Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101010770/sk1492sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101010770/sk1492Isup2.hkl |
CCDC reference: 173392
To a stirred solution of α-diazoester 1 (140 mg, 0.38 mmol) in dry benzene under an argon atmosphere at ambient temperature, a catalytic amount of Rh2(OAc)4 was added. After stirring the mixture for 24 h, the solvent was removed in vacuo and the residue was purified by flash chromatography (alumina, ethyl acetate/petroleum ether 20:80). Recrystallization from a dichloromethane:diethyl ether:petroleum ether (3:3:1) solution afforded 80 mg (62%) of (I) as yellowish-green crystals.
After checking their presence in the difference map, all H atoms were geometrically fixed and allowed to ride on their attached atoms, with C—H = 0.93–0.97 Å and O—H = 0.82 Å, and Uiso(H) = 1.5Ueq(O) and 1.2Ueq(C). Query.
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, PARST95 (Nardelli, 1995) and PLATON (Spek, 1990).
Fig. 1. The molecular structure of (I) showing 30% probability displacement ellipsoids and the atom-numbering scheme. H atoms are drawn as small spheres of arbitrary radii. |
C16H19ClN2O4 | F(000) = 356 |
Mr = 338.78 | Dx = 1.330 Mg m−3 |
Triclinic, P1 | Melting point: 426K K |
a = 9.2081 (4) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 9.4835 (4) Å | Cell parameters from 3323 reflections |
c = 11.1287 (6) Å | θ = 2.0–28.3° |
α = 100.574 (1)° | µ = 0.25 mm−1 |
β = 101.751 (1)° | T = 293 K |
γ = 111.882 (1)° | Slab, yellowish green |
V = 846.14 (7) Å3 | 0.46 × 0.36 × 0.22 mm |
Z = 2 |
Siemens SMART CCD area-detector diffractometer | 3990 independent reflections |
Radiation source: fine-focus sealed tube | 2299 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.057 |
Detector resolution: 8.33 pixels mm-1 | θmax = 28.2°, θmin = 2.0° |
ω scans | h = −12→12 |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | k = −12→12 |
Tmin = 0.895, Tmax = 0.948 | l = −12→14 |
6088 measured reflections |
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)] = 0.076 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.209 | H-atom parameters constrained |
S = 0.94 | w = 1/[σ2(Fo2) + (0.1071P)2] where P = (Fo2 + 2Fc2)/3 |
3990 reflections | (Δ/σ)max < 0.001 |
212 parameters | Δρmax = 0.63 e Å−3 |
2 restraints | Δρmin = −0.62 e Å−3 |
C16H19ClN2O4 | γ = 111.882 (1)° |
Mr = 338.78 | V = 846.14 (7) Å3 |
Triclinic, P1 | Z = 2 |
a = 9.2081 (4) Å | Mo Kα radiation |
b = 9.4835 (4) Å | µ = 0.25 mm−1 |
c = 11.1287 (6) Å | T = 293 K |
α = 100.574 (1)° | 0.46 × 0.36 × 0.22 mm |
β = 101.751 (1)° |
Siemens SMART CCD area-detector diffractometer | 3990 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | 2299 reflections with I > 2σ(I) |
Tmin = 0.895, Tmax = 0.948 | Rint = 0.057 |
6088 measured reflections |
R[F2 > 2σ(F2)] = 0.076 | 2 restraints |
wR(F2) = 0.209 | H-atom parameters constrained |
S = 0.94 | Δρmax = 0.63 e Å−3 |
3990 reflections | Δρmin = −0.62 e Å−3 |
212 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Cl1 | 0.45819 (11) | 0.21311 (9) | 0.18714 (8) | 0.0550 (3) | |
O1 | 0.3028 (2) | 0.7970 (3) | 0.3657 (2) | 0.0503 (6) | |
H1A | 0.3411 | 0.8839 | 0.4188 | 0.075* | |
O2 | −0.0171 (3) | 0.3112 (3) | 0.0170 (2) | 0.0575 (6) | |
O3 | 0.5669 (3) | 0.8382 (2) | 0.2006 (2) | 0.0521 (6) | |
O4 | 0.6409 (3) | 1.0135 (3) | 0.3897 (2) | 0.0564 (7) | |
N1 | 0.2167 (3) | 0.2805 (3) | 0.0998 (2) | 0.0391 (6) | |
N2 | 0.7440 (3) | 0.5413 (3) | 0.3051 (3) | 0.0481 (7) | |
C1 | 0.3702 (4) | 0.3479 (3) | 0.1796 (3) | 0.0362 (6) | |
C2 | 0.4532 (3) | 0.5035 (3) | 0.2557 (3) | 0.0323 (6) | |
C3 | 0.6239 (3) | 0.5831 (3) | 0.3428 (3) | 0.0361 (6) | |
C4 | 0.9080 (5) | 0.6318 (8) | 0.3933 (5) | 0.108 (2) | |
H4A | 0.9669 | 0.5658 | 0.3879 | 0.130* | |
H4B | 0.9632 | 0.7219 | 0.3640 | 0.130* | |
C5 | 0.9225 (6) | 0.6899 (9) | 0.5249 (5) | 0.149 (3) | |
H5A | 1.0357 | 0.7648 | 0.5682 | 0.179* | |
H5B | 0.9002 | 0.6015 | 0.5614 | 0.179* | |
C6 | 0.8205 (4) | 0.7653 (5) | 0.5543 (4) | 0.0600 (10) | |
H6A | 0.8735 | 0.8766 | 0.5587 | 0.072* | |
H6B | 0.8065 | 0.7587 | 0.6374 | 0.072* | |
C7 | 0.6541 (3) | 0.6888 (3) | 0.4544 (3) | 0.0372 (7) | |
C8 | 0.5202 (4) | 0.7338 (4) | 0.4785 (3) | 0.0398 (7) | |
H8A | 0.5668 | 0.8331 | 0.5459 | 0.048* | |
H8B | 0.4444 | 0.6526 | 0.5056 | 0.048* | |
C9 | 0.4305 (3) | 0.7510 (3) | 0.3549 (3) | 0.0362 (7) | |
C10 | 0.3563 (3) | 0.5894 (3) | 0.2559 (3) | 0.0315 (6) | |
C11 | 0.1993 (4) | 0.5246 (4) | 0.1770 (3) | 0.0401 (7) | |
H11A | 0.1362 | 0.5816 | 0.1761 | 0.048* | |
C12 | 0.1361 (3) | 0.3693 (4) | 0.0974 (3) | 0.0392 (7) | |
C13 | 0.7499 (5) | 0.5374 (5) | 0.1754 (4) | 0.0674 (11) | |
H13A | 0.8091 | 0.4777 | 0.1515 | 0.101* | |
H13B | 0.8043 | 0.6437 | 0.1708 | 0.101* | |
H13C | 0.6404 | 0.4883 | 0.1179 | 0.101* | |
C14 | 0.5584 (4) | 0.8815 (3) | 0.3185 (3) | 0.0375 (7) | |
C15 | 0.6896 (6) | 0.9556 (5) | 0.1650 (4) | 0.0739 (12) | |
H15A | 0.6901 | 0.9110 | 0.0805 | 0.111* | |
H15B | 0.7954 | 0.9884 | 0.2247 | 0.111* | |
H15C | 0.6650 | 1.0456 | 0.1663 | 0.111* | |
C16 | −0.0894 (5) | 0.1510 (4) | −0.0618 (4) | 0.0714 (12) | |
H16A | −0.1965 | 0.1265 | −0.1155 | 0.107* | |
H16B | −0.0984 | 0.0810 | −0.0086 | 0.107* | |
H16C | −0.0219 | 0.1379 | −0.1142 | 0.107* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0605 (6) | 0.0455 (5) | 0.0550 (5) | 0.0324 (4) | 0.0027 (4) | 0.0000 (4) |
O1 | 0.0399 (12) | 0.0559 (13) | 0.0524 (14) | 0.0288 (11) | 0.0101 (10) | −0.0046 (11) |
O2 | 0.0366 (12) | 0.0470 (13) | 0.0606 (15) | 0.0086 (11) | −0.0128 (11) | 0.0016 (12) |
O3 | 0.0679 (15) | 0.0448 (12) | 0.0315 (12) | 0.0122 (11) | 0.0191 (11) | 0.0043 (10) |
O4 | 0.0703 (16) | 0.0379 (12) | 0.0477 (14) | 0.0123 (12) | 0.0257 (13) | −0.0042 (11) |
N1 | 0.0363 (14) | 0.0359 (13) | 0.0331 (13) | 0.0101 (11) | 0.0022 (11) | 0.0029 (11) |
N2 | 0.0299 (13) | 0.0573 (16) | 0.0555 (17) | 0.0235 (13) | 0.0066 (12) | 0.0089 (14) |
C1 | 0.0380 (16) | 0.0395 (16) | 0.0313 (15) | 0.0188 (14) | 0.0098 (13) | 0.0060 (13) |
C2 | 0.0310 (15) | 0.0369 (15) | 0.0265 (14) | 0.0137 (12) | 0.0079 (11) | 0.0059 (12) |
C3 | 0.0298 (15) | 0.0398 (16) | 0.0372 (16) | 0.0155 (13) | 0.0062 (12) | 0.0109 (13) |
C4 | 0.044 (2) | 0.158 (5) | 0.109 (4) | 0.061 (3) | −0.002 (3) | −0.006 (4) |
C5 | 0.052 (3) | 0.231 (8) | 0.113 (5) | 0.076 (4) | −0.029 (3) | −0.041 (5) |
C6 | 0.0373 (19) | 0.068 (2) | 0.051 (2) | 0.0119 (18) | −0.0048 (16) | 0.0042 (18) |
C7 | 0.0302 (15) | 0.0411 (16) | 0.0306 (15) | 0.0094 (13) | 0.0028 (12) | 0.0078 (13) |
C8 | 0.0418 (17) | 0.0426 (17) | 0.0276 (15) | 0.0138 (14) | 0.0092 (13) | 0.0037 (13) |
C9 | 0.0316 (15) | 0.0411 (16) | 0.0328 (15) | 0.0173 (13) | 0.0082 (12) | 0.0013 (13) |
C10 | 0.0270 (14) | 0.0334 (14) | 0.0286 (14) | 0.0108 (12) | 0.0065 (11) | 0.0029 (11) |
C11 | 0.0320 (15) | 0.0415 (16) | 0.0411 (17) | 0.0167 (13) | 0.0045 (13) | 0.0040 (14) |
C12 | 0.0260 (15) | 0.0419 (17) | 0.0378 (16) | 0.0066 (13) | 0.0030 (12) | 0.0086 (14) |
C13 | 0.060 (2) | 0.089 (3) | 0.072 (3) | 0.040 (2) | 0.040 (2) | 0.026 (2) |
C14 | 0.0399 (16) | 0.0383 (16) | 0.0356 (16) | 0.0211 (14) | 0.0090 (13) | 0.0066 (14) |
C15 | 0.098 (3) | 0.060 (2) | 0.059 (2) | 0.019 (2) | 0.047 (2) | 0.015 (2) |
C16 | 0.050 (2) | 0.045 (2) | 0.077 (3) | −0.0012 (18) | −0.016 (2) | 0.009 (2) |
Cl1—C1 | 1.755 (3) | C5—H5B | 0.9700 |
O1—C9 | 1.417 (3) | C6—C7 | 1.514 (4) |
O1—H1A | 0.8200 | C6—H6A | 0.9700 |
O2—C12 | 1.348 (3) | C6—H6B | 0.9700 |
O2—C16 | 1.428 (4) | C7—C8 | 1.503 (4) |
O3—C14 | 1.329 (3) | C8—C9 | 1.524 (4) |
O3—C15 | 1.442 (4) | C8—H8A | 0.9700 |
O4—C14 | 1.206 (3) | C8—H8B | 0.9700 |
N1—C12 | 1.314 (4) | C9—C10 | 1.524 (4) |
N1—C1 | 1.343 (4) | C9—C14 | 1.541 (4) |
N2—C3 | 1.418 (4) | C10—C11 | 1.364 (4) |
N2—C4 | 1.450 (5) | C11—C12 | 1.402 (4) |
N2—C13 | 1.451 (5) | C11—H11A | 0.9300 |
C1—C2 | 1.385 (4) | C13—H13A | 0.9600 |
C2—C10 | 1.415 (4) | C13—H13B | 0.9600 |
C2—C3 | 1.485 (4) | C13—H13C | 0.9600 |
C3—C7 | 1.349 (4) | C15—H15A | 0.9600 |
C4—C5 | 1.426 (4) | C15—H15B | 0.9600 |
C4—H4A | 0.9700 | C15—H15C | 0.9600 |
C4—H4B | 0.9700 | C16—H16A | 0.9600 |
C5—C6 | 1.429 (4) | C16—H16B | 0.9600 |
C5—H5A | 0.9700 | C16—H16C | 0.9600 |
C9—O1—H1A | 109.5 | C7—C8—H8B | 110.0 |
C12—O2—C16 | 118.4 (3) | C9—C8—H8B | 110.0 |
C14—O3—C15 | 115.9 (3) | H8A—C8—H8B | 108.4 |
C12—N1—C1 | 116.7 (2) | O1—C9—C8 | 114.1 (2) |
C3—N2—C4 | 113.9 (3) | O1—C9—C10 | 108.4 (2) |
C3—N2—C13 | 116.8 (3) | C8—C9—C10 | 106.8 (2) |
C4—N2—C13 | 109.3 (3) | O1—C9—C14 | 107.7 (2) |
N1—C1—C2 | 126.0 (3) | C8—C9—C14 | 106.9 (2) |
N1—C1—Cl1 | 112.8 (2) | C10—C9—C14 | 113.2 (2) |
C2—C1—Cl1 | 121.1 (2) | C11—C10—C2 | 121.0 (3) |
C1—C2—C10 | 114.3 (2) | C11—C10—C9 | 121.9 (2) |
C1—C2—C3 | 127.6 (3) | C2—C10—C9 | 116.9 (2) |
C10—C2—C3 | 117.9 (2) | C10—C11—C12 | 117.9 (3) |
C7—C3—N2 | 124.0 (3) | C10—C11—H11A | 121.0 |
C7—C3—C2 | 117.7 (2) | C12—C11—H11A | 121.0 |
N2—C3—C2 | 118.3 (2) | N1—C12—O2 | 120.1 (3) |
C5—C4—N2 | 117.4 (4) | N1—C12—C11 | 123.5 (3) |
C5—C4—H4A | 108.0 | O2—C12—C11 | 116.4 (3) |
N2—C4—H4A | 108.0 | N2—C13—H13A | 109.5 |
C5—C4—H4B | 108.0 | N2—C13—H13B | 109.5 |
N2—C4—H4B | 108.0 | H13A—C13—H13B | 109.5 |
H4A—C4—H4B | 107.2 | N2—C13—H13C | 109.5 |
C4—C5—C6 | 117.8 (5) | H13A—C13—H13C | 109.5 |
C4—C5—H5A | 107.9 | H13B—C13—H13C | 109.5 |
C6—C5—H5A | 107.9 | O4—C14—O3 | 122.6 (3) |
C4—C5—H5B | 107.9 | O4—C14—C9 | 122.9 (3) |
C6—C5—H5B | 107.9 | O3—C14—C9 | 114.5 (2) |
H5A—C5—H5B | 107.2 | O3—C15—H15A | 109.5 |
C5—C6—C7 | 111.4 (3) | O3—C15—H15B | 109.5 |
C5—C6—H6A | 109.3 | H15A—C15—H15B | 109.5 |
C7—C6—H6A | 109.3 | O3—C15—H15C | 109.5 |
C5—C6—H6B | 109.3 | H15A—C15—H15C | 109.5 |
C7—C6—H6B | 109.3 | H15B—C15—H15C | 109.5 |
H6A—C6—H6B | 108.0 | O2—C16—H16A | 109.5 |
C3—C7—C8 | 119.0 (3) | O2—C16—H16B | 109.5 |
C3—C7—C6 | 121.5 (3) | H16A—C16—H16B | 109.5 |
C8—C7—C6 | 119.5 (3) | O2—C16—H16C | 109.5 |
C7—C8—C9 | 108.4 (2) | H16A—C16—H16C | 109.5 |
C7—C8—H8A | 110.0 | H16B—C16—H16C | 109.5 |
C9—C8—H8A | 110.0 | ||
C12—N1—C1—C2 | −2.6 (4) | C7—C8—C9—C14 | −59.7 (3) |
C12—N1—C1—Cl1 | 173.8 (2) | C1—C2—C10—C11 | −5.8 (4) |
N1—C1—C2—C10 | 6.8 (4) | C3—C2—C10—C11 | 179.1 (3) |
Cl1—C1—C2—C10 | −169.3 (2) | C1—C2—C10—C9 | 169.5 (2) |
N1—C1—C2—C3 | −178.5 (3) | C3—C2—C10—C9 | −5.6 (4) |
Cl1—C1—C2—C3 | 5.4 (4) | O1—C9—C10—C11 | 12.0 (4) |
C4—N2—C3—C7 | −4.5 (5) | C8—C9—C10—C11 | 135.3 (3) |
C13—N2—C3—C7 | −133.5 (3) | C14—C9—C10—C11 | −107.4 (3) |
C4—N2—C3—C2 | 176.8 (4) | O1—C9—C10—C2 | −163.3 (2) |
C13—N2—C3—C2 | 47.8 (4) | C8—C9—C10—C2 | −40.0 (3) |
C1—C2—C3—C7 | −142.8 (3) | C14—C9—C10—C2 | 77.4 (3) |
C10—C2—C3—C7 | 31.6 (4) | C2—C10—C11—C12 | 1.0 (4) |
C1—C2—C3—N2 | 35.9 (4) | C9—C10—C11—C12 | −174.0 (3) |
C10—C2—C3—N2 | −149.6 (3) | C1—N1—C12—O2 | 178.1 (3) |
C3—N2—C4—C5 | 28.8 (8) | C1—N1—C12—C11 | −3.1 (4) |
C13—N2—C4—C5 | 161.4 (6) | C16—O2—C12—N1 | 1.7 (4) |
N2—C4—C5—C6 | −46.3 (10) | C16—O2—C12—C11 | −177.2 (3) |
C4—C5—C6—C7 | 35.1 (9) | C10—C11—C12—N1 | 3.8 (5) |
N2—C3—C7—C8 | 174.7 (3) | C10—C11—C12—O2 | −177.4 (3) |
C2—C3—C7—C8 | −6.6 (4) | C15—O3—C14—O4 | 4.1 (5) |
N2—C3—C7—C6 | −4.0 (5) | C15—O3—C14—C9 | −177.8 (3) |
C2—C3—C7—C6 | 174.7 (3) | O1—C9—C14—O4 | 67.0 (3) |
C5—C6—C7—C3 | −10.9 (6) | C8—C9—C14—O4 | −56.0 (3) |
C5—C6—C7—C8 | 170.4 (4) | C10—C9—C14—O4 | −173.2 (3) |
C3—C7—C8—C9 | −40.5 (4) | O1—C9—C14—O3 | −111.1 (3) |
C6—C7—C8—C9 | 138.3 (3) | C8—C9—C14—O3 | 125.9 (3) |
C7—C8—C9—O1 | −178.6 (2) | C10—C9—C14—O3 | 8.7 (3) |
C7—C8—C9—C10 | 61.6 (3) |
Experimental details
Crystal data | |
Chemical formula | C16H19ClN2O4 |
Mr | 338.78 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 9.2081 (4), 9.4835 (4), 11.1287 (6) |
α, β, γ (°) | 100.574 (1), 101.751 (1), 111.882 (1) |
V (Å3) | 846.14 (7) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.25 |
Crystal size (mm) | 0.46 × 0.36 × 0.22 |
Data collection | |
Diffractometer | Siemens SMART CCD area-detector diffractometer |
Absorption correction | Empirical (using intensity measurements) (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.895, 0.948 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6088, 3990, 2299 |
Rint | 0.057 |
(sin θ/λ)max (Å−1) | 0.666 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.076, 0.209, 0.94 |
No. of reflections | 3990 |
No. of parameters | 212 |
No. of restraints | 2 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.63, −0.62 |
Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SAINT, SHELXTL (Sheldrick, 1997), SHELXTL, PARST95 (Nardelli, 1995) and PLATON (Spek, 1990).
N1—C12 | 1.314 (4) | C3—C7 | 1.349 (4) |
N1—C1 | 1.343 (4) | C6—C7 | 1.514 (4) |
N2—C3 | 1.418 (4) | C7—C8 | 1.503 (4) |
N2—C4 | 1.450 (5) | C8—C9 | 1.524 (4) |
C2—C10 | 1.415 (4) | C9—C10 | 1.524 (4) |
C2—C3 | 1.485 (4) | ||
C3—N2—C4 | 113.9 (3) | O1—C9—C10 | 108.4 (2) |
C7—C3—N2 | 124.0 (3) | C8—C9—C10 | 106.8 (2) |
C3—C7—C8 | 119.0 (3) | O1—C9—C14 | 107.7 (2) |
C7—C8—C9 | 108.4 (2) | ||
C10—C2—C3—C7 | 31.6 (4) | C1—N1—C12—C11 | −3.1 (4) |
C1—C2—C3—N2 | 35.9 (4) | C16—O2—C12—N1 | 1.7 (4) |
C10—C2—C3—N2 | −149.6 (3) | C10—C9—C14—O4 | −173.2 (3) |
The synthesis and biological evaluation of conformationally restricted analogues of nicotine and anabasine have attracted much attention (Catka & Leete, 1978; Kanne et al., 1986; Kanne & Abood, 1988; Vernier et al., 1998). The anabasine analogue with a piperidine ring has recently been screened as one of the agonists of neuronal acetylcholine receptors (nAChRs) and, more interestingly, the anabasine analogue with a pyrrolidine ring is currently under clinical trial for the treatment of Parkinson's disease and pain (Vernier et al., 1998). In this context, Sarkar et al. (2000) recently reported a domino reaction-based flexible strategy for the synthesis of the two analogues and synthesized the title compound, (I). The presence of a methoxy group at a proper position in the pyridine ring of the bridged analogues is the key to better selectivity as nAChR agonists. An X-ray crystal-structure determination of (I) was undertaken to assist in the understanding of its properties and the results are presented here. \sch
In compound (I), the bond lengths and angles show normal values and are comparable with those of the related structure previously studied by Sarkar et al. (1999). The pyridine ring is nearly planar, with a maximum deviation of -0.039 (3) Å for C2. The chloro group deviates by 0.252 (1) Å, and the methoxy group is twisted through 2.2 (3)°, relative to the least-squares plane of the pyridine ring.
The piperidine ring is not planar, with atoms C4 and C5 deviating by 0.196 (7) and -0.223 (8) Å, respectively. The puckering parameters (Cremer & Pople, 1975) are Q2 = 0.265 (5) and Q3 = 0.188 (5) Å, ϕ2 = 260.8 (10)°, QT = 0.325 (6) Å, and θ2 = 54.7 (9)°. The methyl group, C13, deviates by 0.802 (5) Å from the least-squares plane of the piperidine ring.
The cyclohexane ring adopts a screw-boat conformation, with the following deviations of atoms from their least-squares plane: C10 - 0.071 (3), C2 - 0.202 (3), C8 - 0.365 (4), C7 0.063 (3), C3 0.212 (3) and C9 0.363 (3) Å. This is also confirmed by the puckering parameters Q2 = 0.571 (3) and Q3 = 0.182 (3) Å, ϕ2 = 210.8 (3)°, QT = 0.600 (3) Å, and θ2 = 72.3 (3)°.
The hydroxy group is in the least-squares plane through the cyclohexane ring, while this plane makes dihedral angles of 20.1 (2), 23.5 (2) and 80.9 (2)° with the least-squares planes through the pyridine ring, piperidine ring and carboxylate group, respectively.