organic compounds
(–)-(S)-N,N′-Bis[1-(1-naphthyl)ethyl]oxalamide
aDEP Facultad de Ciencias Químicas, UANL, Guerrero y Progreso S/N, Col. Treviño, 64570 Monterrey, NL, Mexico, bLaboratorio de Síntesis de Complejos, Facultad de Ciencias Químicas, Universidad Autónoma de Puebla, AP 1067, 72001 Puebla, Pue., Mexico, and cUniversidad de la Cañada, Cd. Universitaria, 68540, Teotitlán de Flores Magón, Oax., Mexico
*Correspondence e-mail: sylvain_bernes@Hotmail.com
The title molecule, C26H24N2O2, displays C2 symmetry, with the molecule located on a twofold axis perpendicular to the plane of the oxalamide unit –NH—CO—CO—NH–. The oxalamide core deviates from planarity, as reflected by the O=C—C=O and N—C—C—N torsion angles of 164.3 (5) and 163.2 (5)°, respectively. The naphthyl groups are oriented toward the same face of the oxalamide mean plane and make a dihedral angle of 43.76 (8)°. This conformation is suitable for the formation of intermolecular N—H⋯O hydrogen bonds, giving noncentrosymmetric dimers incorporating R22(10) ring motifs. These nonbonding interactions propagate along the 61 screw axis normal to the molecular twofold axis, resulting in a single-stranded right-handed helix parallel to [001]. In the crystal, Δ helices are arranged side-by-side and interact through π–π contacts between naphthyl groups. The shortest centroid–centroid separation between interacting benzene rings is 3.623 (4) Å.
Related literature
For crystal structures of closely related oxalamides, see: Štefanić et al. (2003); Zhang et al. (2006); Lee & Wang (2007); Lee (2010). For general references on dicarboxamides and oxalamides, and their synthesis under solvent-free conditions, see: Bernès et al. (2008); Montero-Vázquez et al. (2008); Jeon et al. (2005); Noyori (2005). For helicity assignment in enantiomorphic space groups, see: Ha & Allewell (1997).
Experimental
Crystal data
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Data collection
|
Refinement
|
Data collection: XSCANS (Siemens, 1996); cell XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536810043424/jh2225sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810043424/jh2225Isup2.hkl
Under solvent-free conditions, a mixture of oxalyl chloride (0.2 g, 1.5 mmol) and (S)-(–)-1-(1-naphthyl)ethylamine (0.53 g, 3.0 mmol) in a 1:2 molar ratio were mixed at room temperature, giving a white solid. The crude was recrystallized twice from CH2Cl2, affording colorless crystals of the title compound. Yield 96%; m.p. 240–242 °C. Spectroscopic data: [α]25D = -10.5 (c 1, CHCl3). FT—IR (KBr): 3450 cm-1 (NH), 1650 cm-1 (CO). 1H NMR (400 MHz, CDCl3/TMS): δ = 1.5–1.7 (d, 6H, CHCH3), 4.1 (br s, 2H, NH), 5.1 (q, 2H, CHCH3), 7.3–8.1 (m, 14 H, Ar); 13C NMR (100 MHz, CDCl3/TMS) δ = 23.3 (CCH3), 46.9 (CHCH3), 122.7 (Ar), 125.1 (Ar), 125.6 (Ar), 127.9 (Ar), 128.9 (Ar), 128.4 (Ar), 133.7 (Ar), 138.9.(Ar), 144.3 (Ar), 158.5 (C=O). MS—EI: m/z = 396 (M+).
All C-bonded H atoms were placed in idealized positions and refined as riding to their carrier C atoms, with bond lengths fixed to 0.93 (aromatic CH), 0.96 (methyl CH3), and 0.98 Å (methine CH). Atom H2 bonded to N2 was found in a difference map and refined freely, although N—H bond length was restrained to 0.91 (1) Å. Isotropic displacement parameters were calculated as Uiso(H) = 1.5Ueq(carrier atom) for the methyl group and Uiso(H) = 1.2Ueq(carrier atom) otherwise. The
was assigned from the known configuration of the chiral amine used as starting material, and measured Friedel pairs (705) were merged.Earlier, we have focused our attention on dicarboxamides (Bernès et al., 2008), mostly due to their versatile and interesting properties. In continuation of this work, we synthesized the title chiral compound, under the solvent-free approach, because the reactions occur under mild conditions and usually require easier workup procedures and simpler equipment. Likewise, reducing the use of organic solvents and minimizing the formation of waste are worth-considering points to keep in mind by using this protocol (Jeon et al., 2005; Noyori, 2005).
The title molecule belongs to the oxalamide family, a well studied class of compounds, which are useful in many areas (e.g. Montero-Vázquez et al., 2008). The molecule is placed on a twofold axis, passing by the midpoint of the central C1—C1i bond (symmetry code i: x-y, -y, 1 - z). The twofold axis is perpendicular to the mean plane of the core oxalamide group. In contrast to other oxalamide derivatives (e.g. Zhang et al., 2006) the oxalamide group in the title compound is not planar. As a consequence, trans angles O1—C1—C1i—O1i and N2—C1—C1i—N2i deviate significantly from 180°. N atoms are substituted by chiral groups including naphthyl cycles, which make a dihedral angle of 43.76 (8)° (Fig. 1).
The C2-symmetric molecules are connected in the crystal through N2—H2···O1ii hydrogen bonds (symmetry code ii: y, -x + y, z - 1/6), which generate R22(10) ring motifs (Fig. 2). Such motifs have been observed in related chiral (Štefanić et al., 2003) and achiral (Lee & Wang, 2007) oxalamides, but gave different supramolecular structures, depending of the ability of terminal groups to be involved in hydrogen bonds. In the case of the title oxalamide, hydrogen bonds form a supramolecular structure based on a single stranded helix using the screw axis 61 as backbone (Fig. 2, inset). The molecular and supramolecular axes are thus perpendicular. Although the
is enantiomorphic, the helicity of the supramolecular structure can be assigned, since the of the is known (Ha & Allewell, 1997). The S configuration of chiral center C3 affords right-handed helix oriented along [001]. It is worth noting that such chiral supramolecular structures cannot be achieved for centrosymmetric oxalamide derivatives (Zhang et al., 2006; Lee, 2010).The π–π contacts involving terminal naphthyl groups. The shortest intermolecular separation between symmetry-related benzene rings is 3.623 (4) Å [Cg···Cgiii, where Cg is the centroid of ring C9···C14 and iii is symmetry code: 1 - y, 1 - x, 5/6 - z]. This contact should however be regarded as a secondary interaction compared to hydrogen bonds forming the one-dimensional supramolecular structure. Although the ring approach is short, constraints induced by reduce the efficiency of such contacts. For instance, π systems involved in π–π contacts are not parallel, making a dihedral angle of 11.7 (2)°.
of the title compound is build up on densely packed parallel Δ helix, which interact throughFor crystal structures of closely related oxalamides, see: Štefanić et al. (2003); Zhang et al. (2006); Lee & Wang (2007); Lee (2010). For general references on dicarboxamides and oxalamides, and their synthesis under solvent-free conditions, see: Bernès et al. (2008); Montero-Vázquez et al. (2008); Jeon et al. (2005); Noyori (2005). For helicity assignment in enantiomorphic space groups, see: Ha & Allewell (1997).
Data collection: XSCANS (Siemens, 1996); cell
XSCANS (Siemens, 1996); data reduction: XSCANS (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).C26H24N2O2 | Dx = 1.227 Mg m−3 |
Mr = 396.47 | Melting point: 513 K |
Hexagonal, P6122 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 61 2 (0 0 -1) | Cell parameters from 67 reflections |
a = 11.4489 (11) Å | θ = 4.1–11.9° |
c = 28.350 (4) Å | µ = 0.08 mm−1 |
V = 3218.2 (7) Å3 | T = 298 K |
Z = 6 | Prism, colourless |
F(000) = 1260 | 0.40 × 0.22 × 0.20 mm |
Siemens P4 diffractometer | Rint = 0.057 |
Radiation source: fine-focus sealed tube | θmax = 25.1°, θmin = 2.1° |
Graphite monochromator | h = −13→2 |
ω scans | k = −1→13 |
5314 measured reflections | l = −33→1 |
1208 independent reflections | 3 standard reflections every 97 reflections |
730 reflections with I > 2σ(I) | intensity decay: 1% |
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)] = 0.043 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.138 | w = 1/[σ2(Fo2) + (0.0649P)2 + 0.2213P] where P = (Fo2 + 2Fc2)/3 |
S = 1.11 | (Δ/σ)max < 0.001 |
1208 reflections | Δρmax = 0.12 e Å−3 |
141 parameters | Δρmin = −0.14 e Å−3 |
1 restraint | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 constraints | Extinction coefficient: 0.011 (2) |
Primary atom site location: structure-invariant direct methods |
C26H24N2O2 | Z = 6 |
Mr = 396.47 | Mo Kα radiation |
Hexagonal, P6122 | µ = 0.08 mm−1 |
a = 11.4489 (11) Å | T = 298 K |
c = 28.350 (4) Å | 0.40 × 0.22 × 0.20 mm |
V = 3218.2 (7) Å3 |
Siemens P4 diffractometer | Rint = 0.057 |
5314 measured reflections | 3 standard reflections every 97 reflections |
1208 independent reflections | intensity decay: 1% |
730 reflections with I > 2σ(I) |
R[F2 > 2σ(F2)] = 0.043 | 1 restraint |
wR(F2) = 0.138 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.11 | Δρmax = 0.12 e Å−3 |
1208 reflections | Δρmin = −0.14 e Å−3 |
141 parameters |
x | y | z | Uiso*/Ueq | ||
O1 | 0.1760 (3) | 0.1496 (2) | 0.53227 (7) | 0.0718 (8) | |
C1 | 0.1517 (3) | 0.0760 (3) | 0.49767 (11) | 0.0539 (8) | |
N2 | 0.1898 (3) | 0.1213 (3) | 0.45411 (9) | 0.0594 (8) | |
H2 | 0.168 (3) | 0.058 (3) | 0.4311 (9) | 0.071* | |
C3 | 0.2678 (3) | 0.2653 (3) | 0.44315 (11) | 0.0589 (9) | |
H3A | 0.3249 | 0.3110 | 0.4705 | 0.071* | |
C4 | 0.3604 (4) | 0.2880 (4) | 0.40144 (13) | 0.0852 (13) | |
H4B | 0.4194 | 0.2535 | 0.4088 | 0.128* | |
H4C | 0.4131 | 0.3828 | 0.3949 | 0.128* | |
H4D | 0.3072 | 0.2420 | 0.3743 | 0.128* | |
C5 | 0.1787 (4) | 0.3254 (4) | 0.43491 (11) | 0.0632 (10) | |
C6 | 0.0662 (4) | 0.2582 (5) | 0.40749 (15) | 0.0878 (12) | |
H6A | 0.0436 | 0.1736 | 0.3957 | 0.105* | |
C7 | −0.0158 (6) | 0.3123 (7) | 0.39661 (18) | 0.1117 (17) | |
H7A | −0.0907 | 0.2651 | 0.3773 | 0.134* | |
C8 | 0.0142 (6) | 0.4343 (7) | 0.4144 (2) | 0.1100 (17) | |
H8B | −0.0420 | 0.4692 | 0.4079 | 0.132* | |
C9 | 0.1289 (6) | 0.5082 (5) | 0.44246 (16) | 0.0855 (13) | |
C10 | 0.1624 (8) | 0.6363 (6) | 0.4601 (2) | 0.119 (2) | |
H10B | 0.1074 | 0.6721 | 0.4529 | 0.143* | |
C11 | 0.2721 (8) | 0.7080 (6) | 0.4873 (2) | 0.126 (2) | |
H11D | 0.2911 | 0.7913 | 0.4993 | 0.151* | |
C12 | 0.3575 (6) | 0.6564 (5) | 0.49739 (19) | 0.1110 (17) | |
H12B | 0.4343 | 0.7068 | 0.5156 | 0.133* | |
C13 | 0.3293 (5) | 0.5332 (4) | 0.48084 (13) | 0.0781 (12) | |
H13B | 0.3868 | 0.5003 | 0.4881 | 0.094* | |
C14 | 0.2145 (4) | 0.4552 (4) | 0.45291 (12) | 0.0660 (10) |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0854 (19) | 0.0634 (16) | 0.0510 (13) | 0.0256 (14) | 0.0089 (12) | −0.0117 (12) |
C1 | 0.055 (2) | 0.0567 (19) | 0.0495 (17) | 0.0279 (17) | 0.0013 (16) | −0.0044 (19) |
N2 | 0.071 (2) | 0.0555 (19) | 0.0477 (15) | 0.0284 (16) | 0.0035 (15) | −0.0042 (13) |
C3 | 0.063 (2) | 0.056 (2) | 0.0540 (18) | 0.0272 (19) | 0.0031 (17) | −0.0023 (16) |
C4 | 0.088 (3) | 0.084 (3) | 0.081 (2) | 0.041 (3) | 0.032 (2) | 0.011 (2) |
C5 | 0.068 (3) | 0.068 (3) | 0.0532 (18) | 0.033 (2) | 0.0073 (19) | 0.0067 (19) |
C6 | 0.087 (3) | 0.093 (3) | 0.087 (3) | 0.048 (3) | −0.015 (3) | −0.001 (3) |
C7 | 0.097 (4) | 0.136 (5) | 0.113 (4) | 0.067 (4) | −0.017 (3) | 0.014 (4) |
C8 | 0.108 (4) | 0.136 (5) | 0.120 (4) | 0.087 (4) | 0.018 (4) | 0.035 (4) |
C9 | 0.104 (4) | 0.087 (3) | 0.081 (3) | 0.060 (3) | 0.034 (3) | 0.026 (3) |
C10 | 0.175 (7) | 0.104 (4) | 0.116 (4) | 0.098 (5) | 0.066 (4) | 0.037 (4) |
C11 | 0.178 (7) | 0.073 (4) | 0.128 (5) | 0.065 (4) | 0.061 (5) | 0.013 (3) |
C12 | 0.129 (5) | 0.065 (3) | 0.110 (3) | 0.027 (3) | 0.030 (4) | −0.003 (3) |
C13 | 0.089 (3) | 0.058 (3) | 0.075 (2) | 0.028 (2) | 0.015 (2) | −0.002 (2) |
C14 | 0.078 (3) | 0.063 (2) | 0.0587 (19) | 0.036 (2) | 0.025 (2) | 0.014 (2) |
O1—C1 | 1.231 (4) | C7—C8 | 1.358 (7) |
C1—N2 | 1.326 (4) | C7—H7A | 0.9300 |
C1—C1i | 1.512 (7) | C8—C9 | 1.400 (7) |
N2—C3 | 1.463 (4) | C8—H8B | 0.9300 |
N2—H2 | 0.911 (10) | C9—C10 | 1.409 (7) |
C3—C5 | 1.506 (5) | C9—C14 | 1.418 (6) |
C3—C4 | 1.522 (5) | C10—C11 | 1.348 (8) |
C3—H3A | 0.9800 | C10—H10B | 0.9300 |
C4—H4B | 0.9600 | C11—C12 | 1.401 (7) |
C4—H4C | 0.9600 | C11—H11D | 0.9300 |
C4—H4D | 0.9600 | C12—C13 | 1.363 (6) |
C5—C6 | 1.366 (5) | C12—H12B | 0.9300 |
C5—C14 | 1.424 (5) | C13—C14 | 1.406 (6) |
C6—C7 | 1.394 (6) | C13—H13B | 0.9300 |
C6—H6A | 0.9300 | ||
O1—C1—N2 | 123.8 (3) | C8—C7—C6 | 119.6 (5) |
O1—C1—C1i | 121.4 (4) | C8—C7—H7A | 120.2 |
N2—C1—C1i | 114.8 (3) | C6—C7—H7A | 120.2 |
C1—N2—C3 | 122.3 (3) | C7—C8—C9 | 120.8 (5) |
C1—N2—H2 | 117 (2) | C7—C8—H8B | 119.6 |
C3—N2—H2 | 121 (2) | C9—C8—H8B | 119.6 |
N2—C3—C5 | 112.1 (3) | C8—C9—C10 | 121.0 (6) |
N2—C3—C4 | 109.8 (3) | C8—C9—C14 | 120.0 (4) |
C5—C3—C4 | 112.0 (3) | C10—C9—C14 | 119.0 (5) |
N2—C3—H3A | 107.6 | C11—C10—C9 | 121.5 (6) |
C5—C3—H3A | 107.6 | C11—C10—H10B | 119.2 |
C4—C3—H3A | 107.6 | C9—C10—H10B | 119.2 |
C3—C4—H4B | 109.5 | C10—C11—C12 | 119.6 (6) |
C3—C4—H4C | 109.5 | C10—C11—H11D | 120.2 |
H4B—C4—H4C | 109.5 | C12—C11—H11D | 120.2 |
C3—C4—H4D | 109.5 | C13—C12—C11 | 120.8 (6) |
H4B—C4—H4D | 109.5 | C13—C12—H12B | 119.6 |
H4C—C4—H4D | 109.5 | C11—C12—H12B | 119.6 |
C6—C5—C14 | 119.4 (4) | C12—C13—C14 | 120.9 (5) |
C6—C5—C3 | 119.6 (3) | C12—C13—H13B | 119.6 |
C14—C5—C3 | 120.9 (3) | C14—C13—H13B | 119.6 |
C5—C6—C7 | 122.0 (5) | C13—C14—C9 | 118.2 (4) |
C5—C6—H6A | 119.0 | C13—C14—C5 | 123.7 (4) |
C7—C6—H6A | 119.0 | C9—C14—C5 | 118.1 (4) |
O1—C1—N2—C3 | 1.3 (5) | C8—C9—C10—C11 | 179.7 (5) |
O1—C1—C1i—O1i | 164.3 (5) | C14—C9—C10—C11 | −1.2 (7) |
C1i—C1—N2—C3 | −178.1 (2) | C9—C10—C11—C12 | 1.7 (8) |
C1—N2—C3—C5 | −86.9 (4) | C10—C11—C12—C13 | −1.4 (8) |
C1—N2—C3—C4 | 148.0 (3) | C11—C12—C13—C14 | 0.5 (7) |
N2—C3—C5—C6 | −44.7 (4) | C12—C13—C14—C9 | 0.0 (5) |
N2—C1—C1i—N2i | 163.2 (5) | C12—C13—C14—C5 | −179.4 (4) |
C4—C3—C5—C6 | 79.2 (4) | C8—C9—C14—C13 | 179.4 (4) |
N2—C3—C5—C14 | 139.2 (3) | C10—C9—C14—C13 | 0.3 (5) |
C4—C3—C5—C14 | −96.9 (4) | C8—C9—C14—C5 | −1.2 (5) |
C14—C5—C6—C7 | −0.3 (6) | C10—C9—C14—C5 | 179.8 (4) |
C3—C5—C6—C7 | −176.5 (4) | C6—C5—C14—C13 | −179.0 (3) |
C5—C6—C7—C8 | −1.5 (8) | C3—C5—C14—C13 | −2.9 (5) |
C6—C7—C8—C9 | 1.9 (8) | C6—C5—C14—C9 | 1.6 (5) |
C7—C8—C9—C10 | 178.5 (5) | C3—C5—C14—C9 | 177.7 (3) |
C7—C8—C9—C14 | −0.6 (7) |
Symmetry code: (i) x−y, −y, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O1ii | 0.91 (1) | 2.06 (2) | 2.931 (3) | 161 (3) |
Symmetry code: (ii) y, −x+y, z−1/6. |
Experimental details
Crystal data | |
Chemical formula | C26H24N2O2 |
Mr | 396.47 |
Crystal system, space group | Hexagonal, P6122 |
Temperature (K) | 298 |
a, c (Å) | 11.4489 (11), 28.350 (4) |
V (Å3) | 3218.2 (7) |
Z | 6 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.40 × 0.22 × 0.20 |
Data collection | |
Diffractometer | Siemens P4 |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5314, 1208, 730 |
Rint | 0.057 |
(sin θ/λ)max (Å−1) | 0.596 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.043, 0.138, 1.11 |
No. of reflections | 1208 |
No. of parameters | 141 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.12, −0.14 |
Computer programs: XSCANS (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), Mercury (Macrae et al., 2006).
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O1i | 0.911 (10) | 2.055 (15) | 2.931 (3) | 161 (3) |
Symmetry code: (i) y, −x+y, z−1/6. |
Acknowledgements
Support from VIEP-UAP (grant No. GUPJ-NAT10-G) is acknowledged.
References
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This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Earlier, we have focused our attention on dicarboxamides (Bernès et al., 2008), mostly due to their versatile and interesting properties. In continuation of this work, we synthesized the title chiral compound, under the solvent-free approach, because the reactions occur under mild conditions and usually require easier workup procedures and simpler equipment. Likewise, reducing the use of organic solvents and minimizing the formation of waste are worth-considering points to keep in mind by using this protocol (Jeon et al., 2005; Noyori, 2005).
The title molecule belongs to the oxalamide family, a well studied class of compounds, which are useful in many areas (e.g. Montero-Vázquez et al., 2008). The molecule is placed on a twofold axis, passing by the midpoint of the central C1—C1i bond (symmetry code i: x-y, -y, 1 - z). The twofold axis is perpendicular to the mean plane of the core oxalamide group. In contrast to other oxalamide derivatives (e.g. Zhang et al., 2006) the oxalamide group in the title compound is not planar. As a consequence, trans angles O1—C1—C1i—O1i and N2—C1—C1i—N2i deviate significantly from 180°. N atoms are substituted by chiral groups including naphthyl cycles, which make a dihedral angle of 43.76 (8)° (Fig. 1).
The C2-symmetric molecules are connected in the crystal through N2—H2···O1ii hydrogen bonds (symmetry code ii: y, -x + y, z - 1/6), which generate R22(10) ring motifs (Fig. 2). Such motifs have been observed in related chiral (Štefanić et al., 2003) and achiral (Lee & Wang, 2007) oxalamides, but gave different supramolecular structures, depending of the ability of terminal groups to be involved in hydrogen bonds. In the case of the title oxalamide, hydrogen bonds form a supramolecular structure based on a single stranded helix using the screw axis 61 as backbone (Fig. 2, inset). The molecular and supramolecular axes are thus perpendicular. Although the space group is enantiomorphic, the helicity of the supramolecular structure can be assigned, since the chirality of the asymmetric unit is known (Ha & Allewell, 1997). The S configuration of chiral center C3 affords right-handed helix oriented along [001]. It is worth noting that such chiral supramolecular structures cannot be achieved for centrosymmetric oxalamide derivatives (Zhang et al., 2006; Lee, 2010).
The crystal structure of the title compound is build up on densely packed parallel Δ helix, which interact through π–π contacts involving terminal naphthyl groups. The shortest intermolecular separation between symmetry-related benzene rings is 3.623 (4) Å [Cg···Cgiii, where Cg is the centroid of ring C9···C14 and iii is symmetry code: 1 - y, 1 - x, 5/6 - z]. This contact should however be regarded as a secondary interaction compared to hydrogen bonds forming the one-dimensional supramolecular structure. Although the ring approach is short, constraints induced by molecular conformation reduce the efficiency of such contacts. For instance, π systems involved in π–π contacts are not parallel, making a dihedral angle of 11.7 (2)°.