Download citation
Download citation
link to html
In the title compound, 2-bromo-5,5-di­methoxy­benzo­[a]­anthracene-6,7,12(5H)­trione, C20H13BrO5, the two aromatic rings are essentially planar and make a dihedral angle of 15.1 (2)° with one another, while the di­methoxy-substituted cyclo­hexane ring is non-planar, as expected. An intramolecular C—H...O interaction is present, with C...O = 2.814 (5) Å and C—H...O = 125°.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801012892/ci6048sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536801012892/ci6048Isup2.hkl
Contains datablock I

CCDC reference: 172201

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.006 Å
  • R factor = 0.066
  • wR factor = 0.165
  • Data-to-parameter ratio = 16.5

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry








Comment top

The analogues of angucyclines have been intensively investigated due to their biological properties (Krohn & Rohr, 1997). In order to generate a new analogue, we have prepared the title compound, (I). We have undertaken an X-ray structural determination of compound (I) to define the conformation of this system especially the conformation of the bromophenyl with respect to the substituted anthracene moiety.

In (I), the bond lengths and angles have normal values. In the aromatic rings A and D, the average C—C bond distances are 1.387 and 1.395 Å, respectively. In comparison, the C—C bond distances within the cyclohexanedione (ring B) and that of C6A—C12A are slightly shorter than in the related structure, benz[a]anthracene-7,12-dione, (II), previously studied (Kuroda et al., 1982), while the observed intramolecular interaction between C1A—H1A and O5 in (I) is a slightly longer than in (II) (2.058 Å).

The aromatic rings A and D are essentially planar, and atom Br1 deviates slightly (by 0.035 Å) from the least-square plane through ring D. The angle between these two aromatic rings is 15.1 (2)° and is much larger than in (II) benz[a]anthracene-7,12-dione (Kuroda et al., 1982), because in (I), ring C bridging between rings A and D is non-planar. The close interaction between O5 and H1A, and the non-bonded lone-pair–lone-pair repulsions of the O atoms [the non-bonded distance between O1 and O2 is 2.880 (5) Å] are two reasons for the distortions from planarity. Atom O1 lies on, while atom O5 deviates slightly by -0.121 (4) Å from the least-squares plane through ring B having a maximum deviation of 0.052 (4) Å (C12A). Atom O2 attached to ring C at C6 significantly deviates by -1.087 (4) Å, while atom C6 deviates by -0.317 (4) Å from the least-squares plane through ring C. The puckering parameters of ring C (Cremer & Pople, 1975), which adopt a half-chair conformation, are QT = 0.478 (5) Å, θ = 115.5 (6)° and ϕ2 = 275.5 (6)°.

Experimental top

To a solution of 2-bromo-6-hydroxy-5-methoxybenz[a]anthracene in methanol was added an equimolar amount of phenyliodonium acetate. The mixture was stirred for 3 h at room temperature. After stirring, the solvent was removed in vacuo, and the residue was isolated by column chromatography. The residue afforded a brown–red solid and was recrystallized from a mixture of ethyl acetate and petroleum ether (25/75).

Refinement top

After checking their presence in the difference map, all H atoms were geometrically fixed and allowed to ride on their attached atoms.

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL, PARST (Nardelli, 1995) and PLATON (Spek, 1990).

Figures top
[Figure 1] Fig. 1. The structure of title compound showing 50% probability displacement ellipsoids and the atom-numbering scheme.
#2-Bromo-benz[a]anthracene-5,6,7,12-tetraone-5-dimethyl ketal 2-Bromo-5,5-dimethoxybenzo[a]anthracene-6,7,12(5H)trione top
Crystal data top
C20H13BrO5F(000) = 416
Mr = 413.21Dx = 1.670 Mg m3
Triclinic, P1Melting point: 478 K
a = 7.7414 (1) ÅMo Kα radiation, λ = 0.71073 Å
b = 10.3084 (1) ÅCell parameters from 3602 reflections
c = 10.9583 (2) Åθ = 2.0–28.3°
α = 74.415 (1)°µ = 2.53 mm1
β = 78.835 (1)°T = 293 K
γ = 81.192 (1)°Slab, brown-red
V = 821.65 (2) Å30.36 × 0.26 × 0.10 mm
Z = 2
Data collection top
Siemens SMART CCD
diffractometer
3910 independent reflections
Radiation source: fine-focus sealed tube2584 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.055
Detector resolution: 8.33 pixels mm-1θmax = 28.3°, θmin = 2.0°
ω scansh = 1010
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
k = 1213
Tmin = 0.463, Tmax = 0.786l = 1410
5992 measured reflections
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)] = 0.066Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.165H-atom parameters constrained
S = 0.94 w = 1/[σ2(Fo2) + (0.0817P)2]
where P = (Fo2 + 2Fc2)/3
3910 reflections(Δ/σ)max < 0.001
237 parametersΔρmax = 0.97 e Å3
0 restraintsΔρmin = 1.79 e Å3
Crystal data top
C20H13BrO5γ = 81.192 (1)°
Mr = 413.21V = 821.65 (2) Å3
Triclinic, P1Z = 2
a = 7.7414 (1) ÅMo Kα radiation
b = 10.3084 (1) ŵ = 2.53 mm1
c = 10.9583 (2) ÅT = 293 K
α = 74.415 (1)°0.36 × 0.26 × 0.10 mm
β = 78.835 (1)°
Data collection top
Siemens SMART CCD
diffractometer
3910 independent reflections
Absorption correction: empirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
2584 reflections with I > 2σ(I)
Tmin = 0.463, Tmax = 0.786Rint = 0.055
5992 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0660 restraints
wR(F2) = 0.165H-atom parameters constrained
S = 0.94Δρmax = 0.97 e Å3
3910 reflectionsΔρmin = 1.79 e Å3
237 parameters
Special details top

Experimental. The data collection covered over a hemisphere of reciprocal space by a combination of three sets of exposures; each set had a different ϕ angle (0, 88 and 180°) for the crystal and each exposure of 10 s covered 0.3° in ω. The crystal-to-detector distance was 4 cm and the detector swing angle was -35°. Crystal decay was monitored by repeating fifty initial frames at the end of data collection and analysing the intensity of duplicate reflections, and was found to be negligible.

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
Br10.57346 (6)0.92224 (5)0.32252 (4)0.0438 (2)
O10.1343 (5)0.9058 (4)0.4296 (3)0.0588 (11)
O20.0609 (4)0.6827 (3)0.3091 (4)0.0496 (9)
O30.3380 (4)0.7206 (3)0.3304 (3)0.0339 (7)
O40.2715 (4)0.5406 (3)0.2601 (3)0.0414 (8)
O50.1826 (5)1.1749 (3)0.0261 (3)0.0566 (10)
C10.3510 (5)0.9315 (4)0.0835 (4)0.0307 (9)
H1A0.31961.02130.12400.037*
C20.4709 (6)0.8504 (4)0.1502 (4)0.0326 (9)
C30.5201 (6)0.7159 (5)0.0940 (5)0.0417 (11)
H3A0.59920.66230.14020.050*
C40.4490 (7)0.6634 (4)0.0322 (5)0.0417 (11)
H4A0.48190.57340.07110.050*
C4A0.3284 (6)0.7424 (4)0.1031 (4)0.0297 (9)
C50.2551 (6)0.6801 (4)0.2428 (4)0.0303 (9)
C60.0648 (5)0.7460 (4)0.2697 (4)0.0293 (9)
C6A0.0531 (5)0.8976 (4)0.2343 (4)0.0266 (8)
C70.0620 (6)0.9695 (4)0.3271 (4)0.0330 (10)
C7A0.0786 (5)1.1200 (4)0.2898 (4)0.0307 (9)
C80.1782 (7)1.1923 (5)0.3753 (5)0.0447 (12)
H8A0.23061.14700.45620.054*
C90.1978 (7)1.3321 (5)0.3380 (5)0.0516 (13)
H9A0.26521.38140.39360.062*
C100.1183 (7)1.3987 (5)0.2190 (5)0.0549 (14)
H10A0.13351.49280.19510.066*
C110.0158 (7)1.3286 (5)0.1338 (5)0.0451 (12)
H11A0.03871.37480.05400.054*
C11A0.0040 (6)1.1872 (4)0.1703 (4)0.0308 (9)
C120.1186 (6)1.1131 (4)0.0790 (4)0.0313 (9)
C12A0.1479 (5)0.9610 (4)0.1228 (4)0.0237 (8)
C12B0.2766 (5)0.8792 (4)0.0443 (4)0.0253 (8)
C130.5292 (6)0.6987 (5)0.3130 (5)0.0452 (12)
H13A0.57120.73430.37300.068*
H13B0.57680.74390.22710.068*
H13C0.56660.60340.32730.068*
C140.2312 (7)0.4594 (5)0.3894 (5)0.0490 (13)
H14A0.17260.38400.38900.073*
H14B0.15530.51350.44140.073*
H14C0.33900.42670.42400.073*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0543 (3)0.0447 (3)0.0270 (3)0.0122 (2)0.00523 (19)0.00406 (18)
O10.078 (3)0.040 (2)0.038 (2)0.0023 (19)0.0183 (18)0.0004 (15)
O20.0394 (19)0.0369 (19)0.065 (2)0.0104 (16)0.0005 (16)0.0015 (16)
O30.0350 (16)0.0343 (16)0.0302 (16)0.0025 (13)0.0087 (13)0.0055 (12)
O40.066 (2)0.0194 (15)0.0302 (17)0.0032 (14)0.0054 (15)0.0016 (11)
O50.084 (3)0.0258 (17)0.042 (2)0.0013 (17)0.0177 (18)0.0001 (14)
C10.037 (2)0.026 (2)0.027 (2)0.0027 (18)0.0069 (17)0.0024 (15)
C20.042 (2)0.032 (2)0.022 (2)0.0103 (19)0.0008 (17)0.0042 (16)
C30.047 (3)0.035 (3)0.038 (3)0.000 (2)0.005 (2)0.0111 (19)
C40.060 (3)0.020 (2)0.038 (3)0.002 (2)0.001 (2)0.0072 (17)
C4A0.037 (2)0.022 (2)0.029 (2)0.0037 (17)0.0034 (17)0.0045 (15)
C50.039 (2)0.0185 (19)0.030 (2)0.0013 (17)0.0037 (18)0.0032 (15)
C60.034 (2)0.025 (2)0.026 (2)0.0025 (18)0.0063 (17)0.0013 (15)
C6A0.027 (2)0.0213 (19)0.031 (2)0.0026 (16)0.0085 (16)0.0057 (15)
C70.034 (2)0.031 (2)0.029 (2)0.0045 (18)0.0025 (18)0.0042 (17)
C7A0.031 (2)0.029 (2)0.033 (2)0.0051 (17)0.0096 (18)0.0105 (16)
C80.048 (3)0.043 (3)0.039 (3)0.004 (2)0.001 (2)0.014 (2)
C90.066 (3)0.036 (3)0.054 (3)0.006 (3)0.003 (3)0.024 (2)
C100.073 (4)0.028 (3)0.061 (4)0.004 (2)0.002 (3)0.019 (2)
C110.061 (3)0.024 (2)0.046 (3)0.000 (2)0.001 (2)0.0092 (19)
C11A0.033 (2)0.026 (2)0.033 (2)0.0024 (17)0.0081 (17)0.0079 (16)
C120.033 (2)0.023 (2)0.034 (2)0.0016 (17)0.0074 (18)0.0018 (16)
C12A0.0253 (19)0.0203 (19)0.026 (2)0.0008 (15)0.0088 (15)0.0058 (14)
C12B0.028 (2)0.0212 (19)0.025 (2)0.0003 (16)0.0031 (16)0.0060 (14)
C130.040 (3)0.047 (3)0.043 (3)0.004 (2)0.012 (2)0.004 (2)
C140.071 (3)0.028 (2)0.035 (3)0.005 (2)0.001 (2)0.0083 (18)
Geometric parameters (Å, º) top
Br1—C21.896 (4)C7A—C11A1.388 (6)
O1—C71.216 (5)C8—C91.381 (7)
O2—C61.200 (5)C9—C101.374 (7)
O3—C51.430 (5)C10—C111.387 (7)
O4—C51.388 (5)C11—C11A1.396 (6)
O3—C131.446 (5)C11A—C121.494 (6)
O4—C141.441 (5)C12—C12A1.506 (5)
O5—C121.208 (5)C12A—C12B1.498 (5)
C1—C21.386 (6)C1—H1A0.9300
C2—C31.385 (6)C3—H3A0.9300
C3—C41.379 (6)C4—H4A0.9300
C4—C4A1.402 (6)C8—H8A0.9300
C1—C12B1.400 (6)C9—H9A0.9300
C4A—C12B1.416 (5)C10—H10A0.9300
C4A—C51.525 (5)C11—H11A0.9300
C5—C61.534 (6)C13—H13A0.9600
C6—C6A1.499 (5)C13—H13B0.9600
C6A—C12A1.353 (6)C13—H13C0.9600
C6A—C71.493 (6)C14—H14A0.9600
C7—C7A1.487 (6)C14—H14B0.9600
C7A—C81.395 (6)C14—H14C0.9600
C5—O3—C13116.3 (3)O5—C12—C11A120.1 (4)
C5—O4—C14117.3 (3)O5—C12—C12A122.3 (4)
C2—C1—C12B120.5 (4)C11A—C12—C12A117.6 (4)
C1—C2—C3121.7 (4)C6A—C12A—C12B119.7 (3)
C1—C2—Br1120.4 (3)C6A—C12A—C12118.8 (3)
C3—C2—Br1118.0 (3)C12B—C12A—C12121.4 (3)
C4—C3—C2118.4 (4)C1—C12B—C4A118.2 (4)
C3—C4—C4A121.6 (4)C1—C12B—C12A123.5 (4)
C4—C4A—C12B119.6 (4)C4A—C12B—C12A118.3 (3)
C4—C4A—C5119.6 (4)C2—C1—H1A119.7
C12B—C4A—C5120.8 (3)C12B—C1—H1A119.7
O3—C5—O4112.9 (3)C4—C3—H3A120.8
O4—C5—C4A107.8 (3)C2—C3—H3A120.8
O3—C5—C4A112.4 (3)C3—C4—H4A119.2
O4—C5—C6114.9 (3)C4A—C4—H4A119.2
O3—C5—C6101.4 (3)C9—C8—H8A120.5
C4A—C5—C6107.3 (3)C7A—C8—H8A120.5
O2—C6—C5123.4 (4)C10—C9—H9A119.8
O2—C6—C6A124.1 (4)C8—C9—H9A119.8
C5—C6—C6A112.5 (3)C9—C10—H10A119.3
C12A—C6A—C7124.0 (4)C11—C10—H10A119.3
C12A—C6A—C6118.9 (4)C10—C11—H11A120.7
C7—C6A—C6117.1 (4)C11A—C11—H11A120.7
O1—C7—C7A122.5 (4)H13A—C13—H13B109.5
O1—C7—C6A120.5 (4)O3—C13—H13A109.5
C7A—C7—C6A117.1 (4)O3—C13—H13B109.5
C11A—C7A—C8120.7 (4)O3—C13—H13C109.5
C11A—C7A—C7119.8 (4)H13A—C13—H13C109.5
C8—C7A—C7119.5 (4)H13B—C13—H13C109.5
C9—C8—C7A119.0 (5)O4—C14—H14A109.5
C10—C9—C8120.3 (4)O4—C14—H14B109.5
C9—C10—C11121.5 (5)H14A—C14—H14B109.5
C10—C11—C11A118.6 (5)O4—C14—H14C109.5
C7A—C11A—C11119.8 (4)H14A—C14—H14C109.5
C7A—C11A—C12122.1 (4)H14B—C14—H14C109.5
C11—C11A—C12118.1 (4)
C12B—C1—C2—C30.6 (7)O1—C7—C7A—C81.0 (7)
C12B—C1—C2—Br1179.2 (3)C6A—C7—C7A—C8177.2 (4)
C1—C2—C3—C41.1 (7)C11A—C7A—C8—C91.8 (7)
Br1—C2—C3—C4178.7 (4)C7—C7A—C8—C9177.8 (5)
C2—C3—C4—C4A0.6 (8)C7A—C8—C9—C100.9 (8)
C3—C4—C4A—C12B0.5 (7)C8—C9—C10—C110.5 (9)
C3—C4—C4A—C5179.3 (4)C9—C10—C11—C11A0.9 (9)
C14—O4—C5—O347.5 (5)C8—C7A—C11A—C111.4 (7)
C14—O4—C5—C4A172.2 (4)C7—C7A—C11A—C11178.2 (4)
C14—O4—C5—C668.2 (5)C8—C7A—C11A—C12177.0 (4)
C13—O3—C5—O468.6 (5)C7—C7A—C11A—C123.3 (6)
C13—O3—C5—C4A53.6 (5)C10—C11—C11A—C7A0.1 (7)
C13—O3—C5—C6167.9 (3)C10—C11—C11A—C12178.4 (5)
C4—C4A—C5—O422.5 (5)C7A—C11A—C12—O5177.1 (5)
C12B—C4A—C5—O4157.8 (4)C11—C11A—C12—O54.4 (7)
C4—C4A—C5—O3102.6 (5)C7A—C11A—C12—C12A2.2 (6)
C12B—C4A—C5—O377.2 (5)C11—C11A—C12—C12A176.3 (4)
C4—C4A—C5—C6146.8 (4)C7—C6A—C12A—C12B172.4 (4)
C12B—C4A—C5—C633.5 (5)C6—C6A—C12A—C12B6.5 (6)
O3—C5—C6—O2118.4 (4)C7—C6A—C12A—C128.8 (6)
O4—C5—C6—O23.7 (6)C6—C6A—C12A—C12172.3 (3)
C4A—C5—C6—O2123.5 (4)O5—C12—C12A—C6A171.1 (5)
O4—C5—C6—C6A173.1 (3)C11A—C12—C12A—C6A8.2 (6)
O3—C5—C6—C6A64.8 (4)O5—C12—C12A—C12B7.7 (7)
C4A—C5—C6—C6A53.2 (4)C11A—C12—C12A—C12B173.0 (4)
O2—C6—C6A—C12A134.0 (5)C2—C1—C12B—C4A0.5 (6)
C5—C6—C6A—C12A42.7 (5)C2—C1—C12B—C12A179.3 (4)
O2—C6—C6A—C747.0 (6)C4—C4A—C12B—C11.0 (6)
C5—C6—C6A—C7136.3 (4)C5—C4A—C12B—C1178.8 (4)
C12A—C6A—C7—O1175.0 (5)C4—C4A—C12B—C12A179.8 (4)
C6—C6A—C7—O13.9 (6)C5—C4A—C12B—C12A0.1 (6)
C12A—C6A—C7—C7A3.2 (6)C6A—C12A—C12B—C1165.6 (4)
C6—C6A—C7—C7A177.9 (4)C12—C12A—C12B—C113.3 (6)
O1—C7—C7A—C11A178.7 (5)C6A—C12A—C12B—C4A15.6 (6)
C6A—C7—C7A—C11A3.1 (6)C12—C12A—C12B—C4A165.5 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1A···O50.932.182.814 (5)125

Experimental details

Crystal data
Chemical formulaC20H13BrO5
Mr413.21
Crystal system, space groupTriclinic, P1
Temperature (K)293
a, b, c (Å)7.7414 (1), 10.3084 (1), 10.9583 (2)
α, β, γ (°)74.415 (1), 78.835 (1), 81.192 (1)
V3)821.65 (2)
Z2
Radiation typeMo Kα
µ (mm1)2.53
Crystal size (mm)0.36 × 0.26 × 0.10
Data collection
DiffractometerSiemens SMART CCD
diffractometer
Absorption correctionEmpirical (using intensity measurements)
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.463, 0.786
No. of measured, independent and
observed [I > 2σ(I)] reflections
5992, 3910, 2584
Rint0.055
(sin θ/λ)max1)0.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.066, 0.165, 0.94
No. of reflections3910
No. of parameters237
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.97, 1.79

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SAINT, SHELXTL (Sheldrick, 1997), SHELXTL, PARST (Nardelli, 1995) and PLATON (Spek, 1990).

Selected geometric parameters (Å, º) top
Br1—C21.896 (4)C4—C4A1.402 (6)
O1—C71.216 (5)C1—C12B1.400 (6)
O2—C61.200 (5)C4A—C12B1.416 (5)
O3—C51.430 (5)C4A—C51.525 (5)
O4—C51.388 (5)C5—C61.534 (6)
O5—C121.208 (5)C6—C6A1.499 (5)
C1—C21.386 (6)C6A—C12A1.353 (6)
C2—C31.385 (6)C7A—C11A1.388 (6)
C3—C41.379 (6)C12A—C12B1.498 (5)
C5—O3—C13116.3 (3)O3—C5—O4112.9 (3)
C5—O4—C14117.3 (3)O2—C6—C5123.4 (4)
C1—C2—C3121.7 (4)O2—C6—C6A124.1 (4)
C1—C2—Br1120.4 (3)C5—C6—C6A112.5 (3)
C3—C2—Br1118.0 (3)
C12B—C4A—C5—C633.5 (5)C11—C11A—C12—O54.4 (7)
O4—C5—C6—O23.7 (6)C11A—C12—C12A—C12B173.0 (4)
O2—C6—C6A—C747.0 (6)C12—C12A—C12B—C113.3 (6)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C1—H1A···O50.932.182.814 (5)125
 

Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds