The solid state structure of moschamindole {systematic name: 10-[2-(4-hydroxy-3-methoxyphenyl)]-1,2,3,4,10,10a-hexahydro-6H-furo[2,3,4-jk]pyrrolo[4,3,2-ef]-3-benzazocin-1-one}, C20H18N2O4 is similar to its solution state structure, previously determined by NMR, and evidence of intermolecular hydrogen bonding is now presented.
Supporting information
CCDC reference: 155899
Key indicators
- Single-crystal X-ray study
- T = 150 K
- Mean (C-C) = 0.005 Å
- R factor = 0.046
- wR factor = 0.097
- Data-to-parameter ratio = 7.5
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Alert Level C:
ABSMU_01 Alert C The ratio of given/expected absorption coefficient lies
outside the range 0.99 <> 1.01
Calculated value of mu = 0.105
Value of mu given = 0.110
PLAT_352 Alert C Short N-H Bond (0.87A) N(2) - H(2) = 0.76 Ang.
General Notes
REFLT_03
From the CIF: _diffrn_reflns_theta_max 27.50
From the CIF: _reflns_number_total 1839
Count of symmetry unique reflns 1859
Completeness (_total/calc) 98.92%
TEST3: Check Friedels for noncentro structure
Estimate of Friedel pairs measured 0
Fraction of Friedel pairs measured 0.000
Are heavy atom types Z>Si present no
Please check that the estimate of the number of Friedel pairs is
correct. If it is not, please give the correct count in the
_publ_section_exptl_refinement section of the submitted CIF.
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
2 Alert Level C = Please check
Moschamindole was obtained from the methanol extract of the seeds of Centaurea
moschata. Crystals for X-ray work were obtained from a methanol solution.
Friedel pairs were merged in the data set, and the absolute configuration was
not determined. H atoms were initially placed in calculated positions and
thereafter allowed to ride on their attached atoms. In the final cycles of
least squares, the coordinates of the H atoms attached to N1, N2 and O4 were
freely refined. Each H atom was given an equivalent Uiso set at
1.2Ueq for its attached atom. Hydrogen-bonding geometries were
obtained with PLATON (Spek, 1998).
Data collection: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); cell refinement: DENZO and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
{2-(3-methoxy-4-hydroxyphenyl)}-dihydrofuro[kl]-1
H-
pyrrolo[fg]-2-oxo-1,2,3,4,5,6-hexahydro-3-benzazocine
top
Crystal data top
C20H18N2O4 | F(000) = 368 |
Mr = 350.36 | Dx = 1.493 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
a = 4.8724 (3) Å | Cell parameters from 3310 reflections |
b = 15.2803 (9) Å | θ = 2.9–27.5° |
c = 10.6940 (7) Å | µ = 0.11 mm−1 |
β = 101.840 (3)° | T = 150 K |
V = 779.25 (8) Å3 | Plate, yellow |
Z = 2 | 0.4 × 0.2 × 0.05 mm |
Data collection top
Enraf Nonius KappaCCD area-detector diffractometer | 1272 reflections with I > 2σ(I) |
Radiation source: Enraf Nonius FR591 rotating anode | Rint = 0.080 |
Graphite monochromator | θmax = 27.5°, θmin = 3.3° |
Detector resolution: 9.091 pixels mm-1 | h = −6→6 |
ϕ and ω scans to fill Ewald sphere | k = −19→18 |
5565 measured reflections | l = −12→13 |
1839 independent reflections | |
Refinement top
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) = 0.097 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.99 | w = 1/[σ2(Fo2) + (0.0348P)2] where P = (Fo2 + 2Fc2)/3 |
1839 reflections | (Δ/σ)max = 0.007 |
245 parameters | Δρmax = 0.22 e Å−3 |
1 restraint | Δρmin = −0.28 e Å−3 |
Crystal data top
C20H18N2O4 | V = 779.25 (8) Å3 |
Mr = 350.36 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 4.8724 (3) Å | µ = 0.11 mm−1 |
b = 15.2803 (9) Å | T = 150 K |
c = 10.6940 (7) Å | 0.4 × 0.2 × 0.05 mm |
β = 101.840 (3)° | |
Data collection top
Enraf Nonius KappaCCD area-detector diffractometer | 1272 reflections with I > 2σ(I) |
5565 measured reflections | Rint = 0.080 |
1839 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.046 | 1 restraint |
wR(F2) = 0.097 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.99 | Δρmax = 0.22 e Å−3 |
1839 reflections | Δρmin = −0.28 e Å−3 |
245 parameters | |
Special details top
Experimental. Please note cell_measurement_ fields are not relevant to area detector data, the
entire data set is used to refine the cell, which is indexed from all observed
reflections in a 10 degree phi range. |
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 | x | y | z | Uiso*/Ueq | |
O1 | 1.0233 (5) | 0.56379 (17) | 0.8951 (2) | 0.0272 (6) | |
O2 | 0.8375 (5) | 0.37968 (15) | 0.6439 (2) | 0.0277 (6) | |
O3 | 0.2063 (5) | 0.29402 (17) | 1.0335 (2) | 0.0302 (6) | |
O4 | 0.3312 (5) | 0.37320 (18) | 1.2564 (2) | 0.0287 (6) | |
H4 | 0.188 (8) | 0.326 (3) | 1.229 (3) | 0.034* | |
N1 | 0.4571 (6) | 0.4431 (2) | 0.5244 (3) | 0.0253 (7) | |
H1 | 0.452 (8) | 0.409 (3) | 0.469 (4) | 0.030* | |
N2 | 0.8203 (7) | 0.7503 (2) | 0.4526 (3) | 0.0301 (8) | |
H2 | 0.922 (8) | 0.784 (3) | 0.435 (3) | 0.036* | |
C1 | 0.8558 (7) | 0.4855 (2) | 0.8585 (3) | 0.0210 (8) | |
H1A | 0.9837 | 0.4376 | 0.8422 | 0.025* | |
C2 | 0.6525 (7) | 0.5072 (2) | 0.7311 (3) | 0.0202 (8) | |
H2A | 0.4580 | 0.5169 | 0.7451 | 0.024* | |
C3 | 0.6552 (7) | 0.4363 (2) | 0.6300 (3) | 0.0198 (7) | |
C4 | 0.2289 (7) | 0.5057 (3) | 0.4966 (3) | 0.0249 (8) | |
H4A | 0.2013 | 0.5319 | 0.5778 | 0.030* | |
H4B | 0.0544 | 0.4744 | 0.4578 | 0.030* | |
C5 | 0.2770 (7) | 0.5787 (2) | 0.4074 (3) | 0.0262 (9) | |
H5A | 0.3016 | 0.5521 | 0.3259 | 0.031* | |
H5B | 0.1063 | 0.6155 | 0.3883 | 0.031* | |
C6 | 0.5239 (7) | 0.6368 (2) | 0.4562 (3) | 0.0242 (8) | |
C7 | 0.7173 (7) | 0.6401 (2) | 0.5761 (3) | 0.0229 (8) | |
C8 | 0.7749 (7) | 0.5910 (2) | 0.6915 (3) | 0.0183 (7) | |
C9 | 0.9907 (7) | 0.6167 (2) | 0.7875 (3) | 0.0244 (8) | |
C10 | 1.1662 (7) | 0.6868 (3) | 0.7815 (3) | 0.0284 (9) | |
H10 | 1.3128 | 0.7014 | 0.8517 | 0.034* | |
C11 | 1.1207 (7) | 0.7352 (2) | 0.6697 (4) | 0.0288 (9) | |
H11 | 1.2379 | 0.7835 | 0.6605 | 0.035* | |
C12 | 0.9010 (7) | 0.7118 (2) | 0.5717 (3) | 0.0249 (8) | |
C13 | 0.5985 (8) | 0.7047 (3) | 0.3855 (3) | 0.0297 (9) | |
H13 | 0.5065 | 0.7181 | 0.3005 | 0.036* | |
C14 | 0.7172 (7) | 0.4572 (2) | 0.9658 (3) | 0.0211 (8) | |
C15 | 0.7808 (7) | 0.4961 (2) | 1.0836 (3) | 0.0254 (8) | |
H15 | 0.9135 | 0.5424 | 1.0987 | 0.031* | |
C16 | 0.6509 (7) | 0.4678 (3) | 1.1822 (3) | 0.0265 (8) | |
H16 | 0.6957 | 0.4948 | 1.2639 | 0.032* | |
C17 | 0.4596 (7) | 0.4013 (2) | 1.1600 (3) | 0.0235 (8) | |
C18 | 0.3967 (7) | 0.3605 (2) | 1.0414 (3) | 0.0224 (8) | |
C19 | 0.5267 (7) | 0.3883 (2) | 0.9439 (3) | 0.0243 (8) | |
H19 | 0.4855 | 0.3603 | 0.8628 | 0.029* | |
C20 | 0.1393 (9) | 0.2442 (3) | 0.9195 (3) | 0.0347 (9) | |
H20A | 0.0760 | 0.2834 | 0.8468 | 0.042* | |
H20B | −0.0104 | 0.2026 | 0.9258 | 0.042* | |
H20C | 0.3059 | 0.2121 | 0.9072 | 0.042* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0309 (14) | 0.0320 (15) | 0.0196 (13) | −0.0107 (12) | 0.0070 (11) | −0.0003 (12) |
O2 | 0.0350 (14) | 0.0220 (14) | 0.0271 (13) | 0.0068 (13) | 0.0092 (11) | −0.0017 (11) |
O3 | 0.0382 (15) | 0.0291 (14) | 0.0253 (13) | −0.0074 (13) | 0.0114 (12) | −0.0014 (12) |
O4 | 0.0320 (13) | 0.0376 (16) | 0.0189 (12) | −0.0027 (13) | 0.0110 (11) | 0.0005 (12) |
N1 | 0.0330 (17) | 0.0222 (17) | 0.0220 (18) | −0.0033 (15) | 0.0091 (15) | −0.0054 (14) |
N2 | 0.036 (2) | 0.0203 (17) | 0.0371 (19) | −0.0026 (16) | 0.0153 (16) | 0.0080 (15) |
C1 | 0.0222 (17) | 0.0227 (19) | 0.0179 (18) | −0.0015 (16) | 0.0035 (15) | −0.0005 (14) |
C2 | 0.0222 (17) | 0.0197 (18) | 0.0202 (18) | −0.0012 (16) | 0.0076 (15) | −0.0019 (15) |
C3 | 0.0221 (17) | 0.0181 (18) | 0.0209 (18) | −0.0039 (17) | 0.0084 (16) | 0.0005 (15) |
C4 | 0.0222 (18) | 0.030 (2) | 0.023 (2) | −0.0012 (17) | 0.0050 (15) | 0.0009 (16) |
C5 | 0.0280 (19) | 0.032 (2) | 0.0197 (18) | 0.0056 (18) | 0.0070 (16) | 0.0012 (16) |
C6 | 0.027 (2) | 0.023 (2) | 0.026 (2) | 0.0059 (17) | 0.0121 (16) | 0.0009 (16) |
C7 | 0.0262 (19) | 0.018 (2) | 0.028 (2) | 0.0027 (16) | 0.0127 (16) | −0.0028 (16) |
C8 | 0.0214 (16) | 0.0162 (17) | 0.0196 (17) | 0.0018 (15) | 0.0098 (15) | −0.0007 (14) |
C9 | 0.0263 (19) | 0.028 (2) | 0.0217 (18) | −0.0019 (17) | 0.0126 (16) | −0.0013 (16) |
C10 | 0.0293 (19) | 0.031 (2) | 0.027 (2) | −0.0085 (19) | 0.0107 (16) | −0.0137 (18) |
C11 | 0.031 (2) | 0.023 (2) | 0.039 (2) | −0.0093 (18) | 0.0210 (18) | −0.0054 (18) |
C12 | 0.031 (2) | 0.017 (2) | 0.029 (2) | 0.0013 (17) | 0.0124 (17) | 0.0009 (16) |
C13 | 0.036 (2) | 0.029 (2) | 0.0264 (19) | 0.0074 (19) | 0.0123 (17) | 0.0090 (18) |
C14 | 0.0222 (17) | 0.0252 (19) | 0.0161 (17) | 0.0035 (16) | 0.0048 (14) | 0.0002 (15) |
C15 | 0.0261 (19) | 0.025 (2) | 0.026 (2) | 0.0004 (17) | 0.0072 (16) | 0.0007 (16) |
C16 | 0.0280 (18) | 0.031 (2) | 0.0200 (18) | 0.0011 (17) | 0.0043 (15) | −0.0030 (16) |
C17 | 0.0254 (17) | 0.030 (2) | 0.0157 (18) | 0.0050 (18) | 0.0063 (15) | 0.0055 (16) |
C18 | 0.0227 (18) | 0.0218 (18) | 0.0227 (18) | 0.0018 (16) | 0.0051 (15) | 0.0028 (16) |
C19 | 0.0268 (18) | 0.029 (2) | 0.0177 (17) | 0.0018 (18) | 0.0066 (14) | −0.0003 (16) |
C20 | 0.050 (2) | 0.025 (2) | 0.029 (2) | −0.007 (2) | 0.0082 (19) | −0.0022 (18) |
Geometric parameters (Å, º) top
O1—C9 | 1.389 (4) | C5—C6 | 1.500 (5) |
O1—C1 | 1.456 (4) | C6—C13 | 1.376 (5) |
O2—C3 | 1.227 (4) | C6—C7 | 1.428 (5) |
O3—C18 | 1.366 (4) | C7—C12 | 1.422 (5) |
O3—C20 | 1.417 (4) | C7—C8 | 1.422 (5) |
O4—C17 | 1.380 (4) | C8—C9 | 1.367 (4) |
N1—C3 | 1.331 (4) | C9—C10 | 1.380 (5) |
N1—C4 | 1.451 (5) | C10—C11 | 1.384 (5) |
N2—C13 | 1.360 (5) | C11—C12 | 1.383 (5) |
N2—C12 | 1.384 (4) | C14—C15 | 1.370 (5) |
C1—C14 | 1.509 (5) | C14—C19 | 1.391 (5) |
C1—C2 | 1.546 (4) | C15—C16 | 1.404 (5) |
C2—C8 | 1.510 (5) | C16—C17 | 1.367 (5) |
C2—C3 | 1.532 (5) | C17—C18 | 1.389 (5) |
C4—C5 | 1.516 (5) | C18—C19 | 1.393 (4) |
| | | |
C9—O1—C1 | 107.0 (2) | C7—C8—C2 | 132.2 (3) |
C18—O3—C20 | 119.1 (3) | C8—C9—C10 | 125.2 (3) |
C3—N1—C4 | 128.1 (3) | C8—C9—O1 | 113.2 (3) |
C13—N2—C12 | 108.2 (3) | C10—C9—O1 | 121.6 (3) |
O1—C1—C14 | 110.2 (3) | C9—C10—C11 | 117.6 (3) |
O1—C1—C2 | 106.5 (3) | C12—C11—C10 | 118.6 (3) |
C14—C1—C2 | 115.2 (3) | C11—C12—N2 | 128.1 (3) |
C8—C2—C3 | 109.9 (2) | C11—C12—C7 | 124.6 (3) |
C8—C2—C1 | 102.1 (3) | N2—C12—C7 | 107.2 (3) |
C3—C2—C1 | 111.9 (3) | N2—C13—C6 | 111.5 (3) |
O2—C3—N1 | 122.6 (3) | C15—C14—C19 | 120.0 (3) |
O2—C3—C2 | 121.6 (3) | C15—C14—C1 | 121.5 (3) |
N1—C3—C2 | 115.8 (3) | C19—C14—C1 | 118.5 (3) |
N1—C4—C5 | 113.8 (3) | C14—C15—C16 | 120.4 (3) |
C6—C5—C4 | 115.6 (3) | C17—C16—C15 | 119.6 (3) |
C13—C6—C7 | 105.5 (3) | C16—C17—O4 | 119.9 (3) |
C13—C6—C5 | 122.6 (3) | C16—C17—C18 | 120.5 (3) |
C7—C6—C5 | 131.9 (3) | O4—C17—C18 | 119.6 (3) |
C12—C7—C8 | 114.9 (3) | O3—C18—C17 | 114.2 (3) |
C12—C7—C6 | 107.5 (3) | O3—C18—C19 | 125.9 (3) |
C8—C7—C6 | 137.5 (3) | C17—C18—C19 | 119.8 (3) |
C9—C8—C7 | 119.0 (3) | C14—C19—C18 | 119.7 (3) |
C9—C8—C2 | 108.7 (3) | | |
| | | |
C9—O1—C1—C14 | −141.6 (3) | C8—C9—C10—C11 | 0.0 (5) |
C9—O1—C1—C2 | −16.1 (3) | O1—C9—C10—C11 | 179.1 (3) |
O1—C1—C2—C8 | 13.1 (3) | C9—C10—C11—C12 | 1.1 (5) |
C14—C1—C2—C8 | 135.5 (3) | C10—C11—C12—N2 | −179.4 (3) |
O1—C1—C2—C3 | 130.6 (3) | C10—C11—C12—C7 | −0.9 (5) |
C14—C1—C2—C3 | −107.0 (3) | C13—N2—C12—C11 | 178.4 (3) |
C4—N1—C3—O2 | 179.1 (3) | C13—N2—C12—C7 | −0.3 (4) |
C4—N1—C3—C2 | −4.2 (4) | C8—C7—C12—C11 | −0.4 (5) |
C8—C2—C3—O2 | 99.8 (4) | C6—C7—C12—C11 | −178.8 (3) |
C1—C2—C3—O2 | −12.9 (4) | C8—C7—C12—N2 | 178.3 (3) |
C8—C2—C3—N1 | −76.9 (3) | C6—C7—C12—N2 | −0.1 (4) |
C1—C2—C3—N1 | 170.4 (3) | C12—N2—C13—C6 | 0.6 (4) |
C3—N1—C4—C5 | 103.1 (4) | C7—C6—C13—N2 | −0.7 (4) |
N1—C4—C5—C6 | −62.5 (4) | C5—C6—C13—N2 | 177.0 (3) |
C4—C5—C6—C13 | 178.7 (3) | O1—C1—C14—C15 | −7.8 (5) |
C4—C5—C6—C7 | −4.4 (5) | C2—C1—C14—C15 | −128.3 (4) |
C13—C6—C7—C12 | 0.4 (4) | O1—C1—C14—C19 | 173.9 (3) |
C5—C6—C7—C12 | −176.9 (3) | C2—C1—C14—C19 | 53.5 (4) |
C13—C6—C7—C8 | −177.4 (4) | C19—C14—C15—C16 | −1.1 (5) |
C5—C6—C7—C8 | 5.2 (7) | C1—C14—C15—C16 | −179.4 (3) |
C12—C7—C8—C9 | 1.5 (4) | C14—C15—C16—C17 | −0.1 (5) |
C6—C7—C8—C9 | 179.2 (4) | C15—C16—C17—O4 | 180.0 (3) |
C12—C7—C8—C2 | −173.6 (3) | C15—C16—C17—C18 | 1.1 (5) |
C6—C7—C8—C2 | 4.1 (6) | C20—O3—C18—C17 | −176.1 (3) |
C3—C2—C8—C9 | −124.7 (3) | C20—O3—C18—C19 | 3.4 (5) |
C1—C2—C8—C9 | −5.7 (3) | C16—C17—C18—O3 | 178.8 (3) |
C3—C2—C8—C7 | 50.8 (5) | O4—C17—C18—O3 | −0.1 (5) |
C1—C2—C8—C7 | 169.8 (3) | C16—C17—C18—C19 | −0.8 (5) |
C7—C8—C9—C10 | −1.4 (5) | O4—C17—C18—C19 | −179.7 (3) |
C2—C8—C9—C10 | 174.8 (3) | C15—C14—C19—C18 | 1.4 (5) |
C7—C8—C9—O1 | 179.5 (3) | C1—C14—C19—C18 | 179.7 (3) |
C2—C8—C9—O1 | −4.3 (4) | O3—C18—C19—C14 | 180.0 (3) |
C1—O1—C9—C8 | 13.1 (4) | C17—C18—C19—C14 | −0.5 (5) |
C1—O1—C9—C10 | −166.0 (3) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O4i | 0.79 (4) | 2.29 (4) | 3.002 (4) | 150 (4) |
N2—H2···O2ii | 0.76 (4) | 2.15 (4) | 2.909 (4) | 171 (3) |
O4—H4···O3 | 1.00 (4) | 2.17 (3) | 2.631 (5) | 106 (2) |
C1—H1A···O2 | 1.00 | 2.27 | 2.794 (4) | 111 |
C11—H11···O4iii | 0.95 | 2.51 | 3.367 (4) | 150 |
C15—H15···O1 | 0.94 | 2.37 | 2.740 (4) | 103 |
Symmetry codes: (i) x, y, z−1; (ii) −x+2, y+1/2, −z+1; (iii) −x+2, y+1/2, −z+2. |
Experimental details
Crystal data |
Chemical formula | C20H18N2O4 |
Mr | 350.36 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 150 |
a, b, c (Å) | 4.8724 (3), 15.2803 (9), 10.6940 (7) |
β (°) | 101.840 (3) |
V (Å3) | 779.25 (8) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.4 × 0.2 × 0.05 |
|
Data collection |
Diffractometer | Enraf Nonius KappaCCD area-detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5565, 1839, 1272 |
Rint | 0.080 |
(sin θ/λ)max (Å−1) | 0.650 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.046, 0.097, 0.99 |
No. of reflections | 1839 |
No. of parameters | 245 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.22, −0.28 |
Selected geometric parameters (Å, º) topO2—C3 | 1.227 (4) | C7—C12 | 1.422 (5) |
C1—C14 | 1.509 (5) | C8—C9 | 1.367 (4) |
C6—C13 | 1.376 (5) | | |
| | | |
C13—C6—C7 | 105.5 (3) | C8—C7—C6 | 137.5 (3) |
C13—C6—C5 | 122.6 (3) | C9—C8—C7 | 119.0 (3) |
C7—C6—C5 | 131.9 (3) | C9—C8—C2 | 108.7 (3) |
C12—C7—C8 | 114.9 (3) | C7—C8—C2 | 132.2 (3) |
C12—C7—C6 | 107.5 (3) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O4i | .79 (4) | 2.29 (4) | 3.002 (4) | 150 (4) |
N2—H2···O2ii | .76 (4) | 2.15 (4) | 2.909 (4) | 171 (3) |
O4—H4···O3 | 1.00 (4) | 2.17 (3) | 2.631 (5) | 106 (2) |
C1—H1A···O2 | 1.00 | 2.27 | 2.794 (4) | 111 |
C11—H11···O4iii | 0.95 | 2.51 | 3.367 (4) | 150 |
C15—H15···O1 | 0.94 | 2.37 | 2.740 (4) | 103 |
Symmetry codes: (i) x, y, z−1; (ii) −x+2, y+1/2, −z+1; (iii) −x+2, y+1/2, −z+2. |
Moschamindole, (I), was obtained as one of four indole alkaloids from Centaurea moschata and its molecular structure was determined by extensive one-dimensional and two-dimensional NMR spectroscopy (Sarker et al., 1997). We undertook an X-ray study to confirm the structure determined from NMR data and to establish the presence of hydrogen bonding.
Each H atom (H1 and H2) at the donor N-atom positions (N1 and N2) is involved in an intermolecular hydrogen bond (with O4 and O2, respectively). There is also a weak C11—H11···O4 intermolecular hydrogen bond. Three short intramolecular distances are present where the H···A distance `closes' a five-membered ring. Details of these geometries are shown in Table 2. The absolute stereochemistry of the molecule has not been determined but the two chiral centres, C1 and C2, have the same designation (shown as R in Fig. 1). Here, the torsion angle H1—C1—C2—H2 is -115 (1)°. The eight-membered ring has a conformation where atoms C2, C4, C5, C6, C7 and C8 lie within 0.05 Å of a mean plane, with atoms N1 and C3 displaced to the same side of this plane by 1.15 (4) and 1.28 (4) Å, respectively. The other four rings adopt planar conformations and the dihedral angle between the aryl ring and the dihydrofuran ring is 43.3 (1)°. As a result of ring fusion, valency angle distortions are present around C6, C7 and C8 (Table 1).