N-[4-(4-Nitro­phen­oxy)phen­yl]penta­n­amide

Asifan Nigar; Zareen Akhter; Vickie McKee; Rizwan Hussain

doi:10.1107/S1600536812036744

. 2012 Aug 31;68(Pt 9):o2816. doi: 10.1107/S1600536812036744

N-[4-(4-Nitrophenoxy)phenyl]pentanamide

Asifan Nigar ^a, Zareen Akhter ^a,^*, Vickie McKee ^b, Rizwan Hussain ^c

PMCID: PMC3435840 PMID: 22969686

Abstract

The asymmetric unit of the title compound, C₁₇H₁₈N₂O₄, contains two independent molecules (A and B) differing principally in the conformations of the alkyl chains, anti for molecule A and gauche for molecule B. The dihedral angles between the aromatic rings are 82.51 (6) and 82.25 (6)° in the two molecules. In the crystal, amide–amide interactions (as N—H⋯O=C) results in distinct chains of A and B molecules running parallel to the a-axis direction. C—H⋯O interactions also occur.

Related literature

For the related structures N-(4-(4-nitrophenoxy)phenyl)propionamide, 4-nitro-N-(4-(4-nitrophenoxy)phenyl)benzamide and N-[4-(4-nitrophenoxy)phenyl]acetamide see: Nigar et al. (2008 ▶), Butt et al. (2007 ▶) and Nigar et al. (2012 ▶), respectively.

Experimental

Crystal data

C₁₇H₁₈N₂O₄
M _r = 314.33
Triclinic,
a = 4.9776 (5) Å
b = 10.1139 (10) Å
c = 30.572 (3) Å
α = 92.069 (2)°
β = 90.087 (2)°
γ = 91.060 (2)°
V = 1537.8 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 150 K
0.33 × 0.32 × 0.13 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2008a ▶) T _min = 0.968, T _max = 0.987
17614 measured reflections
6018 independent reflections
4664 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.135
S = 1.09
6018 reflections
415 parameters
H-atom parameters constrained
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker 1998 ▶); cell refinement: SAINT (Bruker 1998 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008b ▶); molecular graphics: SHELXTL (Sheldrick, 2008b ▶) and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812036744/gg2093sup1.cif

e-68-o2816-sup1.cif^{(34KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812036744/gg2093Isup2.hkl

e-68-o2816-Isup2.hkl^{(294.6KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812036744/gg2093Isup3.cml

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2A—H2A1⋯O4A ⁱ	0.88	2.08	2.955 (2)	178
N2B—H2B1⋯O4B ⁱ	0.88	2.05	2.929 (2)	174
C3A—H3A⋯O1A ⁱⁱ	0.95	2.49	3.341 (3)	150
C5A—H5A⋯O2A ⁱⁱⁱ	0.95	2.62	3.376 (3)	137
C3B—H3B⋯O1B ^iv	0.95	2.49	3.360 (3)	153

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

Acknowledgments

The authors are grateful to the Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan, and the Chemistry Department, Loughborough University, Loughborough, England, for providing laboratory and analytical facilities.

supplementary crystallographic information

Comment

The crystal structure of N-[4-(4-Nitrophenoxy)phenyl]acetamide (Nigar et al.2012) has been published and is related to that of the title compound, (Fig. 1).

There are two independent molecules in the asymmetric unit, differing primarily in the conformations of the alkyl chains (Fig. 1). The unsaturated sections of the molecules have quite similar orientations, with interplanar angles between the mean planes of the two aromatic rings of 82.51 (6)° for the molecule with 'A' labels and 82.25 (6)° for the molecule with 'B' labels.

Each molecule is linked to two crystallographically identical molecules via H-bonding involving the amide groups (N—H ···O═C distances 2.956 (2) Å and 2.929 (2) Å for N2A···O4A and N2B···O4B respectively, both under symmetry operation x - 1, y, z). This results in separate H-bonded chains of 'A' and 'B' molecules running parallel to the a axis (Fig 2, Table 3).

The nitro groups are involved in weaker H-bonding to aromatic C—H groups. Each molecule 'A' makes four bonds with identical neighbours, linking the chains together (C3A—H···O1A 3.341 (3) Å under -x, 2 - y, 1 - z and C5A—H···O2A 3.376 (3) Å under 1 - x, 3 - y, 1 - z, Fig 3, Table 3). Molecule 'B' only forms one such interaction; C3B···O1B 3.360 (3) Å under -1 - x,-y,-z (Fig 4, Table 3).

Experimental

Synthesis ofN-[4-(4'-Nitrophenoxy)phenyl] pentanamide

A mixture of 2.50 g (25 mmol) 4-aminophenol, 3.46 g (25 mmol) anhydrous K₂CO₃ and 2.65 ml (25 mmol) 4-nitrofluorobenzene in 35 ml DMF was heated at 373 K for 18 h in an inert atmosphere. After cooling to room temperature, the reaction mixture was poured into 400 ml of water to yield a yellow solid. The product was filtered, dried, and then recrystallized from n-hexane (yield, 86%). In the second step, pentanoic acid and thionylchloride were refluxed in equimolar amounts for 30 min. The excessive amount of thionylchloride was rotary evaporated and pentanoylchloride obtained was reacted with 4-(4-nitrophenoxy) aniline, as prepared in the first step, in appropriate molar ratios. THF was used as solvent and 1 ml of triethylamine was also added for 1.0 g of 4-(4-nitrophenoxy) aniline. The reaction mixture was refluxed for 2 h under inert conditions and allowed to stand overnight at room temperature. The settled salt was filtered off and filtrate was evaporated to get the crude product, which was recrystallized from toluene (89% yield, m.p. 390 K)