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The title compound, C42H46N2O6, crystallizes with half a mol­ecule in the asymmetric unit, the molecule being centrosymmetric. The ethyl ester and N-formyl side chains attached to the Cα atom of the mol­ecule adopt a trans and cis configuration, respectively. The crystal structure is stabilized by C—H...O, N—H...O and C—H...π interactions and herring-bone-type packing is observed.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802015313/bt6180sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536802015313/bt6180Isup2.hkl
Contains datablock I

CCDC reference: 197486

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.004 Å
  • R factor = 0.067
  • wR factor = 0.179
  • Data-to-parameter ratio = 20.1

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

General Notes

ABSTY_01 Extra text has been found in the _exptl_absorpt_correction_type field, which should be only a single keyword. A literature citation should be included in the _exptl_absorpt_process_details field.

Comment top

Macrocyclic molecules act as synthetic receptors in molecular recognition (Keehn & Rosenfeld, 1983). Incorporation of unusual amino acid Aib (α-aminoisobutyric acid) with a paracyclophane unit resulted in the title compound, (I) (Kotha et al., 2002). This synthesis yielded both the cis and the trans isomer. The crystal structure of the trans isomer, (I), is reported here. The compound crystallized from a mixture of HCl and petroleum ether in space group Pbca, with one half molecule in the asymmetric unit.

An ORTEP-3 diagram (Farrugia, 1997) of (I) is shown in Fig. 1. The conformation of the ethyl acetate side chain is trans [C1—C19—O20—C20 = 176.4 (2)°], while that of the N-formyl side chain is cis [C1—N1—C18—O18 = 1.0 (4)°] with respect to the Cα atom.

One half of the molecule is linked to the other half through an N—H···O hydrogen bond. Herring-bone-type of packing is stabilized by van der Waals forces, and C—H···O and C—H···π-type intermolecular interactions (Figs. 2 and 3).

Experimental top

The title unusual macrocyclic cyclophane-based α-amino acid derivative has been synthesized by coupling of ethyl isocyanoacetate with 1,2-bis(4-bromomethylphenyl)ethane under phase-tranfer-catalysis conditions.

Refinement top

The H atoms were fixed geometrically at calculated positions.

Computing details top

Data collection: SMART (Bruker, 1999); cell refinement: SMART; data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title molecule with 50% probability displacement ellipsoids and the atomic numbering scheme.
[Figure 2] Fig. 2. Stereoview of the herring-bone-type packing of the molecules in the ac plane.
[Figure 3] Fig. 3. Stereoview of the molecule of (I), showing the N—H···O, C—H···O and C—H···π interactions. For clarity, only H atoms involved in hydrogen bonding are shown.
Macrocyclic cyclophane-based unusual amino acid top
Crystal data top
C42H46N2O6Dx = 1.182 Mg m3
Mr = 674.81Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, PbcaCell parameters from 4538 reflections
a = 15.890 (2) Åθ = 1.9–28.0°
b = 11.2944 (16) ŵ = 0.08 mm1
c = 21.125 (3) ÅT = 293 K
V = 3791.1 (9) Å3Rectangular, colourless
Z = 40.54 × 0.45 × 0.45 mm
F(000) = 1440
Data collection top
CCD area detector
diffractometer
3019 reflections with I > 2σ(I)
Radiation source: sealed tubeRint = 0.032
Graphite monochromatorθmax = 28.0°, θmin = 1.9°
ϕ and ω scansh = 2020
31175 measured reflectionsk = 1214
4538 independent reflectionsl = 2727
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)] = 0.067Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.179H-atom parameters constrained
S = 1.09 w = 1/[σ2(Fo2) + (0.0764P)2 + 0.779P]
where P = (Fo2 + 2Fc2)/3
4538 reflections(Δ/σ)max < 0.001
226 parametersΔρmax = 0.19 e Å3
0 restraintsΔρmin = 0.14 e Å3
Crystal data top
C42H46N2O6V = 3791.1 (9) Å3
Mr = 674.81Z = 4
Orthorhombic, PbcaMo Kα radiation
a = 15.890 (2) ŵ = 0.08 mm1
b = 11.2944 (16) ÅT = 293 K
c = 21.125 (3) Å0.54 × 0.45 × 0.45 mm
Data collection top
CCD area detector
diffractometer
3019 reflections with I > 2σ(I)
31175 measured reflectionsRint = 0.032
4538 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0670 restraints
wR(F2) = 0.179H-atom parameters constrained
S = 1.09Δρmax = 0.19 e Å3
4538 reflectionsΔρmin = 0.14 e Å3
226 parameters
Special details top

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
N10.12073 (9)0.05376 (13)0.45160 (7)0.0529 (4)
H10.07700.01700.46540.063*
C10.11952 (11)0.18242 (16)0.45533 (9)0.0516 (5)
C20.12312 (13)0.23942 (19)0.38852 (11)0.0654 (6)
H2A0.12390.32490.39310.078*
H2B0.17520.21600.36810.078*
C30.05030 (14)0.2053 (2)0.34661 (10)0.0641 (6)
C40.02391 (17)0.2704 (2)0.34598 (13)0.0832 (7)
H40.02660.34030.36910.100*
C50.09327 (18)0.2349 (3)0.31245 (13)0.0890 (8)
H50.14180.28080.31390.107*
C60.09281 (16)0.1339 (3)0.27705 (10)0.0769 (7)
C70.01896 (17)0.0703 (3)0.27505 (11)0.0830 (7)
H70.01620.00210.25040.100*
C80.05177 (16)0.1060 (2)0.30918 (11)0.0761 (7)
H80.10090.06150.30650.091*
C90.17199 (19)0.0926 (3)0.75679 (11)0.0957 (9)
H9A0.16760.11460.80110.115*
H9B0.21970.13490.73920.115*
C100.18968 (19)0.0372 (3)0.75309 (12)0.0963 (9)
H10A0.24350.05270.77320.116*
H10B0.14690.07910.77700.116*
C110.19194 (14)0.0873 (2)0.68636 (10)0.0734 (6)
C120.15145 (15)0.1912 (3)0.67162 (12)0.0813 (7)
H120.12230.23130.70320.098*
C130.15277 (14)0.2374 (2)0.61178 (12)0.0725 (6)
H130.12470.30800.60380.087*
C140.19491 (12)0.18159 (18)0.56274 (10)0.0589 (5)
C150.23656 (14)0.0784 (2)0.57747 (11)0.0706 (6)
H150.26620.03870.54590.085*
C160.23534 (15)0.0322 (2)0.63824 (12)0.0776 (7)
H160.26440.03750.64670.093*
C170.19260 (12)0.23013 (18)0.49639 (11)0.0624 (5)
H17A0.24540.21130.47560.075*
H17B0.18820.31570.49860.075*
C180.18303 (14)0.01222 (19)0.42894 (11)0.0675 (6)
H180.17440.09370.42900.081*
O180.24981 (10)0.02203 (16)0.40823 (9)0.0904 (6)
C190.03523 (11)0.21237 (16)0.48647 (9)0.0516 (5)
O190.01518 (8)0.14112 (12)0.50321 (8)0.0683 (4)
C200.05690 (14)0.3668 (2)0.51835 (15)0.0853 (8)
H20A0.07130.44370.50100.102*
H20B0.10020.31110.50560.102*
O200.02433 (8)0.32867 (11)0.49254 (7)0.0657 (4)
C210.0549 (2)0.3744 (4)0.58686 (18)0.1363 (14)
H21A0.10910.39880.60210.204*
H21B0.01320.43100.59960.204*
H21C0.04120.29820.60420.204*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0480 (8)0.0443 (9)0.0664 (10)0.0049 (7)0.0140 (7)0.0037 (7)
C10.0457 (10)0.0420 (10)0.0672 (12)0.0068 (8)0.0099 (8)0.0066 (9)
C20.0643 (12)0.0567 (13)0.0751 (14)0.0096 (10)0.0170 (11)0.0160 (10)
C30.0685 (13)0.0634 (13)0.0604 (12)0.0023 (10)0.0136 (10)0.0150 (10)
C40.0945 (18)0.0730 (16)0.0820 (17)0.0164 (14)0.0069 (14)0.0015 (13)
C50.0901 (18)0.102 (2)0.0754 (16)0.0285 (16)0.0115 (14)0.0010 (15)
C60.0813 (16)0.1013 (19)0.0482 (11)0.0132 (14)0.0040 (11)0.0086 (12)
C70.0973 (18)0.0972 (19)0.0544 (13)0.0090 (15)0.0079 (12)0.0122 (12)
C80.0757 (15)0.0891 (17)0.0637 (13)0.0122 (13)0.0181 (12)0.0037 (12)
C90.1006 (19)0.137 (3)0.0494 (12)0.0148 (19)0.0134 (12)0.0044 (14)
C100.0968 (19)0.133 (3)0.0594 (14)0.0046 (18)0.0194 (13)0.0209 (15)
C110.0649 (13)0.0928 (18)0.0626 (13)0.0033 (12)0.0107 (10)0.0226 (12)
C120.0713 (15)0.0980 (19)0.0747 (16)0.0082 (13)0.0072 (12)0.0398 (14)
C130.0632 (13)0.0693 (14)0.0849 (16)0.0085 (11)0.0135 (12)0.0240 (12)
C140.0431 (10)0.0562 (12)0.0773 (13)0.0076 (9)0.0002 (9)0.0105 (10)
C150.0659 (13)0.0737 (15)0.0720 (14)0.0109 (11)0.0089 (11)0.0079 (12)
C160.0784 (15)0.0788 (16)0.0755 (15)0.0150 (12)0.0034 (12)0.0073 (13)
C170.0446 (10)0.0520 (12)0.0905 (15)0.0081 (8)0.0092 (10)0.0025 (10)
C180.0692 (13)0.0550 (12)0.0784 (14)0.0039 (10)0.0206 (11)0.0017 (10)
O180.0726 (10)0.0844 (12)0.1142 (14)0.0054 (8)0.0447 (10)0.0027 (10)
C190.0458 (10)0.0431 (10)0.0659 (12)0.0054 (8)0.0047 (8)0.0036 (9)
O190.0508 (8)0.0488 (8)0.1054 (11)0.0083 (6)0.0252 (7)0.0064 (7)
C200.0564 (13)0.0576 (13)0.142 (3)0.0055 (11)0.0167 (14)0.0015 (14)
O200.0504 (8)0.0432 (8)0.1035 (11)0.0021 (6)0.0131 (7)0.0011 (7)
C210.108 (2)0.173 (4)0.128 (3)0.045 (2)0.041 (2)0.016 (3)
Geometric parameters (Å, º) top
N1—C181.328 (2)C10—H10B0.9700
N1—C11.455 (2)C11—C161.377 (3)
N1—H10.8600C11—C121.374 (4)
C1—C191.530 (3)C12—C131.367 (4)
C1—C171.546 (3)C12—H120.9300
C1—C21.552 (3)C13—C141.385 (3)
C2—C31.507 (3)C13—H130.9300
C2—H2A0.9700C14—C151.376 (3)
C2—H2B0.9700C14—C171.505 (3)
C3—C81.372 (3)C15—C161.386 (3)
C3—C41.390 (3)C15—H150.9300
C4—C51.370 (4)C16—H160.9300
C4—H40.9300C17—H17A0.9700
C5—C61.364 (4)C17—H17B0.9700
C5—H50.9300C18—O181.211 (2)
C6—C71.377 (3)C18—H180.9300
C6—C9i1.520 (4)C19—O191.189 (2)
C7—C81.395 (3)C19—O201.331 (2)
C7—H70.9300C20—C211.450 (4)
C8—H80.9300C20—O201.466 (3)
C9—C101.496 (4)C20—H20A0.9700
C9—C6i1.520 (4)C20—H20B0.9700
C9—H9A0.9700C21—H21A0.9600
C9—H9B0.9700C21—H21B0.9600
C10—C111.519 (4)C21—H21C0.9600
C10—H10A0.9700
C18—N1—C1126.12 (16)H10A—C10—H10B107.6
C18—N1—H1116.9C16—C11—C12117.0 (2)
C1—N1—H1116.9C16—C11—C10121.9 (2)
N1—C1—C19104.81 (14)C12—C11—C10121.1 (2)
N1—C1—C17111.62 (16)C13—C12—C11121.9 (2)
C19—C1—C17109.83 (16)C13—C12—H12119.1
N1—C1—C2111.36 (16)C11—C12—H12119.1
C19—C1—C2109.35 (16)C12—C13—C14121.7 (2)
C17—C1—C2109.74 (15)C12—C13—H13119.2
C3—C2—C1113.55 (15)C14—C13—H13119.2
C3—C2—H2A108.9C15—C14—C13116.7 (2)
C1—C2—H2A108.9C15—C14—C17122.04 (19)
C3—C2—H2B108.9C13—C14—C17121.3 (2)
C1—C2—H2B108.9C14—C15—C16121.4 (2)
H2A—C2—H2B107.7C14—C15—H15119.3
C8—C3—C4116.2 (2)C16—C15—H15119.3
C8—C3—C2122.3 (2)C11—C16—C15121.4 (2)
C4—C3—C2121.4 (2)C11—C16—H16119.3
C5—C4—C3122.2 (2)C15—C16—H16119.3
C5—C4—H4118.9C14—C17—C1114.43 (15)
C3—C4—H4118.9C14—C17—H17A108.7
C6—C5—C4121.6 (2)C1—C17—H17A108.7
C6—C5—H5119.2C14—C17—H17B108.7
C4—C5—H5119.2C1—C17—H17B108.7
C5—C6—C7117.2 (2)H17A—C17—H17B107.6
C5—C6—C9i120.7 (2)O18—C18—N1127.2 (2)
C7—C6—C9i122.1 (3)O18—C18—H18116.4
C6—C7—C8121.4 (2)N1—C18—H18116.4
C6—C7—H7119.3O19—C19—O20123.46 (17)
C8—C7—H7119.3O19—C19—C1124.60 (17)
C3—C8—C7121.3 (2)O20—C19—C1111.93 (15)
C3—C8—H8119.3C21—C20—O20111.7 (2)
C7—C8—H8119.3C21—C20—H20A109.3
C10—C9—C6i115.6 (2)O20—C20—H20A109.3
C10—C9—H9A108.4C21—C20—H20B109.3
C6i—C9—H9A108.4O20—C20—H20B109.3
C10—C9—H9B108.4H20A—C20—H20B107.9
C6i—C9—H9B108.4C19—O20—C20116.14 (15)
H9A—C9—H9B107.4C20—C21—H21A109.5
C9—C10—C11114.7 (2)C20—C21—H21B109.5
C9—C10—H10A108.6H21A—C21—H21B109.5
C11—C10—H10A108.6C20—C21—H21C109.5
C9—C10—H10B108.6H21A—C21—H21C109.5
C11—C10—H10B108.6H21B—C21—H21C109.5
C18—N1—C1—C19178.50 (19)C11—C12—C13—C140.1 (4)
C18—N1—C1—C1759.7 (3)C12—C13—C14—C151.0 (3)
C18—N1—C1—C263.4 (2)C12—C13—C14—C17177.1 (2)
N1—C1—C2—C360.3 (2)C13—C14—C15—C160.8 (3)
C19—C1—C2—C355.1 (2)C17—C14—C15—C16177.4 (2)
C17—C1—C2—C3175.59 (17)C12—C11—C16—C151.3 (4)
C1—C2—C3—C887.9 (2)C10—C11—C16—C15179.7 (2)
C1—C2—C3—C489.2 (2)C14—C15—C16—C110.4 (4)
C8—C3—C4—C53.1 (4)C15—C14—C17—C188.0 (2)
C2—C3—C4—C5174.2 (2)C13—C14—C17—C190.0 (2)
C3—C4—C5—C60.8 (4)N1—C1—C17—C1456.6 (2)
C4—C5—C6—C71.6 (4)C19—C1—C17—C1459.2 (2)
C4—C5—C6—C9i176.5 (3)C2—C1—C17—C14179.43 (17)
C5—C6—C7—C81.7 (4)C1—N1—C18—O181.0 (4)
C9i—C6—C7—C8176.4 (2)N1—C1—C19—O190.5 (3)
C4—C3—C8—C72.9 (3)C17—C1—C19—O19119.6 (2)
C2—C3—C8—C7174.3 (2)C2—C1—C19—O19119.9 (2)
C6—C7—C8—C30.7 (4)N1—C1—C19—O20179.26 (16)
C6i—C9—C10—C1153.9 (3)C17—C1—C19—O2060.7 (2)
C9—C10—C11—C1646.4 (4)C2—C1—C19—O2059.8 (2)
C9—C10—C11—C12134.5 (3)O19—C19—O20—C203.3 (3)
C16—C11—C12—C131.0 (4)C1—C19—O20—C20176.39 (19)
C10—C11—C12—C13179.9 (2)C21—C20—O20—C1989.2 (3)
Symmetry code: (i) x, y, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O19i0.862.142.9272 (19)151
C21—H21A···O18ii0.962.423.317 (4)155
C5—H5···Cg2iii0.933.073.921 (1)153
Symmetry codes: (i) x, y, z+1; (ii) x1/2, y+1/2, z+1; (iii) x+2, y, z.

Experimental details

Crystal data
Chemical formulaC42H46N2O6
Mr674.81
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)293
a, b, c (Å)15.890 (2), 11.2944 (16), 21.125 (3)
V3)3791.1 (9)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.54 × 0.45 × 0.45
Data collection
DiffractometerCCD area detector
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
31175, 4538, 3019
Rint0.032
(sin θ/λ)max1)0.661
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.067, 0.179, 1.09
No. of reflections4538
No. of parameters226
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.19, 0.14

Computer programs: SMART (Bruker, 1999), SMART, SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O19i0.862.142.9272 (19)151
C21—H21A···O18ii0.962.423.317 (4)155
C5—H5···Cg2iii0.933.073.921 (1)153
Symmetry codes: (i) x, y, z+1; (ii) x1/2, y+1/2, z+1; (iii) x+2, y, z.
 

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