Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103026076/fr1450sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103026076/fr1450Isup2.hkl |
CCDC reference: 231048
To a stirred solution of diisopropylamine (1.923 g, 19 mmol) in tetrahyrofuran (THF, 20 ml) at 273 K under nitrogen was added a solution of 2.0 M n-butyllithium (9 ml, 18.8 mmol) and the mixture stirred at 273 K for 30 min. To this solution at 273 K was added 1-aza-bicyclo[2.2.2]octan-3-one hydrochloride (1.5 g, 9.28 mmol) in one portion, and stirring continued until the mixture dissolved completely (20 min). The temperature was lowered to 195 K and a solution of 1-acetyl-1H-indole-3-carboxaldehyde (1.722 g, 9.2 mmol) in THF (25 ml) was added dropwise. Stirring was continued for 30 min at this temperature, and then at 273 K for 90 min. The reaction mixture was poured into saturated NaHCO3 at 273 K and the resulting solution was extracted with CHCl3 (3x15 ml). The combined organic extracts were dried over anhydrous Na2SO4 and evaporated to afford (Z)-2-(1-acetyl-1H-indol-3-ylmethylene) −1-aza-bicyclo[2.2.2]octan-3-one, which was subsequently refluxed with 25 ml 1 N sodium hydroxide solution for 30 min. The reaction mixture was cooled to room temperature, and the yellow solid that separated was collected by filtration, washed with cold water and dried. Crystallization from methanol gave a yellow crystalline product suitable for X-ray analysis. 1H NMR (DMSO-d6, p.p.m): δ 1.76–2.04 (m, 4H), 2.46 (p, 1H), 2.82–2.91 (m, 2H), 3.11–3.20 (m, 2H), 7.10–7.20 (m, 2H), 7.25 (s, 1H), 7.46 (d, J=7.2 Hz, 1H), 7.89 (d, J=7.5 Hz, 1H), 8.31 (s, 1H), 11.78 (s, 1H); 13C NMR (DMSO-d6, p.p.m): δ 25.7, 39.9, 47.2, 109.4, 111.8, 117.3, 118.5, 120.2, 121.9, 127.1, 131.4, 135.7, 139.9, 203.3.
H atoms were placed at calculated positions and treated using a riding model (aromatic C—H = 0.95 Å, methylene C—H = 0.99 Å and N—H = 0.88 Å). Uiso(H) values were set to 1.2Ueq of the attached C or N atom. The absolute structure was not determined, and Friedel pairs were averaged.
Data collection: COLLECT (Nonius, 1999); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO–SMN (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL/PC (Sheldrick, 1995); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997) and local procedures.
C16H16N2O | F(000) = 1072 |
Mr = 252.31 | Dx = 1.323 Mg m−3 |
Monoclinic, Cc | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: C -2yc | Cell parameters from 22075 reflections |
a = 6.1800 (12) Å | θ = 1.0–27.5° |
b = 44.160 (9) Å | µ = 0.08 mm−1 |
c = 9.774 (2) Å | T = 173 K |
β = 108.26 (3)° | Broken lath, yellow |
V = 2533.1 (10) Å3 | 0.25 × 0.14 × 0.05 mm |
Z = 8 |
Nonius KappaCCD diffractometer | 2906 independent reflections |
Radiation source: fine-focus sealed tube | 2589 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.038 |
Detector resolution: 18 pixels mm-1 | θmax = 27.5°, θmin = 1.8° |
ω scans at fixed χ = 55° | h = −8→8 |
Absorption correction: multi-scan SCALEPACK (Otwinowski & Minor, 1997) | k = −56→56 |
Tmin = 0.979, Tmax = 0.996 | l = −12→12 |
28160 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.048 | H-atom parameters constrained |
wR(F2) = 0.080 | w = 1/[σ2(Fo2) + (0.0249P)2 + 0.9406P] where P = (Fo2 + 2Fc2)/3 |
S = 1.12 | (Δ/σ)max < 0.001 |
2906 reflections | Δρmax = 0.21 e Å−3 |
344 parameters | Δρmin = −0.17 e Å−3 |
2 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0035 (4) |
C16H16N2O | V = 2533.1 (10) Å3 |
Mr = 252.31 | Z = 8 |
Monoclinic, Cc | Mo Kα radiation |
a = 6.1800 (12) Å | µ = 0.08 mm−1 |
b = 44.160 (9) Å | T = 173 K |
c = 9.774 (2) Å | 0.25 × 0.14 × 0.05 mm |
β = 108.26 (3)° |
Nonius KappaCCD diffractometer | 2906 independent reflections |
Absorption correction: multi-scan SCALEPACK (Otwinowski & Minor, 1997) | 2589 reflections with I > 2σ(I) |
Tmin = 0.979, Tmax = 0.996 | Rint = 0.038 |
28160 measured reflections |
R[F2 > 2σ(F2)] = 0.048 | 2 restraints |
wR(F2) = 0.080 | H-atom parameters constrained |
S = 1.12 | Δρmax = 0.21 e Å−3 |
2906 reflections | Δρmin = −0.17 e Å−3 |
344 parameters |
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. Two molecules of the same species in the asymmetric unit of space group Cc is often (usually ?) a symptom of incorrect space group assignment. With this in mind, space group C2/c was tried in several different ways, but no satisfactory centrosymmetric structure could be found. Evidence in favour of Cc versus C2/c (in no particular order). 1) Solution easy in Cc, unobtainable in C2/c 2) Refinement straightforward in Cc, largest correlation coefficient was between scale factor and extinction parameter (0.525), all others were less than 0.5. 3) Inspection of two molecules - they are not exactly related. 4) ADDSYM in PLATON (as implemented by the IUCr checks for Acta Cryst) gives report "no additional symmetry detected". 5) E statistics point toward non-centrosymmetry. 6) Superposition of A onto B gives r.m.s. deviation of 1.124 A Superposition of A onto inverted B gives r.m.s dev. 0.220 A The second suggests that the two are almost inversion related but not quite. 7) A ttempts to make C2/c by moving to any of the alternative inversion centres in C2/c and then refining on one of the pair was unsuccesful. |
x | y | z | Uiso*/Ueq | ||
N1A | 1.0088 (3) | 0.47368 (5) | 0.2176 (2) | 0.0238 (5) | |
H1A | 1.0967 | 0.4780 | 0.1647 | 0.029* | |
C2A | 0.8549 (4) | 0.49267 (6) | 0.2437 (3) | 0.0227 (6) | |
H2A | 0.8256 | 0.5127 | 0.2073 | 0.027* | |
C3A | 0.7455 (4) | 0.47877 (6) | 0.3312 (3) | 0.0213 (5) | |
C4A | 0.8415 (4) | 0.44854 (6) | 0.3583 (3) | 0.0213 (6) | |
C5A | 0.8048 (5) | 0.42331 (6) | 0.4333 (3) | 0.0263 (6) | |
H5A | 0.6937 | 0.4240 | 0.4819 | 0.032* | |
C6A | 0.9304 (5) | 0.39732 (6) | 0.4369 (3) | 0.0295 (6) | |
H6A | 0.9050 | 0.3801 | 0.4881 | 0.035* | |
C7A | 1.0951 (5) | 0.39605 (6) | 0.3657 (3) | 0.0299 (7) | |
H7A | 1.1795 | 0.3779 | 0.3694 | 0.036* | |
C8A | 1.1368 (5) | 0.42052 (6) | 0.2908 (3) | 0.0287 (7) | |
H8A | 1.2500 | 0.4197 | 0.2439 | 0.034* | |
C9A | 1.0072 (4) | 0.44645 (6) | 0.2863 (3) | 0.0212 (6) | |
C10A | 0.5802 (4) | 0.49145 (6) | 0.3896 (3) | 0.0213 (6) | |
H10A | 0.5215 | 0.4780 | 0.4452 | 0.026* | |
C11A | 0.4963 (4) | 0.51992 (6) | 0.3765 (3) | 0.0229 (6) | |
N12A | 0.5588 (4) | 0.54340 (5) | 0.2928 (2) | 0.0266 (5) | |
C13A | 0.3466 (5) | 0.55629 (6) | 0.1910 (3) | 0.0283 (6) | |
H13A | 0.2646 | 0.5403 | 0.1237 | 0.034* | |
H13B | 0.3867 | 0.5726 | 0.1337 | 0.034* | |
C14A | 0.1880 (4) | 0.56931 (6) | 0.2725 (3) | 0.0262 (6) | |
H14A | 0.1640 | 0.5912 | 0.2527 | 0.031* | |
H14B | 0.0380 | 0.5591 | 0.2397 | 0.031* | |
C15A | 0.3004 (4) | 0.56405 (6) | 0.4339 (3) | 0.0239 (6) | |
H15A | 0.2004 | 0.5714 | 0.4900 | 0.029* | |
C16A | 0.5310 (5) | 0.58051 (6) | 0.4811 (3) | 0.0305 (7) | |
H16A | 0.6082 | 0.5773 | 0.5853 | 0.037* | |
H16B | 0.5082 | 0.6025 | 0.4633 | 0.037* | |
C17A | 0.6773 (4) | 0.56743 (6) | 0.3927 (3) | 0.0310 (7) | |
H17A | 0.7183 | 0.5840 | 0.3370 | 0.037* | |
H17B | 0.8203 | 0.5591 | 0.4596 | 0.037* | |
C18A | 0.3453 (4) | 0.53046 (6) | 0.4561 (3) | 0.0230 (6) | |
O18A | 0.2657 (3) | 0.51427 (4) | 0.5318 (2) | 0.0294 (5) | |
N1B | −0.1388 (4) | 0.77477 (5) | 0.5250 (2) | 0.0298 (5) | |
H1B | −0.2827 | 0.7717 | 0.4755 | 0.036* | |
C2B | 0.0299 (5) | 0.75371 (6) | 0.5504 (3) | 0.0272 (6) | |
H2B | 0.0097 | 0.7334 | 0.5163 | 0.033* | |
C3B | 0.2351 (4) | 0.76607 (6) | 0.6330 (3) | 0.0258 (6) | |
C4B | 0.1858 (4) | 0.79724 (6) | 0.6570 (3) | 0.0256 (6) | |
C5B | 0.3192 (5) | 0.82162 (6) | 0.7272 (3) | 0.0337 (7) | |
H5B | 0.4781 | 0.8192 | 0.7737 | 0.040* | |
C6B | 0.2161 (6) | 0.84929 (7) | 0.7280 (3) | 0.0388 (8) | |
H6B | 0.3061 | 0.8661 | 0.7738 | 0.047* | |
C7B | −0.0180 (5) | 0.85313 (7) | 0.6627 (3) | 0.0397 (8) | |
H7B | −0.0848 | 0.8723 | 0.6667 | 0.048* | |
C8B | −0.1541 (5) | 0.82947 (6) | 0.5924 (3) | 0.0335 (7) | |
H8B | −0.3134 | 0.8320 | 0.5481 | 0.040* | |
C9B | −0.0489 (5) | 0.80175 (6) | 0.5890 (3) | 0.0282 (6) | |
C10B | 0.4539 (4) | 0.75192 (6) | 0.6913 (3) | 0.0266 (6) | |
H10B | 0.5715 | 0.7646 | 0.7487 | 0.032* | |
C11B | 0.5161 (5) | 0.72328 (6) | 0.6764 (3) | 0.0269 (6) | |
N12B | 0.3649 (4) | 0.70066 (5) | 0.5899 (3) | 0.0313 (6) | |
C13B | 0.3347 (5) | 0.67665 (7) | 0.6879 (3) | 0.0370 (8) | |
H13C | 0.2332 | 0.6607 | 0.6307 | 0.044* | |
H13D | 0.2603 | 0.6854 | 0.7551 | 0.044* | |
C14B | 0.5646 (5) | 0.66224 (7) | 0.7755 (3) | 0.0364 (7) | |
H14C | 0.5893 | 0.6648 | 0.8799 | 0.044* | |
H14D | 0.5634 | 0.6403 | 0.7544 | 0.044* | |
C15B | 0.7570 (5) | 0.67793 (6) | 0.7334 (3) | 0.0307 (7) | |
H15B | 0.9093 | 0.6696 | 0.7900 | 0.037* | |
C16B | 0.7123 (5) | 0.67355 (7) | 0.5715 (3) | 0.0346 (7) | |
H16C | 0.7144 | 0.6517 | 0.5490 | 0.042* | |
H16D | 0.8323 | 0.6838 | 0.5412 | 0.042* | |
C17B | 0.4751 (5) | 0.68730 (7) | 0.4899 (3) | 0.0384 (8) | |
H17C | 0.4936 | 0.7031 | 0.4227 | 0.046* | |
H17D | 0.3757 | 0.6713 | 0.4322 | 0.046* | |
C18B | 0.7440 (5) | 0.71166 (6) | 0.7582 (3) | 0.0282 (6) | |
O18B | 0.9001 (3) | 0.72689 (5) | 0.8357 (2) | 0.0362 (5) |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1A | 0.0216 (11) | 0.0285 (12) | 0.0246 (12) | −0.0013 (10) | 0.0120 (10) | 0.0009 (10) |
C2A | 0.0223 (14) | 0.0235 (13) | 0.0231 (15) | 0.0000 (12) | 0.0080 (12) | 0.0003 (12) |
C3A | 0.0168 (12) | 0.0236 (13) | 0.0221 (14) | −0.0003 (11) | 0.0042 (10) | 0.0002 (12) |
C4A | 0.0173 (13) | 0.0262 (14) | 0.0178 (14) | −0.0022 (11) | 0.0020 (11) | −0.0023 (11) |
C5A | 0.0237 (14) | 0.0302 (15) | 0.0234 (15) | −0.0036 (12) | 0.0051 (12) | −0.0013 (12) |
C6A | 0.0352 (16) | 0.0230 (14) | 0.0271 (16) | −0.0019 (12) | 0.0050 (13) | 0.0030 (12) |
C7A | 0.0334 (16) | 0.0234 (14) | 0.0300 (16) | 0.0083 (12) | 0.0057 (13) | −0.0012 (12) |
C8A | 0.0249 (15) | 0.0332 (16) | 0.0277 (16) | 0.0034 (12) | 0.0076 (12) | −0.0039 (13) |
C9A | 0.0167 (13) | 0.0249 (14) | 0.0203 (14) | −0.0033 (11) | 0.0032 (11) | −0.0037 (12) |
C10A | 0.0183 (13) | 0.0275 (14) | 0.0180 (14) | −0.0029 (11) | 0.0055 (11) | 0.0039 (11) |
C11A | 0.0185 (13) | 0.0272 (14) | 0.0247 (14) | −0.0003 (11) | 0.0093 (11) | 0.0026 (12) |
N12A | 0.0270 (12) | 0.0263 (12) | 0.0303 (13) | 0.0055 (10) | 0.0144 (10) | 0.0077 (11) |
C13A | 0.0339 (16) | 0.0277 (14) | 0.0257 (16) | 0.0061 (12) | 0.0129 (13) | 0.0053 (12) |
C14A | 0.0240 (14) | 0.0252 (14) | 0.0292 (15) | 0.0029 (11) | 0.0081 (12) | 0.0047 (12) |
C15A | 0.0190 (13) | 0.0312 (14) | 0.0234 (15) | 0.0022 (11) | 0.0093 (11) | −0.0002 (12) |
C16A | 0.0256 (14) | 0.0305 (15) | 0.0332 (17) | −0.0012 (12) | 0.0062 (13) | −0.0020 (13) |
C17A | 0.0215 (14) | 0.0296 (15) | 0.0433 (18) | 0.0002 (12) | 0.0123 (13) | 0.0082 (14) |
C18A | 0.0169 (14) | 0.0298 (15) | 0.0208 (14) | −0.0003 (11) | 0.0037 (11) | 0.0013 (12) |
O18A | 0.0273 (11) | 0.0350 (11) | 0.0315 (12) | 0.0022 (8) | 0.0174 (9) | 0.0044 (9) |
N1B | 0.0188 (12) | 0.0366 (13) | 0.0321 (14) | 0.0001 (10) | 0.0051 (10) | 0.0034 (11) |
C2B | 0.0238 (14) | 0.0280 (15) | 0.0273 (16) | 0.0035 (12) | 0.0046 (12) | 0.0051 (12) |
C3B | 0.0231 (14) | 0.0307 (15) | 0.0242 (15) | 0.0024 (12) | 0.0084 (12) | 0.0046 (12) |
C4B | 0.0218 (14) | 0.0336 (16) | 0.0225 (14) | 0.0007 (11) | 0.0085 (11) | 0.0027 (12) |
C5B | 0.0293 (16) | 0.0405 (17) | 0.0294 (16) | 0.0020 (14) | 0.0065 (13) | 0.0008 (14) |
C6B | 0.048 (2) | 0.0311 (16) | 0.0385 (19) | −0.0018 (15) | 0.0148 (16) | −0.0031 (14) |
C7B | 0.050 (2) | 0.0367 (17) | 0.0343 (18) | 0.0146 (15) | 0.0168 (16) | 0.0059 (15) |
C8B | 0.0318 (16) | 0.0392 (17) | 0.0311 (17) | 0.0118 (14) | 0.0121 (14) | 0.0081 (14) |
C9B | 0.0262 (15) | 0.0358 (17) | 0.0242 (15) | 0.0025 (13) | 0.0103 (12) | 0.0054 (13) |
C10B | 0.0201 (14) | 0.0367 (16) | 0.0238 (15) | 0.0005 (12) | 0.0081 (11) | 0.0034 (13) |
C11B | 0.0200 (14) | 0.0354 (16) | 0.0250 (15) | 0.0042 (12) | 0.0063 (11) | 0.0016 (13) |
N12B | 0.0223 (12) | 0.0349 (14) | 0.0331 (14) | 0.0041 (10) | 0.0034 (11) | −0.0063 (12) |
C13B | 0.0262 (15) | 0.0354 (16) | 0.050 (2) | −0.0022 (13) | 0.0125 (14) | −0.0036 (15) |
C14B | 0.0287 (16) | 0.0427 (18) | 0.0403 (19) | 0.0037 (14) | 0.0145 (14) | 0.0035 (15) |
C15B | 0.0216 (15) | 0.0386 (16) | 0.0335 (17) | 0.0078 (12) | 0.0108 (13) | 0.0026 (13) |
C16B | 0.0277 (16) | 0.0418 (18) | 0.0347 (17) | 0.0047 (13) | 0.0101 (13) | −0.0044 (14) |
C17B | 0.0323 (17) | 0.0456 (18) | 0.0331 (18) | 0.0064 (14) | 0.0041 (14) | −0.0096 (15) |
C18B | 0.0222 (14) | 0.0410 (17) | 0.0230 (15) | 0.0004 (13) | 0.0093 (12) | −0.0011 (14) |
O18B | 0.0201 (10) | 0.0481 (12) | 0.0356 (12) | 0.0014 (9) | 0.0020 (9) | −0.0053 (10) |
N1A—C2A | 1.351 (3) | N1B—C2B | 1.360 (3) |
N1A—C9A | 1.379 (3) | N1B—C9B | 1.379 (3) |
N1A—H1A | 0.8800 | N1B—H1B | 0.8800 |
C2A—C3A | 1.388 (4) | C2B—C3B | 1.384 (4) |
C2A—H2A | 0.9500 | C2B—H2B | 0.9500 |
C3A—C10A | 1.431 (4) | C3B—C10B | 1.436 (4) |
C3A—C4A | 1.451 (3) | C3B—C4B | 1.444 (4) |
C4A—C5A | 1.391 (4) | C4B—C5B | 1.399 (4) |
C4A—C9A | 1.415 (3) | C4B—C9B | 1.408 (4) |
C5A—C6A | 1.380 (4) | C5B—C6B | 1.379 (4) |
C5A—H5A | 0.9500 | C5B—H5B | 0.9500 |
C6A—C7A | 1.402 (4) | C6B—C7B | 1.397 (5) |
C6A—H6A | 0.9500 | C6B—H6B | 0.9500 |
C7A—C8A | 1.374 (4) | C7B—C8B | 1.382 (4) |
C7A—H7A | 0.9500 | C7B—H7B | 0.9500 |
C8A—C9A | 1.390 (4) | C8B—C9B | 1.391 (4) |
C8A—H8A | 0.9500 | C8B—H8B | 0.9500 |
C10A—C11A | 1.351 (3) | C10B—C11B | 1.343 (4) |
C10A—H10A | 0.9500 | C10B—H10B | 0.9500 |
C11A—N12A | 1.446 (3) | C11B—N12B | 1.446 (4) |
C11A—C18A | 1.466 (4) | C11B—C18B | 1.477 (4) |
N12A—C17A | 1.472 (4) | N12B—C17B | 1.478 (4) |
N12A—C13A | 1.489 (3) | N12B—C13B | 1.479 (4) |
C13A—C14A | 1.554 (4) | C13B—C14B | 1.548 (4) |
C13A—H13A | 0.9900 | C13B—H13C | 0.9900 |
C13A—H13B | 0.9900 | C13B—H13D | 0.9900 |
C14A—C15A | 1.529 (4) | C14B—C15B | 1.539 (4) |
C14A—H14A | 0.9900 | C14B—H14C | 0.9900 |
C14A—H14B | 0.9900 | C14B—H14D | 0.9900 |
C15A—C18A | 1.512 (3) | C15B—C18B | 1.515 (4) |
C15A—C16A | 1.536 (4) | C15B—C16B | 1.531 (4) |
C15A—H15A | 1.0000 | C15B—H15B | 1.0000 |
C16A—C17A | 1.545 (4) | C16B—C17B | 1.556 (4) |
C16A—H16A | 0.9900 | C16B—H16C | 0.9900 |
C16A—H16B | 0.9900 | C16B—H16D | 0.9900 |
C17A—H17A | 0.9900 | C17B—H17C | 0.9900 |
C17A—H17B | 0.9900 | C17B—H17D | 0.9900 |
C18A—O18A | 1.236 (3) | C18B—O18B | 1.224 (3) |
C2A—N1A—C9A | 109.7 (2) | C2B—N1B—C9B | 109.3 (2) |
C2A—N1A—H1A | 125.2 | C2B—N1B—H1B | 125.3 |
C9A—N1A—H1A | 125.2 | C9B—N1B—H1B | 125.3 |
N1A—C2A—C3A | 110.5 (2) | N1B—C2B—C3B | 110.3 (2) |
N1A—C2A—H2A | 124.8 | N1B—C2B—H2B | 124.9 |
C3A—C2A—H2A | 124.8 | C3B—C2B—H2B | 124.9 |
C2A—C3A—C10A | 128.2 (2) | C2B—C3B—C10B | 129.5 (3) |
C2A—C3A—C4A | 105.6 (2) | C2B—C3B—C4B | 105.6 (2) |
C10A—C3A—C4A | 126.1 (2) | C10B—C3B—C4B | 124.8 (2) |
C5A—C4A—C9A | 118.2 (2) | C5B—C4B—C9B | 119.0 (3) |
C5A—C4A—C3A | 135.1 (2) | C5B—C4B—C3B | 133.7 (3) |
C9A—C4A—C3A | 106.7 (2) | C9B—C4B—C3B | 107.3 (2) |
C6A—C5A—C4A | 119.7 (3) | C6B—C5B—C4B | 118.8 (3) |
C6A—C5A—H5A | 120.1 | C6B—C5B—H5B | 120.6 |
C4A—C5A—H5A | 120.1 | C4B—C5B—H5B | 120.6 |
C5A—C6A—C7A | 120.7 (3) | C5B—C6B—C7B | 121.3 (3) |
C5A—C6A—H6A | 119.6 | C5B—C6B—H6B | 119.3 |
C7A—C6A—H6A | 119.6 | C7B—C6B—H6B | 119.3 |
C8A—C7A—C6A | 121.3 (3) | C8B—C7B—C6B | 121.2 (3) |
C8A—C7A—H7A | 119.4 | C8B—C7B—H7B | 119.4 |
C6A—C7A—H7A | 119.4 | C6B—C7B—H7B | 119.4 |
C7A—C8A—C9A | 117.6 (3) | C7B—C8B—C9B | 117.5 (3) |
C7A—C8A—H8A | 121.2 | C7B—C8B—H8B | 121.3 |
C9A—C8A—H8A | 121.2 | C9B—C8B—H8B | 121.3 |
N1A—C9A—C8A | 130.0 (2) | N1B—C9B—C8B | 130.3 (3) |
N1A—C9A—C4A | 107.6 (2) | N1B—C9B—C4B | 107.5 (2) |
C8A—C9A—C4A | 122.5 (2) | C8B—C9B—C4B | 122.2 (3) |
C11A—C10A—C3A | 128.8 (2) | C11B—C10B—C3B | 129.3 (3) |
C11A—C10A—H10A | 115.6 | C11B—C10B—H10B | 115.4 |
C3A—C10A—H10A | 115.6 | C3B—C10B—H10B | 115.4 |
C10A—C11A—N12A | 123.9 (2) | C10B—C11B—N12B | 124.0 (2) |
C10A—C11A—C18A | 122.3 (2) | C10B—C11B—C18B | 121.7 (3) |
N12A—C11A—C18A | 113.6 (2) | N12B—C11B—C18B | 114.1 (2) |
C11A—N12A—C17A | 107.9 (2) | C11B—N12B—C17B | 108.4 (2) |
C11A—N12A—C13A | 108.5 (2) | C11B—N12B—C13B | 107.8 (2) |
C17A—N12A—C13A | 108.6 (2) | C17B—N12B—C13B | 108.7 (2) |
N12A—C13A—C14A | 111.3 (2) | N12B—C13B—C14B | 111.9 (2) |
N12A—C13A—H13A | 109.4 | N12B—C13B—H13C | 109.2 |
C14A—C13A—H13A | 109.4 | C14B—C13B—H13C | 109.2 |
N12A—C13A—H13B | 109.4 | N12B—C13B—H13D | 109.2 |
C14A—C13A—H13B | 109.4 | C14B—C13B—H13D | 109.2 |
H13A—C13A—H13B | 108.0 | H13C—C13B—H13D | 107.9 |
C15A—C14A—C13A | 108.5 (2) | C15B—C14B—C13B | 108.6 (2) |
C15A—C14A—H14A | 110.0 | C15B—C14B—H14C | 110.0 |
C13A—C14A—H14A | 110.0 | C13B—C14B—H14C | 110.0 |
C15A—C14A—H14B | 110.0 | C15B—C14B—H14D | 110.0 |
C13A—C14A—H14B | 110.0 | C13B—C14B—H14D | 110.0 |
H14A—C14A—H14B | 108.4 | H14C—C14B—H14D | 108.3 |
C18A—C15A—C14A | 107.5 (2) | C18B—C15B—C16B | 106.7 (2) |
C18A—C15A—C16A | 108.1 (2) | C18B—C15B—C14B | 108.4 (2) |
C14A—C15A—C16A | 108.5 (2) | C16B—C15B—C14B | 108.3 (2) |
C18A—C15A—H15A | 110.9 | C18B—C15B—H15B | 111.1 |
C14A—C15A—H15A | 110.9 | C16B—C15B—H15B | 111.1 |
C16A—C15A—H15A | 110.9 | C14B—C15B—H15B | 111.1 |
C15A—C16A—C17A | 107.8 (2) | C15B—C16B—C17B | 108.5 (2) |
C15A—C16A—H16A | 110.2 | C15B—C16B—H16C | 110.0 |
C17A—C16A—H16A | 110.2 | C17B—C16B—H16C | 110.0 |
C15A—C16A—H16B | 110.2 | C15B—C16B—H16D | 110.0 |
C17A—C16A—H16B | 110.2 | C17B—C16B—H16D | 110.0 |
H16A—C16A—H16B | 108.5 | H16C—C16B—H16D | 108.4 |
N12A—C17A—C16A | 112.6 (2) | N12B—C17B—C16B | 111.8 (2) |
N12A—C17A—H17A | 109.1 | N12B—C17B—H17C | 109.3 |
C16A—C17A—H17A | 109.1 | C16B—C17B—H17C | 109.3 |
N12A—C17A—H17B | 109.1 | N12B—C17B—H17D | 109.3 |
C16A—C17A—H17B | 109.1 | C16B—C17B—H17D | 109.3 |
H17A—C17A—H17B | 107.8 | H17C—C17B—H17D | 107.9 |
O18A—C18A—C11A | 124.9 (2) | O18B—C18B—C11B | 125.2 (3) |
O18A—C18A—C15A | 124.3 (2) | O18B—C18B—C15B | 124.6 (3) |
C11A—C18A—C15A | 110.7 (2) | C11B—C18B—C15B | 110.2 (2) |
C9A—N1A—C2A—C3A | 0.2 (3) | C9B—N1B—C2B—C3B | 0.6 (3) |
N1A—C2A—C3A—C10A | 176.6 (2) | N1B—C2B—C3B—C10B | 176.4 (3) |
N1A—C2A—C3A—C4A | −0.7 (3) | N1B—C2B—C3B—C4B | −1.0 (3) |
C2A—C3A—C4A—C5A | −178.4 (3) | C2B—C3B—C4B—C5B | −177.7 (3) |
C10A—C3A—C4A—C5A | 4.2 (5) | C10B—C3B—C4B—C5B | 4.7 (5) |
C2A—C3A—C4A—C9A | 1.0 (3) | C2B—C3B—C4B—C9B | 1.0 (3) |
C10A—C3A—C4A—C9A | −176.4 (2) | C10B—C3B—C4B—C9B | −176.6 (2) |
C9A—C4A—C5A—C6A | 0.6 (4) | C9B—C4B—C5B—C6B | 0.2 (4) |
C3A—C4A—C5A—C6A | 179.9 (3) | C3B—C4B—C5B—C6B | 178.8 (3) |
C4A—C5A—C6A—C7A | 0.1 (4) | C4B—C5B—C6B—C7B | 1.3 (5) |
C5A—C6A—C7A—C8A | 0.1 (4) | C5B—C6B—C7B—C8B | −1.4 (5) |
C6A—C7A—C8A—C9A | −1.0 (4) | C6B—C7B—C8B—C9B | −0.1 (4) |
C2A—N1A—C9A—C8A | −179.4 (3) | C2B—N1B—C9B—C8B | 180.0 (3) |
C2A—N1A—C9A—C4A | 0.5 (3) | C2B—N1B—C9B—C4B | 0.1 (3) |
C7A—C8A—C9A—N1A | −178.4 (3) | C7B—C8B—C9B—N1B | −178.3 (3) |
C7A—C8A—C9A—C4A | 1.7 (4) | C7B—C8B—C9B—C4B | 1.6 (4) |
C5A—C4A—C9A—N1A | 178.6 (2) | C5B—C4B—C9B—N1B | 178.3 (2) |
C3A—C4A—C9A—N1A | −0.9 (3) | C3B—C4B—C9B—N1B | −0.7 (3) |
C5A—C4A—C9A—C8A | −1.5 (4) | C5B—C4B—C9B—C8B | −1.6 (4) |
C3A—C4A—C9A—C8A | 179.0 (2) | C3B—C4B—C9B—C8B | 179.4 (3) |
C2A—C3A—C10A—C11A | −1.8 (5) | C2B—C3B—C10B—C11B | 2.4 (5) |
C4A—C3A—C10A—C11A | 175.0 (3) | C4B—C3B—C10B—C11B | 179.4 (3) |
C3A—C10A—C11A—N12A | 2.0 (4) | C3B—C10B—C11B—N12B | 2.1 (5) |
C3A—C10A—C11A—C18A | −173.1 (3) | C3B—C10B—C11B—C18B | −172.9 (3) |
C10A—C11A—N12A—C17A | −115.5 (3) | C10B—C11B—N12B—C17B | 127.4 (3) |
C18A—C11A—N12A—C17A | 60.0 (3) | C18B—C11B—N12B—C17B | −57.3 (3) |
C10A—C11A—N12A—C13A | 127.0 (3) | C10B—C11B—N12B—C13B | −115.1 (3) |
C18A—C11A—N12A—C13A | −57.4 (3) | C18B—C11B—N12B—C13B | 60.2 (3) |
C11A—N12A—C13A—C14A | 58.4 (3) | C11B—N12B—C13B—C14B | −58.1 (3) |
C17A—N12A—C13A—C14A | −58.6 (3) | C17B—N12B—C13B—C14B | 59.1 (3) |
N12A—C13A—C14A—C15A | −1.1 (3) | N12B—C13B—C14B—C15B | 0.6 (3) |
C13A—C14A—C15A—C18A | −56.3 (3) | C13B—C14B—C15B—C18B | 56.0 (3) |
C13A—C14A—C15A—C16A | 60.3 (3) | C13B—C14B—C15B—C16B | −59.4 (3) |
C18A—C15A—C16A—C17A | 56.9 (3) | C18B—C15B—C16B—C17B | −58.0 (3) |
C14A—C15A—C16A—C17A | −59.3 (3) | C14B—C15B—C16B—C17B | 58.6 (3) |
C11A—N12A—C17A—C16A | −57.5 (3) | C11B—N12B—C17B—C16B | 57.0 (3) |
C13A—N12A—C17A—C16A | 59.9 (3) | C13B—N12B—C17B—C16B | −59.9 (3) |
C15A—C16A—C17A—N12A | −0.7 (3) | C15B—C16B—C17B—N12B | 0.6 (3) |
C10A—C11A—C18A—O18A | −6.3 (4) | C10B—C11B—C18B—O18B | −6.2 (4) |
N12A—C11A—C18A—O18A | 178.1 (2) | N12B—C11B—C18B—O18B | 178.4 (3) |
C10A—C11A—C18A—C15A | 173.4 (2) | C10B—C11B—C18B—C15B | 173.3 (3) |
N12A—C11A—C18A—C15A | −2.2 (3) | N12B—C11B—C18B—C15B | −2.1 (3) |
C14A—C15A—C18A—O18A | −120.3 (3) | C16B—C15B—C18B—O18B | −120.3 (3) |
C16A—C15A—C18A—O18A | 122.8 (3) | C14B—C15B—C18B—O18B | 123.2 (3) |
C14A—C15A—C18A—C11A | 59.9 (3) | C16B—C15B—C18B—C11B | 60.1 (3) |
C16A—C15A—C18A—C11A | −56.9 (3) | C14B—C15B—C18B—C11B | −56.4 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H1A···O18Ai | 0.88 | 1.94 | 2.812 (3) | 174 |
N1B—H1B···O18Bii | 0.88 | 2.01 | 2.872 (3) | 166 |
Symmetry codes: (i) x+1, −y+1, z−1/2; (ii) x−3/2, −y+3/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C16H16N2O |
Mr | 252.31 |
Crystal system, space group | Monoclinic, Cc |
Temperature (K) | 173 |
a, b, c (Å) | 6.1800 (12), 44.160 (9), 9.774 (2) |
β (°) | 108.26 (3) |
V (Å3) | 2533.1 (10) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.25 × 0.14 × 0.05 |
Data collection | |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | Multi-scan SCALEPACK (Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.979, 0.996 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 28160, 2906, 2589 |
Rint | 0.038 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.048, 0.080, 1.12 |
No. of reflections | 2906 |
No. of parameters | 344 |
No. of restraints | 2 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.21, −0.17 |
Computer programs: COLLECT (Nonius, 1999), SCALEPACK (Otwinowski & Minor, 1997), DENZO–SMN (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 1997), XP in SHELXTL/PC (Sheldrick, 1995), SHELXL97 (Sheldrick, 1997) and local procedures.
C2A—C3A | 1.388 (4) | C2B—C3B | 1.384 (4) |
C3A—C10A | 1.431 (4) | C3B—C10B | 1.436 (4) |
C10A—C11A | 1.351 (3) | C10B—C11B | 1.343 (4) |
C11A—C18A | 1.466 (4) | C11B—C18B | 1.477 (4) |
C18A—O18A | 1.236 (3) | C18B—O18B | 1.224 (3) |
C2A—C3A—C10A | 128.2 (2) | C2B—C3B—C10B | 129.5 (3) |
C11A—C10A—C3A | 128.8 (2) | C11B—C10B—C3B | 129.3 (3) |
C10A—C11A—N12A | 123.9 (2) | C10B—C11B—N12B | 124.0 (2) |
C10A—C11A—C18A | 122.3 (2) | C10B—C11B—C18B | 121.7 (3) |
N12A—C11A—C18A | 113.6 (2) | N12B—C11B—C18B | 114.1 (2) |
N12A—C17A—C16A | 112.6 (2) | N12B—C17B—C16B | 111.8 (2) |
C2A—C3A—C10A—C11A | −1.8 (5) | C2B—C3B—C10B—C11B | 2.4 (5) |
C10A—C11A—C18A—O18A | −6.3 (4) | C10B—C11B—C18B—O18B | −6.2 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1A—H1A···O18Ai | 0.88 | 1.94 | 2.812 (3) | 174.0 |
N1B—H1B···O18Bii | 0.88 | 2.01 | 2.872 (3) | 166.4 |
Symmetry codes: (i) x+1, −y+1, z−1/2; (ii) x−3/2, −y+3/2, z−1/2. |
Indole analogues, especially tryptamine derivatives, have been found to be polyamine site antagonists at the N-methyl-D-aspartate receptor (NMDAR; Worthen et al., 2001). As part of our synthetic strategy to design rigid analogues of tryptamine (Sonar et al., 2003), we focused on the synthesis of 2-(1H-indol-3-ylmethylene)-1-aza-bicyclo[2.2.2]octane, (II), from the reductive deoxygenation of the title compound. However, it was not possible to prepare N-unsubstituted analogues by base-catalyzed reaction of indole-3-carboxaldehyde, (III), with 1-aza-bicyclo[2.2.2]octan-3-one, (IV). The electron-withdrawing effect of the aldehyde group causes the N-bound H atom of (III) to become more acidic (pKa 12) than indole itself (pKa 17). Consequently, (III) forms an anion in the presence of a base, even under mild conditions, and delocalization of the negative charge on the N atom results in considerable reduction of the aldehyde character and hence in a loss of reactivity. The title compound was prepared by condensation of 1-acetylindole-3-carboxaldeyde with (IV) under base catalysis, to afford a single geometric isomer of 2-(1-acetyl-1H-indol-3-ylmethylene)-1-aza-bicyclo[2.2.2]octan-3-one. Subsequent cleavage of the 1-acetyl group afforded an isomerically pure compound, (I), which was identified by NMR spectroscopy and tentatively assigned as the Z-isomer. This azabicyclic analogue is a key intermediate in the synthesis of (II). Confirmation of the double-bond geometry in (I) is important, since this geometry will be maintained in the subsequent deoxygenated target molecule derived from this intermediate, and thus will be of value in structure–activity analysis. In order to confirm the geometry of the double bond in (I), an X-ray structure determination has been carried out and the results are presented below.
In the asymmetric unit there are two crystallographically independent molecules, and their geometries are nearly identical. An ellipsoid plot of molecule (IA) is shown in Fig. 1, and selected geometric parameters are presented in Table 1. The molecule contains a double bond that connects a 1-aza-bicyclo[2.2.2]octan-3-one ring system to a indol-3-ylmethylene group between atoms C10 and C11; geometric isomerism about this double bond affords the possibility of E– and Z-isomers. In the Z-isomer, the C11—C18 bond is in a trans position with respect to the C3—C10 bond. The double bond has a essentially planar atomic arrangement, since the r.m.s. deviation from the best plane passing through atoms N12A, C11A, C18A, C10A and C3A is 0.031 (15) Å. Deviations from the ideal geometry are observed in the bond angles around atoms C3A, C10A, C11A and C18A. While the C10A—C11A—C18A angle [122.3 (2)°] is close to ideal (120°), the C2A—C3A—C10A, C3A—C10A—C11A, N12A—C11A—C18A, N12A—C13A—C14A, N12A—C17A—C16A, C10—C11—N12A, O18A—C18A—C11A, and O18A—C18A—C15A angles are more distorted as a consequence of the strain induced by the double-bond linkage at C10A=C11A and C18A=O18A. These deviations in angles contribute to the relief of the intramolecular non-bonded interactions of the 1-azabicyclo[2.2.2]octane moiety, which is caused by the effect of the C10A=C11A and C18A=O18A double bonds on the bicyclic system. In both cases, sp2 C atoms replace sp3 C atoms, and as a result, atoms N12A, C11A, C18A, and C15A assume an almost planar configuration [N12A—C11A—C18A—C15A = −2.2 (3)°] with partial conjugation between the double bond and the carbonyl bond, as indicated by the significant shortening of the C11A—C18A single bond [1.466 (4) Å]. The bond angles for atoms C14A, C15A, C16A and N12A are on average slightly smaller than the ideal tetrahedral value, while those for atoms C13A and C17A are on average larger than the tetrahedral value, and the bond angles on the sp2 C3A, C10A, C11A and C18A atoms show values larger than the ideal value. As expected, the indole ring itself is essentially planar.
The mode of packing of (IA) and (IB) in stereo-projection along the a direction is illustrated in Fig. 2. In addition to van der Waals forces, intermolecular hydrogen bonding contributes to the stabilization of the crystal structure. There are two types of intermolecular N1—H···O18 hydrogen bonds, viz. one involving only A molecules and the other only B molecules (Table 2). No π–π interaction was observed.