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Acta Crystallogr Sect E Struct Rep Online. 2008 November 1; 64(Pt 11): o2174.
Published online 2008 October 22. doi:  10.1107/S1600536808033874
PMCID: PMC2959677

(±)-Cyclo­hexane-1,2-diyl bis­(4-nitro­benzoate)

Abstract

The crystal structure of the title compound, C20H18N2O8, has been investigated to establish the relative stereochemistry between the ester groups. The cyclo­hexane ring adopts a chair conformation, in which the two ester groups occupy the adjacent equatorial positions in a trans relationship with each other. The mol­ecules assemble in the crystal as chains along the c axis via C—H(...)π inter­actions between the cyclo­hexane ring and a pair of nitro­phenyl rings of the neighbouring mol­ecule. Also observed are π–π stacking inter­actions between the nitro­phenyl rings of neighbouring chains, with a perpendicular distance between these rings of 3.409 Å and a slippage of 0.969 Å.

Related literature

For the related synthesis of cyclo­hexane-1,2-diyl-bis­(4-bromo­benzoate) from trans-cyclo­hexane-1,2-diol, see: Hayashi et al. (2004 [triangle]); for non-conventional hydrogen contacts and stacking inter­actions, see: Desiraju & Steiner (2001 [triangle]) and Ciunik & Jarosz (1998 [triangle]).

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Object name is e-64-o2174-scheme1.jpg

Experimental

Crystal data

  • C20H18N2O8
  • M r = 414.36
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-o2174-efi1.jpg
  • a = 12.6510 (2) Å
  • b = 12.2720 (2) Å
  • c = 13.2186 (2) Å
  • β = 108.8300 (10)°
  • V = 1942.39 (5) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.11 mm−1
  • T = 89 (2) K
  • 0.2 × 0.1 × 0.05 mm

Data collection

  • Siemens SMART diffractometer with an APEXII CCD detector
  • Absorption correction: none
  • 15207 measured reflections
  • 4973 independent reflections
  • 2999 reflections with I > 2σ(I)
  • R int = 0.077

Refinement

  • R[F 2 > 2σ(F 2)] = 0.041
  • wR(F 2) = 0.098
  • S = 0.91
  • 4973 reflections
  • 271 parameters
  • H-atom parameters constrained
  • Δρmax = 0.28 e Å−3
  • Δρmin = −0.30 e Å−3

Data collection: SMART (Siemens, 1995 [triangle]); cell refinement: SAINT (Siemens, 1995 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 [triangle]) and Mercury (Macrae et al., 2006 [triangle]); software used to prepare material for publication: WinGX (Farrugia, 1999 [triangle]) and publCIF (Westrip, 2008 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808033874/si2117sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808033874/si2117Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

The authors thank Tania Groutso for data collection. The award of an International Doctoral Scholarship from the University of Auckland and a New Zealand International Doctoral Research Scholarship from Education New Zealand (to STT) are greatly appreciated.

supplementary crystallographic information

Comment

The title diester was isolated as a part of the study towards the organocatalytic α-oxidation of cyclohexanone catalysed by (S)-proline. Using 3-phenyl-2-tosyl-1,2-oxaziridine as the oxidant, cyclohexanone was oxidized to α-hydroxycyclohexanone which was subsequently reduced in-situ to the corresponding diol with sodium borohydride. Concomitant esterification of the two hydroxyl groups afforded the title diester.

The crystal structure reveals the relative stereochemistry of the racemic diester to be 1R*,2R* and 1S*,2S* (1R*,6R* and 1S*,6S* in the crystallographic numbering scheme, Fig. 1). The two adjacent ester groups occupy the trans diequatorial position of the cyclohexane ring in the chair conformation with a C2 rotational axis bissecting the cyclohexane ring between the two ester groups (Figure 1). The cyclohexane moiety fits into a cleft formed by the two nitrophenyl groups of a neighbouring diester of opposite stereochemistry with an interplanar angle of 89.16 (6)° (Fig. 2) and the molecules are connected to each other via C—H···π interactions and C—H···O contacts (Table 1). Weak non-conventional C—H···O and C—H···π contacts are extensively discussed by Desiraju & Steiner (2001), and a combination of C—H···O and π···π stacking interactions are reported by Ciunik & Jarosz (1998).These interactions lead to the formation of chains of molecules running along the c axis. Each chain is surrounded by four similar chains that are propagated in the opposite direction, and π···π stacking interactions are observed between the nitrophenyl groups of neighbouring chains (Fig. 3). The centroid (Cg) separation between the stacking phenyl ring (Cg2, C9–C14) and the neighbouring ring (Cg2iv), is 3.5441 (9) Å, (symmetry code iv = 1 - x, - y, 1 - z). The slippage of the two rings is 0.969 Å along the 1,4 (C9–C12) vector and the perpendicular distance between Cg2 and the second symmetry related ring is 3.409 Å.

Experimental

To a solution of cyclohexane-1,2-diol (19.0 mg, 0.164 mmol) in CH2Cl2 (1.2 ml) was added triethylamine (0.400 ml, 2.89 mmol), 4-nitrobenzoyl chloride (152 mg, 0.818 mmol) and a catalytic amount of 4-(dimethylamino)-pyridine at room temperature. After overnight stirring, the mixture was quenched with pH 7 phosphate buffer (2 ml). The organic phase was separated and the aqueous phase was extracted with EtOAc (5 ml x 3). The combined organic extracts were washed with brine, dried over MgSO4 and concentrated in vacuo to afford a crude dark brown oil. Purification by flash chromatography using hexane-EtOAc (4:1) as eluent furnished the title diester as a brown solid (64.0 mg, 94%). Recrystallization of the title diester from methanol afforded yellow needles. Melting point: 381 K.

Refinement

H atoms were placed in calculated positions and were refined using a riding model (C–H = 0.93 or 0.97 Å), with Uiso(H) = 1.2 or 1.5 times Ueq(C).

Figures

Fig. 1.
The molecular structure and atom numbering scheme of (1R*,2R*)-diester (1R*,6R* in the crystallographic numbering scheme) with displacement ellipsoids drawn at the 50% probability level for non-H atoms.
Fig. 2.
The molecular packing of racemic diester withing a unit cell. The origin of the unit cell is labelled as O while cell axes are labelled as a (red), b (green) and c (blue), respectively.
Fig. 3.
The molecular packing of racemic diester with non-conventional hydrogen bonding represented as dashed lines. Hydrogen atoms not involved in hydrogen bonding have been omitted for clarity.

Crystal data

C20H18N2O8Dx = 1.417 Mg m3
Mr = 414.36Melting point: 381(1) K
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 12.6510 (2) ÅCell parameters from 4298 reflections
b = 12.2720 (2) Åθ = 1.7–25.1°
c = 13.2186 (2) ŵ = 0.11 mm1
β = 108.830 (1)°T = 89 K
V = 1942.39 (5) Å3Needle, yellow
Z = 40.2 × 0.1 × 0.05 mm
F(000) = 864

Data collection

Siemens SMART diffractometer with an APEXII CCD detector2999 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.077
graphiteθmax = 28.8°, θmin = 1.7°
area–detector ω scansh = −16→17
15207 measured reflectionsk = −16→16
4973 independent reflectionsl = −17→17

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.098H-atom parameters constrained
S = 0.91w = 1/[σ2(Fo2) + (0.0453P)2] where P = (Fo2 + 2Fc2)/3
4973 reflections(Δ/σ)max < 0.001
271 parametersΔρmax = 0.28 e Å3
0 restraintsΔρmin = −0.30 e Å3

Special details

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)

xyzUiso*/Ueq
O20.13143 (8)0.12316 (9)0.12240 (8)0.0237 (2)
O40.07109 (9)0.29575 (9)0.08144 (8)0.0294 (3)
O10.36109 (8)0.08691 (8)0.21140 (7)0.0238 (3)
O30.26940 (8)−0.03067 (9)0.28553 (8)0.0263 (3)
O60.62313 (9)0.29785 (10)0.71389 (8)0.0337 (3)
O7−0.20229 (9)0.24599 (10)0.45414 (8)0.0341 (3)
O50.55152 (10)0.16681 (9)0.78095 (8)0.0368 (3)
O8−0.16503 (10)0.07314 (10)0.46935 (9)0.0371 (3)
C90.39653 (12)0.09399 (12)0.39838 (11)0.0213 (3)
N10.56407 (11)0.21667 (11)0.70528 (10)0.0280 (3)
N2−0.16168 (10)0.16318 (12)0.42995 (10)0.0269 (3)
C18−0.10386 (12)0.17208 (13)0.34967 (11)0.0221 (3)
C10.29657 (12)0.04900 (13)0.10370 (11)0.0224 (3)
H10.2646−0.02290.10800.027*
C120.50482 (13)0.17579 (12)0.59718 (11)0.0236 (3)
C60.20401 (12)0.13022 (13)0.05672 (11)0.0235 (3)
H60.23540.20380.06140.028*
C150.00784 (12)0.19370 (13)0.20538 (10)0.0206 (3)
C160.02556 (12)0.10200 (13)0.27072 (11)0.0238 (4)
H160.07570.04870.26550.029*
C140.35143 (13)0.07916 (13)0.48064 (12)0.0261 (4)
H140.28430.04200.46760.031*
C17−0.03163 (12)0.09018 (13)0.34374 (11)0.0247 (4)
H17−0.02150.02890.38730.030*
C100.49575 (13)0.15077 (13)0.41674 (11)0.0240 (3)
H100.52540.16030.36150.029*
C20−0.06729 (12)0.27323 (13)0.21196 (11)0.0226 (3)
H20−0.07990.33350.16690.027*
C130.40625 (13)0.11952 (13)0.58144 (12)0.0270 (4)
H130.37760.10910.63730.032*
C40.21805 (13)0.09860 (14)−0.12498 (12)0.0315 (4)
H4A0.17630.0791−0.19810.038*
H4B0.25140.1697−0.12570.038*
C110.55089 (13)0.19336 (13)0.51698 (12)0.0254 (4)
H110.61690.23260.52990.031*
C70.33501 (12)0.04317 (13)0.29358 (12)0.0225 (3)
C50.13918 (13)0.10373 (15)−0.05883 (11)0.0302 (4)
H5A0.08290.1592−0.08780.036*
H5B0.10160.0342−0.06250.036*
C80.07180 (12)0.21209 (13)0.12914 (11)0.0226 (3)
C19−0.12367 (12)0.26323 (13)0.28548 (11)0.0226 (3)
H19−0.17350.31660.29140.027*
C30.30937 (13)0.01510 (14)−0.07859 (12)0.0297 (4)
H3A0.35990.0142−0.12030.036*
H3B0.2763−0.0568−0.08260.036*
C20.37471 (12)0.04183 (14)0.03779 (11)0.0259 (4)
H2A0.4302−0.01430.06700.031*
H2B0.41340.11070.04120.031*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O20.0232 (5)0.0264 (6)0.0246 (5)0.0030 (5)0.0120 (4)0.0016 (5)
O40.0333 (6)0.0289 (6)0.0296 (6)0.0057 (6)0.0154 (5)0.0067 (5)
O10.0238 (6)0.0269 (6)0.0198 (5)−0.0028 (5)0.0057 (4)−0.0001 (5)
O30.0266 (6)0.0235 (6)0.0279 (6)−0.0040 (5)0.0077 (5)−0.0001 (5)
O60.0331 (6)0.0315 (7)0.0330 (6)−0.0044 (6)0.0057 (5)−0.0059 (6)
O70.0320 (6)0.0451 (8)0.0290 (6)0.0127 (6)0.0150 (5)0.0018 (6)
O50.0551 (8)0.0320 (7)0.0227 (6)0.0051 (6)0.0118 (5)0.0032 (5)
O80.0417 (7)0.0364 (7)0.0406 (7)−0.0056 (6)0.0236 (6)0.0053 (6)
C90.0220 (8)0.0188 (8)0.0218 (7)0.0018 (7)0.0053 (6)0.0023 (7)
N10.0317 (8)0.0258 (8)0.0247 (7)0.0069 (7)0.0065 (6)−0.0003 (6)
N20.0208 (7)0.0354 (9)0.0248 (7)−0.0002 (7)0.0078 (6)0.0009 (7)
C180.0185 (7)0.0299 (9)0.0183 (7)0.0004 (7)0.0066 (6)−0.0008 (7)
C10.0207 (8)0.0255 (9)0.0197 (7)−0.0011 (7)0.0046 (6)−0.0016 (7)
C120.0279 (8)0.0198 (8)0.0205 (7)0.0033 (7)0.0041 (6)0.0003 (7)
C60.0221 (8)0.0273 (9)0.0240 (8)0.0009 (7)0.0114 (6)0.0018 (7)
C150.0190 (7)0.0251 (8)0.0165 (7)−0.0001 (7)0.0043 (6)−0.0020 (7)
C160.0224 (8)0.0255 (9)0.0245 (8)0.0056 (7)0.0087 (6)0.0006 (7)
C140.0242 (8)0.0257 (9)0.0292 (8)−0.0031 (8)0.0098 (7)0.0003 (7)
C170.0260 (8)0.0242 (9)0.0235 (8)0.0009 (7)0.0075 (6)0.0030 (7)
C100.0268 (8)0.0232 (9)0.0225 (7)0.0002 (8)0.0087 (6)0.0025 (7)
C200.0230 (8)0.0237 (9)0.0189 (7)0.0018 (7)0.0038 (6)0.0014 (7)
C130.0336 (9)0.0265 (9)0.0245 (8)0.0009 (8)0.0142 (7)0.0014 (7)
C40.0302 (9)0.0416 (11)0.0220 (8)0.0001 (9)0.0077 (7)−0.0028 (8)
C110.0249 (8)0.0234 (9)0.0271 (8)−0.0015 (7)0.0071 (7)0.0002 (7)
C70.0205 (8)0.0217 (8)0.0251 (8)0.0032 (7)0.0072 (6)0.0033 (7)
C50.0248 (8)0.0420 (11)0.0233 (8)0.0040 (8)0.0069 (7)−0.0009 (8)
C80.0219 (8)0.0238 (9)0.0204 (7)0.0026 (7)0.0044 (6)−0.0005 (7)
C190.0203 (8)0.0248 (9)0.0221 (7)0.0041 (7)0.0057 (6)−0.0013 (7)
C30.0283 (9)0.0353 (10)0.0277 (8)−0.0006 (8)0.0122 (7)−0.0057 (8)
C20.0214 (8)0.0294 (9)0.0285 (8)−0.0004 (8)0.0101 (7)−0.0018 (7)

Geometric parameters (Å, °)

O2—C81.3459 (18)C15—C161.392 (2)
O2—C61.4557 (16)C15—C81.499 (2)
O4—C81.2034 (17)C16—C171.388 (2)
O1—C71.3447 (17)C16—H160.9300
O1—C11.4694 (16)C14—C131.380 (2)
O3—C71.2101 (17)C14—H140.9300
O6—N11.2283 (16)C17—H170.9300
O7—N21.2267 (16)C10—C111.385 (2)
O5—N11.2258 (16)C10—H100.9300
O8—N21.2281 (17)C20—C191.384 (2)
C9—C101.387 (2)C20—H200.9300
C9—C141.393 (2)C13—H130.9300
C9—C71.489 (2)C4—C31.518 (2)
N1—C121.4710 (19)C4—C51.526 (2)
N2—C181.4746 (18)C4—H4A0.9700
C18—C171.378 (2)C4—H4B0.9700
C18—C191.377 (2)C11—H110.9300
C1—C61.510 (2)C5—H5A0.9700
C1—C21.5166 (19)C5—H5B0.9700
C1—H10.9800C19—H190.9300
C12—C111.382 (2)C3—C21.529 (2)
C12—C131.381 (2)C3—H3A0.9700
C6—C51.517 (2)C3—H3B0.9700
C6—H60.9800C2—H2A0.9700
C15—C201.385 (2)C2—H2B0.9700
C8—O2—C6117.78 (12)C9—C10—H10119.8
C7—O1—C1116.87 (11)C15—C20—C19120.09 (14)
C10—C9—C14120.30 (13)C15—C20—H20120.0
C10—C9—C7123.02 (13)C19—C20—H20120.0
C14—C9—C7116.65 (13)C14—C13—C12118.21 (14)
O6—N1—O5124.36 (13)C14—C13—H13120.9
O6—N1—C12118.07 (13)C12—C13—H13120.9
O5—N1—C12117.57 (13)C3—C4—C5110.47 (13)
O7—N2—O8124.06 (13)C3—C4—H4A109.6
O7—N2—C18118.23 (14)C5—C4—H4A109.6
O8—N2—C18117.70 (14)C3—C4—H4B109.6
C17—C18—C19123.34 (13)C5—C4—H4B109.6
C17—C18—N2118.64 (14)H4A—C4—H4B108.1
C19—C18—N2118.01 (13)C12—C11—C10117.91 (15)
O1—C1—C6107.69 (12)C12—C11—H11121.0
O1—C1—C2108.28 (11)C10—C11—H11121.0
C6—C1—C2111.39 (12)O3—C7—O1124.61 (14)
O1—C1—H1109.8O3—C7—C9122.21 (14)
C6—C1—H1109.8O1—C7—C9113.17 (13)
C2—C1—H1109.8C6—C5—C4110.17 (12)
C11—C12—C13123.12 (14)C6—C5—H5A109.6
C11—C12—N1118.90 (14)C4—C5—H5A109.6
C13—C12—N1117.97 (13)C6—C5—H5B109.6
O2—C6—C1105.67 (11)C4—C5—H5B109.6
O2—C6—C5110.34 (12)H5A—C5—H5B108.1
C1—C6—C5111.59 (13)O4—C8—O2124.52 (13)
O2—C6—H6109.7O4—C8—C15124.49 (14)
C1—C6—H6109.7O2—C8—C15110.98 (13)
C5—C6—H6109.7C18—C19—C20118.17 (14)
C20—C15—C16120.49 (14)C18—C19—H19120.9
C20—C15—C8117.80 (14)C20—C19—H19120.9
C16—C15—C8121.67 (14)C4—C3—C2110.83 (13)
C17—C16—C15120.01 (14)C4—C3—H3A109.5
C17—C16—H16120.0C2—C3—H3A109.5
C15—C16—H16120.0C4—C3—H3B109.5
C13—C14—C9120.12 (14)C2—C3—H3B109.5
C13—C14—H14119.9H3A—C3—H3B108.1
C9—C14—H14119.9C1—C2—C3110.46 (12)
C18—C17—C16117.87 (14)C1—C2—H2A109.6
C18—C17—H17121.1C3—C2—H2A109.6
C16—C17—H17121.1C1—C2—H2B109.6
C11—C10—C9120.32 (14)C3—C2—H2B109.6
C11—C10—H10119.8H2A—C2—H2B108.1

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C14—H14···O8i0.932.403.240 (2)150
C16—H16···O30.932.573.4374 (19)156
C19—H19···O3ii0.932.293.0919 (19)145
C5—H5A···Cg2iii0.972.793.7273 (18)162

Symmetry codes: (i) −x, −y, −z+1; (ii) −x, y+1/2, −z+1/2; (iii) x, −y−1/2, z−3/2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SI2117).

References

  • Burnett, M. N. & Johnson, C. K. (1996). ORTEPIII Report ORNL-6895. Oak Ridge National Laboratory, Tennessee, USA.
  • Ciunik, Z. & Jarosz, S. (1998). J. Mol. Struct.442, 115–119.
  • Desiraju, G. R. & Steiner, T. (2001). The Weak Hydrogen Bond: In Structural Chemistry and Biology, IUCr Monographs on Crystallography, No. 9, pp. 122–201. New York: Oxford University Press Inc.
  • Farrugia, L. J. (1999). J. Appl. Cryst.32, 837–838.
  • Hayashi, Y., Yamaguchi, J., Sumiya, T., Hibino, K. & Shoji, M. (2004). J. Org. Chem.69, 5966–5973. [PubMed]
  • Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst.39, 453–457.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Siemens (1995). SMART and SAINT Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.
  • Westrip, S. P. (2008). publCIF In preparation.

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography