17 |
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)] = 0.046 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.134 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0504P)2 + 1.2404P] where P = (Fo2 + 2Fc2)/3 |
5584 reflections | (Δ/σ)max = 0.002 |
289 parameters | Δρmax = 0.40 e Å−3 |
1 restraint | Δρmin = −0.48 e Å−3 |
C25H23BrN2O4 | V = 2252.66 (16) Å3 |
Mr = 495.36 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 16.0494 (6) Å | µ = 1.86 mm−1 |
b = 9.6497 (4) Å | T = 293 K |
c = 16.2202 (7) Å | 0.20 × 0.20 × 0.20 mm |
β = 116.267 (2)° |
Bruker SMART APEXII area-detector diffractometer | 5584 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2008) | 2780 reflections with I > 2σ(I) |
Tmin = 0.982, Tmax = 0.982 | Rint = 0.049 |
20668 measured reflections |
R[F2 > 2σ(F2)] = 0.046 | 1 restraint |
wR(F2) = 0.134 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.40 e Å−3 |
5584 reflections | Δρmin = −0.48 e Å−3 |
289 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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. |
x | y | z | Uiso*/Ueq | ||
Br1 | 0.21016 (4) | 0.94661 (4) | 0.20807 (3) | 0.0911 (2) | |
O1 | 0.48628 (16) | 0.2154 (2) | 0.14770 (17) | 0.0662 (7) | |
O2 | 0.43563 (16) | 0.6581 (2) | 0.04692 (15) | 0.0590 (6) | |
O3 | −0.01565 (17) | 0.2636 (3) | 0.02194 (17) | 0.0791 (8) | |
O4 | 0.02421 (14) | 0.2088 (2) | 0.16886 (14) | 0.0513 (5) | |
N1 | 0.40074 (18) | 0.2682 (3) | 0.1374 (2) | 0.0543 (7) | |
N2 | 0.12827 (16) | 0.3153 (2) | 0.13481 (16) | 0.0389 (6) | |
C1 | 0.2807 (2) | 0.8543 (3) | 0.1577 (2) | 0.0550 (8) | |
C2 | 0.2779 (2) | 0.7113 (3) | 0.1518 (2) | 0.0476 (8) | |
H2 | 0.2406 | 0.6620 | 0.1719 | 0.057* | |
C3 | 0.3299 (2) | 0.6404 (3) | 0.1163 (2) | 0.0424 (7) | |
C4 | 0.3153 (2) | 0.4858 (3) | 0.0952 (2) | 0.0429 (7) | |
H4 | 0.2828 | 0.4793 | 0.0280 | 0.051* | |
C5 | 0.4033 (2) | 0.4004 (3) | 0.1233 (2) | 0.0425 (7) | |
C6 | 0.5349 (2) | 0.3220 (4) | 0.1381 (2) | 0.0584 (9) | |
H6 | 0.5940 | 0.3139 | 0.1411 | 0.070* | |
C7 | 0.4885 (2) | 0.4401 (3) | 0.1237 (2) | 0.0462 (8) | |
C8 | 0.5156 (2) | 0.5831 (4) | 0.1103 (3) | 0.0598 (9) | |
H8A | 0.5432 | 0.6312 | 0.1689 | 0.072* | |
H8B | 0.5615 | 0.5784 | 0.0868 | 0.072* | |
C9 | 0.3850 (2) | 0.7190 (3) | 0.0876 (2) | 0.0468 (7) | |
C10 | 0.3868 (2) | 0.8620 (4) | 0.0935 (2) | 0.0605 (9) | |
H10 | 0.4241 | 0.9122 | 0.0736 | 0.073* | |
C11 | 0.3343 (3) | 0.9314 (3) | 0.1283 (3) | 0.0635 (10) | |
H11 | 0.3351 | 1.0276 | 0.1318 | 0.076* | |
C14 | 0.1088 (2) | 0.3832 (4) | −0.0252 (2) | 0.0559 (9) | |
H14A | 0.0488 | 0.3422 | −0.0430 | 0.084* | |
H14B | 0.1407 | 0.3343 | −0.0543 | 0.084* | |
H14C | 0.1014 | 0.4786 | −0.0439 | 0.084* | |
C12 | 0.2510 (2) | 0.4182 (3) | 0.1294 (2) | 0.0404 (7) | |
C13 | 0.1637 (2) | 0.3746 (3) | 0.0763 (2) | 0.0404 (7) | |
C15 | 0.19718 (19) | 0.3240 (3) | 0.2260 (2) | 0.0376 (7) | |
C16 | 0.1986 (2) | 0.2815 (3) | 0.3088 (2) | 0.0451 (7) | |
H16 | 0.1481 | 0.2360 | 0.3103 | 0.054* | |
C17 | 0.2775 (2) | 0.3094 (4) | 0.3884 (2) | 0.0537 (8) | |
H17 | 0.2801 | 0.2820 | 0.4444 | 0.064* | |
C18 | 0.3536 (2) | 0.3776 (4) | 0.3872 (2) | 0.0534 (8) | |
H18 | 0.4057 | 0.3961 | 0.4422 | 0.064* | |
C19 | 0.3518 (2) | 0.4174 (3) | 0.3050 (2) | 0.0507 (8) | |
H19 | 0.4027 | 0.4623 | 0.3042 | 0.061* | |
C20 | 0.27401 (19) | 0.3904 (3) | 0.2236 (2) | 0.0393 (7) | |
C21 | 0.0393 (2) | 0.2605 (3) | 0.1012 (2) | 0.0476 (8) | |
C22 | −0.0658 (2) | 0.1391 (4) | 0.1484 (2) | 0.0542 (9) | |
C23 | −0.0521 (3) | 0.0973 (5) | 0.2429 (3) | 0.0806 (13) | |
H23A | −0.0023 | 0.0314 | 0.2682 | 0.121* | |
H23B | −0.1082 | 0.0562 | 0.2389 | 0.121* | |
H23C | −0.0371 | 0.1777 | 0.2817 | 0.121* | |
C24 | −0.0771 (3) | 0.0154 (4) | 0.0874 (3) | 0.0829 (12) | |
H24A | −0.0255 | −0.0464 | 0.1173 | 0.124* | |
H24B | −0.0793 | 0.0459 | 0.0302 | 0.124* | |
H24C | −0.1338 | −0.0320 | 0.0759 | 0.124* | |
C25 | −0.1444 (2) | 0.2408 (5) | 0.1069 (3) | 0.0769 (12) | |
H25A | −0.1527 | 0.2662 | 0.0466 | 0.115* | |
H25B | −0.1304 | 0.3220 | 0.1449 | 0.115* | |
H25C | −0.2005 | 0.1991 | 0.1028 | 0.115* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.1213 (4) | 0.0499 (3) | 0.1235 (4) | 0.0187 (2) | 0.0738 (3) | −0.0069 (2) |
O1 | 0.0673 (15) | 0.0465 (15) | 0.0968 (19) | 0.0139 (12) | 0.0474 (14) | 0.0101 (13) |
O2 | 0.0687 (15) | 0.0561 (15) | 0.0683 (15) | −0.0004 (12) | 0.0448 (13) | 0.0146 (12) |
O3 | 0.0632 (16) | 0.114 (2) | 0.0528 (16) | −0.0311 (15) | 0.0189 (13) | 0.0067 (15) |
O4 | 0.0489 (12) | 0.0553 (14) | 0.0505 (12) | −0.0162 (11) | 0.0227 (10) | 0.0038 (10) |
N1 | 0.0567 (16) | 0.0364 (16) | 0.082 (2) | 0.0024 (13) | 0.0422 (15) | 0.0006 (14) |
N2 | 0.0426 (13) | 0.0335 (14) | 0.0452 (14) | −0.0037 (11) | 0.0237 (12) | 0.0003 (11) |
C1 | 0.062 (2) | 0.0330 (19) | 0.066 (2) | 0.0045 (16) | 0.0249 (18) | 0.0017 (16) |
C2 | 0.0547 (18) | 0.0345 (18) | 0.0562 (19) | −0.0033 (15) | 0.0268 (16) | 0.0012 (14) |
C3 | 0.0484 (17) | 0.0322 (17) | 0.0484 (18) | −0.0027 (14) | 0.0231 (15) | 0.0042 (13) |
C4 | 0.0460 (17) | 0.0392 (18) | 0.0475 (17) | −0.0070 (14) | 0.0244 (15) | −0.0019 (14) |
C5 | 0.0497 (18) | 0.0348 (17) | 0.0489 (18) | −0.0037 (14) | 0.0272 (15) | −0.0040 (14) |
C6 | 0.0510 (19) | 0.060 (2) | 0.071 (2) | 0.0018 (18) | 0.0331 (18) | 0.0040 (18) |
C7 | 0.0451 (17) | 0.050 (2) | 0.0492 (18) | −0.0044 (16) | 0.0255 (15) | 0.0002 (15) |
C8 | 0.052 (2) | 0.056 (2) | 0.083 (2) | −0.0058 (17) | 0.0392 (19) | 0.0059 (19) |
C9 | 0.0470 (17) | 0.0425 (19) | 0.0505 (18) | −0.0052 (15) | 0.0212 (15) | 0.0082 (15) |
C10 | 0.062 (2) | 0.043 (2) | 0.077 (2) | −0.0082 (18) | 0.0308 (19) | 0.0171 (18) |
C11 | 0.067 (2) | 0.0293 (19) | 0.084 (3) | −0.0055 (18) | 0.024 (2) | 0.0081 (17) |
C14 | 0.063 (2) | 0.059 (2) | 0.051 (2) | −0.0106 (18) | 0.0301 (17) | 0.0022 (17) |
C12 | 0.0488 (18) | 0.0288 (16) | 0.0482 (18) | 0.0001 (13) | 0.0257 (15) | 0.0000 (13) |
C13 | 0.0494 (17) | 0.0288 (16) | 0.0494 (18) | −0.0029 (14) | 0.0279 (15) | 0.0000 (13) |
C15 | 0.0414 (16) | 0.0247 (15) | 0.0534 (19) | 0.0016 (13) | 0.0271 (15) | 0.0002 (13) |
C16 | 0.0476 (18) | 0.0396 (18) | 0.0522 (19) | 0.0040 (14) | 0.0259 (16) | 0.0007 (15) |
C17 | 0.061 (2) | 0.053 (2) | 0.052 (2) | 0.0126 (18) | 0.0289 (18) | 0.0041 (16) |
C18 | 0.0466 (18) | 0.053 (2) | 0.0486 (19) | 0.0052 (16) | 0.0106 (15) | −0.0094 (16) |
C19 | 0.0513 (19) | 0.048 (2) | 0.052 (2) | 0.0023 (16) | 0.0223 (17) | −0.0009 (15) |
C20 | 0.0404 (16) | 0.0293 (15) | 0.0478 (18) | 0.0009 (13) | 0.0191 (14) | −0.0047 (13) |
C21 | 0.0484 (19) | 0.045 (2) | 0.049 (2) | −0.0041 (15) | 0.0211 (17) | −0.0001 (15) |
C22 | 0.0475 (19) | 0.054 (2) | 0.060 (2) | −0.0169 (17) | 0.0229 (16) | 0.0019 (17) |
C23 | 0.072 (2) | 0.095 (3) | 0.072 (2) | −0.031 (2) | 0.030 (2) | 0.018 (2) |
C24 | 0.090 (3) | 0.061 (3) | 0.105 (3) | −0.032 (2) | 0.050 (3) | −0.020 (2) |
C25 | 0.053 (2) | 0.090 (3) | 0.087 (3) | −0.004 (2) | 0.031 (2) | 0.005 (2) |
Br1—C1 | 1.887 (3) | C11—H11 | 0.93 |
O1—C6 | 1.342 (4) | C14—C13 | 1.487 (4) |
O1—N1 | 1.403 (3) | C14—H14A | 0.96 |
O2—C9 | 1.384 (4) | C14—H14B | 0.96 |
O2—C8 | 1.436 (4) | C14—H14C | 0.96 |
O3—C21 | 1.195 (4) | C12—C13 | 1.347 (4) |
O4—C21 | 1.321 (4) | C12—C20 | 1.429 (4) |
O4—C22 | 1.492 (3) | C15—C16 | 1.396 (4) |
N1—C5 | 1.300 (4) | C15—C20 | 1.405 (4) |
N2—C21 | 1.388 (4) | C16—C17 | 1.376 (4) |
N2—C15 | 1.403 (4) | C16—H16 | 0.93 |
N2—C13 | 1.425 (3) | C17—C18 | 1.396 (5) |
C1—C11 | 1.372 (5) | C17—H17 | 0.93 |
C1—C2 | 1.382 (4) | C18—C19 | 1.376 (4) |
C2—C3 | 1.386 (4) | C18—H18 | 0.93 |
C2—H2 | 0.93 | C19—C20 | 1.383 (4) |
C3—C9 | 1.392 (4) | C19—H19 | 0.93 |
C3—C4 | 1.525 (4) | C22—C25 | 1.502 (5) |
C4—C12 | 1.518 (4) | C22—C23 | 1.503 (5) |
C4—C5 | 1.520 (4) | C22—C24 | 1.509 (5) |
C4—H4 | 0.98 | C23—H23A | 0.96 |
C5—C7 | 1.417 (4) | C23—H23B | 0.96 |
C6—C7 | 1.325 (5) | C23—H23C | 0.96 |
C6—H6 | 0.93 | C24—H24A | 0.96 |
C7—C8 | 1.491 (4) | C24—H24B | 0.96 |
C8—H8A | 0.97 | C24—H24C | 0.96 |
C8—H8B | 0.97 | C25—H25A | 0.96 |
C9—C10 | 1.383 (5) | C25—H25B | 0.96 |
C10—C11 | 1.378 (5) | C25—H25C | 0.96 |
C10—H10 | 0.93 | ||
C6—O1—N1 | 107.3 (2) | C13—C12—C20 | 109.2 (2) |
C9—O2—C8 | 113.6 (2) | C13—C12—C4 | 125.7 (3) |
C21—O4—C22 | 120.0 (2) | C20—C12—C4 | 125.1 (3) |
C5—N1—O1 | 105.8 (2) | C12—C13—N2 | 108.0 (2) |
C21—N2—C15 | 129.1 (2) | C12—C13—C14 | 129.0 (3) |
C21—N2—C13 | 122.4 (2) | N2—C13—C14 | 123.0 (3) |
C15—N2—C13 | 108.5 (2) | C16—C15—N2 | 131.8 (3) |
C11—C1—C2 | 121.5 (3) | C16—C15—C20 | 121.4 (3) |
C11—C1—Br1 | 118.9 (3) | N2—C15—C20 | 106.9 (2) |
C2—C1—Br1 | 119.6 (3) | C17—C16—C15 | 117.4 (3) |
C1—C2—C3 | 121.0 (3) | C17—C16—H16 | 121.3 |
C1—C2—H2 | 119.5 | C15—C16—H16 | 121.3 |
C3—C2—H2 | 119.5 | C16—C17—C18 | 121.9 (3) |
C2—C3—C9 | 117.2 (3) | C16—C17—H17 | 119.1 |
C2—C3—C4 | 121.0 (3) | C18—C17—H17 | 119.1 |
C9—C3—C4 | 121.0 (3) | C19—C18—C17 | 120.1 (3) |
C12—C4—C5 | 110.4 (2) | C19—C18—H18 | 119.9 |
C12—C4—C3 | 113.6 (2) | C17—C18—H18 | 119.9 |
C5—C4—C3 | 115.6 (2) | C18—C19—C20 | 119.7 (3) |
C12—C4—H4 | 105.4 | C18—C19—H19 | 120.1 |
C5—C4—H4 | 105.4 | C20—C19—H19 | 120.1 |
C3—C4—H4 | 105.4 | C19—C20—C15 | 119.5 (3) |
N1—C5—C7 | 111.7 (3) | C19—C20—C12 | 133.0 (3) |
N1—C5—C4 | 119.2 (3) | C15—C20—C12 | 107.5 (2) |
C7—C5—C4 | 128.4 (3) | O3—C21—O4 | 125.7 (3) |
C7—C6—O1 | 111.7 (3) | O3—C21—N2 | 123.6 (3) |
C7—C6—H6 | 124.2 | O4—C21—N2 | 110.6 (3) |
O1—C6—H6 | 124.2 | O4—C22—C25 | 110.1 (3) |
C6—C7—C5 | 103.6 (3) | O4—C22—C23 | 101.8 (3) |
C6—C7—C8 | 130.1 (3) | C25—C22—C23 | 110.3 (3) |
C5—C7—C8 | 126.3 (3) | O4—C22—C24 | 109.1 (3) |
O2—C8—C7 | 110.2 (3) | C25—C22—C24 | 112.9 (3) |
O2—C8—H8A | 109.6 | C23—C22—C24 | 112.1 (3) |
C7—C8—H8A | 109.6 | C22—C23—H23A | 109.5 |
O2—C8—H8B | 109.6 | C22—C23—H23B | 109.5 |
C7—C8—H8B | 109.6 | H23A—C23—H23B | 109.5 |
H8A—C8—H8B | 108.1 | C22—C23—H23C | 109.5 |
C10—C9—O2 | 117.2 (3) | H23A—C23—H23C | 109.5 |
C10—C9—C3 | 121.2 (3) | H23B—C23—H23C | 109.5 |
O2—C9—C3 | 121.5 (3) | C22—C24—H24A | 109.5 |
C11—C10—C9 | 121.0 (3) | C22—C24—H24B | 109.5 |
C11—C10—H10 | 119.5 | H24A—C24—H24B | 109.5 |
C9—C10—H10 | 119.5 | C22—C24—H24C | 109.5 |
C1—C11—C10 | 118.1 (3) | H24A—C24—H24C | 109.5 |
C1—C11—H11 | 121.0 | H24B—C24—H24C | 109.5 |
C10—C11—H11 | 121.0 | C22—C25—H25A | 109.5 |
C13—C14—H14A | 109.5 | C22—C25—H25B | 109.5 |
C13—C14—H14B | 109.5 | H25A—C25—H25B | 109.5 |
H14A—C14—H14B | 109.5 | C22—C25—H25C | 109.5 |
C13—C14—H14C | 109.5 | H25A—C25—H25C | 109.5 |
H14A—C14—H14C | 109.5 | H25B—C25—H25C | 109.5 |
H14B—C14—H14C | 109.5 | ||
C6—O1—N1—C5 | −0.5 (3) | C5—C4—C12—C20 | 59.5 (4) |
C11—C1—C2—C3 | 0.4 (5) | C3—C4—C12—C20 | −72.3 (4) |
Br1—C1—C2—C3 | −179.1 (2) | C20—C12—C13—N2 | −0.9 (3) |
C1—C2—C3—C9 | 0.4 (5) | C4—C12—C13—N2 | 179.0 (3) |
C1—C2—C3—C4 | −169.9 (3) | C20—C12—C13—C14 | 178.9 (3) |
C2—C3—C4—C12 | −8.4 (4) | C4—C12—C13—C14 | −1.3 (5) |
C9—C3—C4—C12 | −178.3 (3) | C21—N2—C13—C12 | 179.9 (3) |
C2—C3—C4—C5 | −137.6 (3) | C15—N2—C13—C12 | 0.0 (3) |
C9—C3—C4—C5 | 52.5 (4) | C21—N2—C13—C14 | 0.1 (4) |
O1—N1—C5—C7 | 0.0 (3) | C15—N2—C13—C14 | −179.8 (3) |
O1—N1—C5—C4 | 171.0 (2) | C21—N2—C15—C16 | 0.4 (5) |
C12—C4—C5—N1 | 26.0 (4) | C13—N2—C15—C16 | −179.7 (3) |
C3—C4—C5—N1 | 156.7 (3) | C21—N2—C15—C20 | −179.0 (3) |
C12—C4—C5—C7 | −164.6 (3) | C13—N2—C15—C20 | 0.9 (3) |
C3—C4—C5—C7 | −33.9 (4) | N2—C15—C16—C17 | −178.1 (3) |
N1—O1—C6—C7 | 1.0 (4) | C20—C15—C16—C17 | 1.2 (4) |
O1—C6—C7—C5 | −0.9 (4) | C15—C16—C17—C18 | 0.0 (5) |
O1—C6—C7—C8 | 179.3 (3) | C16—C17—C18—C19 | −0.9 (5) |
N1—C5—C7—C6 | 0.6 (4) | C17—C18—C19—C20 | 0.4 (5) |
C4—C5—C7—C6 | −169.4 (3) | C18—C19—C20—C15 | 0.8 (4) |
N1—C5—C7—C8 | −179.7 (3) | C18—C19—C20—C12 | 179.8 (3) |
C4—C5—C7—C8 | 10.3 (5) | C16—C15—C20—C19 | −1.7 (4) |
C9—O2—C8—C7 | 84.3 (3) | N2—C15—C20—C19 | 177.8 (3) |
C6—C7—C8—O2 | 145.6 (3) | C16—C15—C20—C12 | 179.1 (3) |
C5—C7—C8—O2 | −34.0 (4) | N2—C15—C20—C12 | −1.4 (3) |
C8—O2—C9—C10 | 110.5 (3) | C13—C12—C20—C19 | −177.6 (3) |
C8—O2—C9—C3 | −73.3 (4) | C4—C12—C20—C19 | 2.6 (5) |
C2—C3—C9—C10 | −0.7 (5) | C13—C12—C20—C15 | 1.4 (3) |
C4—C3—C9—C10 | 169.6 (3) | C4—C12—C20—C15 | −178.4 (3) |
C2—C3—C9—O2 | −176.7 (3) | C22—O4—C21—O3 | 4.0 (5) |
C4—C3—C9—O2 | −6.3 (4) | C22—O4—C21—N2 | −177.5 (2) |
O2—C9—C10—C11 | 176.4 (3) | C15—N2—C21—O3 | 176.7 (3) |
C3—C9—C10—C11 | 0.2 (5) | C13—N2—C21—O3 | −3.2 (5) |
C2—C1—C11—C10 | −0.8 (5) | C15—N2—C21—O4 | −1.8 (4) |
Br1—C1—C11—C10 | 178.7 (3) | C13—N2—C21—O4 | 178.3 (2) |
C9—C10—C11—C1 | 0.5 (5) | C21—O4—C22—C25 | −63.4 (4) |
C5—C4—C12—C13 | −120.3 (3) | C21—O4—C22—C23 | 179.7 (3) |
C3—C4—C12—C13 | 107.9 (3) | C21—O4—C22—C24 | 61.1 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
C14—H14A···O3 | 0.96 | 1.93 | 2.694 (4) | 135 |
C24—H24B···O3 | 0.96 | 2.37 | 2.961 (5) | 120 |
C11—H11···N1i | 0.93 | 2.53 | 3.404 (4) | 156 |
Symmetry code: (i) x, y+1, z. |
Experimental details
Crystal data | |
Chemical formula | C25H23BrN2O4 |
Mr | 495.36 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 16.0494 (6), 9.6497 (4), 16.2202 (7) |
β (°) | 116.267 (2) |
V (Å3) | 2252.66 (16) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.86 |
Crystal size (mm) | 0.20 × 0.20 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART APEXII area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2008) |
Tmin, Tmax | 0.982, 0.982 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 20668, 5584, 2780 |
Rint | 0.049 |
(sin θ/λ)max (Å−1) | 0.668 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.046, 0.134, 1.00 |
No. of reflections | 5584 |
No. of parameters | 289 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.40, −0.48 |
Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
C14—H14A···O3 | 0.96 | 1.93 | 2.694 (4) | 135 |
C24—H24B···O3 | 0.96 | 2.37 | 2.961 (5) | 120 |
C11—H11···N1i | 0.93 | 2.53 | 3.404 (4) | 156 |
Symmetry code: (i) x, y+1, z. |
References
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Nitrogen and oxygen containing heterocycles are ubiquitous substructures in myriad of biologically active natural products and small-molecule pharmaceuticals (Furstner, 2003; Liddell, 2002). The nitrile oxide cycloaddition is a useful method to prepare heterocyclic compounds (Caramella & Grunanger, 1984). Isoxazole, the cycloadduct of nitrile oxide, is regarded as a versatile synthetic precursor for γ-amino alcohols and β-hydroxy ketones. Isoxazoles are found in some natural products, such as ibotenic acid. Ibotenic acid is naturally occurring in mushrooms Amanita muscaria and Amanita pantherina. Ibotenic acid is a powerful neurotoxin that is used as a brain-lesioning agent and has shown to be highly neurotoxic when injected directly into the brains of mice and rats. Isoxazoles also form the basis for a number of drugs, including the COX-2 inhibitor valdecoxib. Valdecoxib is a prescription drug used in the treatment of osteoarthritis, rheumatoid arthritis, painful menstruation and menstrual symptoms (Stormer et al., 2004; Erdelyi et al., 2008).
In the title (Fig. 1), the indole ring system is planar within ±0.021 (2) Å. The oxepane ring adopts a twisted boat conformation with puckering parameters (Cremer & Pople, 1975) and asymmetry parameters (Nardelli, 1983) of q2 = 0.654 (3) Å, φ2 = 179.9 (3)°, q3 = 0.380 (3) Å, φ3 = 222.4 (3)° and Δs(C7) = 34.3 (3)°. The position of atom O2 which lies between bromobenzene and isooxazone rings is defined by torsion angles O2—C8—C7—C5 of -34.0 (4)° and O2—C9—C10—C11 of 176.4 (3)°.
The ester group [-C(═O)-O-C-] is coplanar with the indole ring system [dihedral angle 3.0 (2)°]. The planarity is facilitated by intramolecular C14—H14A···O3 C24—H24B···O3 hydrogen bonds (Table 1). A free rotation about the O4—C22 single bond [1.492 (3) Å] is restricted by the C24—H24B···O3 hydrogen bond. The angles around atom C4 [C12—C4—C3 = 113.6 (2)° and C5—C4—C3 = 115.6 (2)°] deviates significantly from ideal tetrahedral values which may be as a result of steric interactions between isooxazole, bromophenol and indole groups.
Atom C11 in the molecule at (x,y,z) acts as donar to atom N1 at (x, 1+y, z), forming a chain running along the b axis (Fig. 2).