N,N′-Bis(4-amino­benz­yl)oxalamide

Juan Saulo Gonzalez-Gonzalez; Francisco J Martínez-Martínez; Efrén V García-Báez; Olivia M Franco-Hernández; Itzia I Padilla-Martínez

doi:10.1107/S1600536811000882

. 2011 Jan 15;67(Pt 2):o398. doi: 10.1107/S1600536811000882

N,N′-Bis(4-aminobenzyl)oxalamide

Juan Saulo Gonzalez-Gonzalez ^a, Francisco J Martínez-Martínez ^a, Efrén V García-Báez ^b,^*, Olivia M Franco-Hernández ^b, Itzia I Padilla-Martínez ^b

PMCID: PMC3051624 PMID: 21523071

Abstract

In the title compound, C₁₆H₁₈N₄O₂, the two carbonyl groups are in an antiperiplanar conformation with an O=C—C=O torsion angle of 173.86 (17)°. In the crystal, a pair of intermolecular N—H⋯O hydrogen bonds, forming an R ₂ ²(10) ring motif, connect the molecules into an inversion dimer. The dimers are further linked by N—H⋯N and C—H⋯π interactions, forming a zigzag chain along the b axis.

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For related structures, see: Lee & Wang (2007 ▶). For background to and applications of oxalamides, see: Martínez-Martínez et al. (1998 ▶); Padilla-Martínez et al. (2001 ▶); Nguyen et al. (2001 ▶).

Experimental

Crystal data

C₁₆H₁₈N₄O₂
M _r = 298.34
Monoclinic,
a = 10.7970 (9) Å
b = 8.0930 (8) Å
c = 17.9888 (7) Å
β = 110.151 (10)°
V = 1475.7 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.40 × 0.30 × 0.20 mm

Data collection

Bruker APEXII area-detector diffractometer
13460 measured reflections
2577 independent reflections
2041 reflections with I > 2σ(I)
R _int = 0.050

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.141
S = 1.05
2577 reflections
199 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97 and WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811000882/is2647sup1.cif

e-67-0o398-sup1.cif^{(22.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811000882/is2647Isup2.hkl

e-67-0o398-Isup2.hkl^{(124KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the C1–C6 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N4—H4A⋯N16ⁱ	0.86	2.48	3.240 (3)	147
N4—H4B⋯O9ⁱⁱ	0.86	2.35	3.196 (2)	170
N8—H8⋯N4ⁱⁱⁱ	0.86	2.31	3.085 (2)	150
N11—H11⋯O9^iv	0.86	2.27	3.015 (2)	145
C6—H6⋯Cg1ⁱⁱⁱ	0.93	2.94	3.836 (3)	162

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

The authors gratefully acknowledge financial support from the FRABA-Universidad de Colima, CONACYT 83378 and SIP-IPN.

supplementary crystallographic information

Comment

The chemical structure of oxalamides favors the formation of intra and intermolecular hydrogen bonding interactions (Martínez-Martínez et al., 1998; Padilla-Martínez et al., 2001; Nguyen et al., 2001). Herein we present the title compound, (I), a new bis-oxalamide.

The title compound (I) forms monoclinic crystals (P2₁/c, Z = 4). Carbonyl groups are antiperiplanar, with an O9—C9—C10—O10 torsion angle of 173.86 (17)°. The oxalamide group is almost planar, with an N8—C9—C10—N11 torsion angle of 171.92 (17)°. The aminobenzyl groups are twisted by 69.43 (5)° (C1—C7/N4) and 73.78 (5)° (C13—C18/N16) out of the oxalamide group mean plane (C7/N8/C9/O9/C10/O10/N11/C12) and are almost parallel to each other with an angle between the planes of 4.56 (5)°. According to graph-set notation (Bernstein et al., 1995), two S(5) rings are formed through N8—H8···O10 and N11—H11···O9 interactions. N···O distances and N—H···O angles are in the range for strong hydrogen bonding, in agreement with similar structures (Lee and Wang, 2007). The zero dimensional array is given by pairing of two molecules through self complementary strong N11—H11···O9 hydrogen bonding, to form the R²₂(10) motif characteristic of oxalamides. The molecules are connected by N8—H8···N4 and C6—H6···Cg1 into a zigzag chain running along the b axis; Cg1 is the centroid of the C1–C6 ring. Amine N4—H4A···N16 and N4—H4B···O9 hydrogen bonding interactions give the second and third dimensions, forming C(17) and C(10) chains, respectively.

Experimental

A mixture of diethyl oxalate (2 ml,14 mmol) and 4-aminobenzylamine (3.34 ml, 28 mmol) in ethanol (30 ml) was refluxed for 6 h. The suspension was filtered and the resulting solid was washed with cold ethyl alcohol to yield 3.25 g (73%) of a pale yellow solid (m.p. 250–252 °C).

IR (neat, cm^-1): 3415, 3346, 3202, 3038, 1651. Anal. calcd. for C₁₆H₁₈N₄O₂: C 64.41, H 6.08, N 18.78%; found: C 64.07, H 6.25, N 18.44%. ¹H NMR (300 MHz, DMSO_d-6, δ) CH₂ 4.11 (d, 2H), NH 9.03 (t, 1H), Aromatics: 6.46 (d, 2H), 6.90 (d, 2H), NH₂ 4.95 (s, 2H). ¹³C NMR (75.46 MHz, DMSO_d-6, δ) 42.7, 114.2, 126.3, 129.1, 148.3, 160.5. ESI MS = calc. m/z 298.14, found m/z 320.8 [M + Na]⁺.