Crystal structure of N-[(2-hy­droxy­naphthalen-1-yl)(4-methyl­phen­yl)meth­yl]acetamide

Sharanbasappa Khanapure; Gajanan Rashinkar; Tarulata Chhowala; Sumati Anthal; Rajni Kant

doi:10.1107/S2056989015004661

. 2015 Mar 14;71(Pt 4):o235. doi: 10.1107/S2056989015004661

Crystal structure of N-[(2-hydroxynaphthalen-1-yl)(4-methylphenyl)methyl]acetamide

Sharanbasappa Khanapure ^a, Gajanan Rashinkar ^a, Tarulata Chhowala ^b, Sumati Anthal ^c, Rajni Kant ^c,^*

PMCID: PMC4438828 PMID: 26029431

Abstract

In the title molecule, C₂₀H₁₉NO₂, the naphthalene ring system subtends a dihedral angle of 82.50 (7)° with the benzene ring and an intramolecular N—H⋯O hydrogen bond closes an S(6) ring. In the crystal, molecules are linked by O—H⋯O hydrogen bonds, which generate C(8) chains propagating in the [010] direction. The crystal structure also features weak π–π interactions [centroid–centroid separation = 3.7246 (10) Å].

Keywords: crystal structure, naphthalene, acetamide, π–π interactions, hydrogen bonding

Related literature

For background to N-(substituted phenyl)acetamides, see: Schleiss et al. (2008 ▸). For further synthetic details, see: Shaterian et al. (2008 ▸). For related structures, see: Mosslemin et al. (2007 ▸); NizamMohideen et al. (2009 ▸).

Experimental

Crystal data

C₂₀H₁₉NO₂
M _r = 305.36
Monoclinic,
a = 10.4324 (4) Å
b = 14.0786 (5) Å
c = 11.0356 (4) Å
β = 98.741 (2)°
V = 1602.01 (10) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 296 K
0.25 × 0.20 × 0.20 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▸) T _min = 0.980, T _max = 0.984
12272 measured reflections
2821 independent reflections
2391 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.122
S = 1.05
2821 reflections
209 parameters
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.16 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: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S2056989015004661/hb7375sup1.cif

e-71-0o235-sup1.cif^{(24.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015004661/hb7375Isup2.hkl

e-71-0o235-Isup2.hkl^{(135.7KB, hkl)}

Click here for additional data file.^{(6.3KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015004661/hb7375Isup3.cml

Click here for additional data file.^{(1.3MB, tif)}

. DOI: 10.1107/S2056989015004661/hb7375fig1.tif

The molecular configuration of (I). Displacement ellipsoids are drawn at the 30% probability level.

Click here for additional data file.^{(1.6MB, tif)}

b . DOI: 10.1107/S2056989015004661/hb7375fig2.tif

The packing arrangement of molecules viewed down the b axis.

CCDC reference: 959797

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
N1H1AO1	0.86	2.20	2.7396(16)	121
O1H1BO2ⁱ	0.82	1.85	2.6498(15)	165

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

S1. Comment

1-Amidoalkyl-2-naphthol scaffolds are of significant medicinal relevance since they can be converted into hypertensive and bradycardiac active 1-aminoalkyl-2-naphthols by amine hydrolysis reactions [Schleiss et al., 2008]. As part of our studies in this area, we now describe the synthesis and structure of the title compound, (I).

The conformation of (I), together with the atom-numbering scheme, is shown in Fig. 1. In the structure, all bond lengths are comparable with those in previously reported structures (Mosslemin et al., 2007, NizamMohideen et al., 2009). Atom O1 deviating by 0.009 (1) Å from the least squares plane of the naphthalene ring. The dihedral angle between the naphthalene and benzene ring(C2/C3/C4/C5/C7/C8) is 82.5 (10)°. Examination of non bonded contacts reveals the presence of one N—H···O intramolecular hydrogen bond between N1 and hydroxyl atom O1 via H1 which results in the formation of pseudo six membered ring with S(6) graph-set motif. In this crystal, adjacent molecules are interconnected through O—H···O hydrogen bonds, which link the molecules into chains running along b axis. The crystal structure is further stabilized by π-π interactions between phenyl rings [centroid-centroid separation = 3.725 Å, interplaner spacing = 3.571 Å and centroid shift = 1.06 Å] where Cg1 and Cg2 represents the centre of gravity of rings (C2/C3/C4/C5/C7/C8) and (C11—C16), respectively.

S2. Experimental

The compound N-[(phenyl)-(2-hydroxy-naphthalen-1-yl)- methyl]acetamide was synthesized by using benzaldehyde, 2-naphthol and acetamide by using Cp2ZrCl2 as a catalyst at room temperature. A mixture of 2-naphthol (1 mmol), benzaldehyde (1 mmol), acetamide (1.2 mmol) and zirconocene dichloride (20 mol%) was stirred in ethylene dichloride (5 ml) at room temperature for 10 h. After completion of reaction, as indicated by TLC, the reaction mixture was quenched in cold water. The obtained crude solid was filtered and purified by column chromatography on silica gel (Merck. 60–120 mesh, ethyl acetate: hexane)to afford the pure product in 72% yield. The identity of the compound was ascertained on the basis of FTIR, 1HNMR and 13CNMR spectroscopy as well as by mass spectrometry. The physical and spectroscopic data are consistent with the proposed structure and are in harmony with the literature values (Shaterian et al., 2008). The IR spectrum exhibits broad absorption band at 3435 for O—H stretching and a sharp band at 3230 for N—H stretching of amide. The presence of amide group was apparent from strong absorptions at 1638 (C=O stretching) and 1597 (C—N stretching)·The 1H NMR (300 MHz, DMSO-d6) spectra of N-[(2-Hydroxynaphthalen-1-yl)(4-methylphenyl) methyl]acetamideexhibited singlets at δ 2.01 and 2.13 for protons of two methylgropus. The signals for amidic N—H and phenolic O—H protons appeared at 8.20 (s) and 9,96 (s) respectively. The two multiplets in the region 7.00–7.82 were assigned to ten aromatic protons and one methine proton. The proton decoupled 13 C NMR (75 MHz, DMSO-d6)spectra of N-[(2-Hydroxynaphthalen-1-yl) (4-methylphenyl)methyl]acetamidedisplay 19 distinct signals at 170.26, 153.43,139.67, 135.80, 132.64, 129.72, 129.08,128.86, 126.92,126.36, 123.53,122.98, 119.18, 118.82which is in agreement with the proposed structure. The Mass spectrum MS (EI): of this compound displayed the molecular ion peak at m/z = 306 (M+) which is in agreement with the proposed structure.