2-(4-Meth­oxy-2-methyl­anilino)-1,2-diphenyl­ethanone

Hakan Arslan; Oztekin Algul; Selin Zirek; Ozden Tari; Aydın Demircan; Kenneth I Hardcastle

doi:10.1107/S1600536811015960

. 2011 May 7;67(Pt 6):o1303. doi: 10.1107/S1600536811015960

2-(4-Methoxy-2-methylanilino)-1,2-diphenylethanone

Hakan Arslan ^a,^b,^*, Oztekin Algul ^c, Selin Zirek ^c, Ozden Tari ^c, Aydın Demircan ^d, Kenneth I Hardcastle ^a

PMCID: PMC3120400 PMID: 21754706

Abstract

The title compound, C₂₂H₂₁NO₂, was synthesized from 4-methoxy-2-methylaniline and 2-hydroxy-1,2-diphenylethanone. In the title compound, the C—C—C—N—C backbone adopts an all-trans conformation. The crystal structure is stabilized by weak intermolecular C—H⋯O hydrogen-bond interactions.

Related literature

For the synthesis and similar structures, see: Au & Tafeenko (1986 ▶, 1987 ▶); Batsanov et al., (2006 ▶). For general background to these structures, see: Batsanov et al. (2006 ▶); Abdulla et al. (1985 ▶). For bond-length data, see: Allen et al. (1987 ▶). For geometrical analysis, see: Bruno et al. (2002 ▶).

Experimental

Crystal data

C₂₂H₂₁NO₂
M _r = 331.40
Monoclinic,
a = 12.570 (12) Å
b = 8.009 (8) Å
c = 18.091 (17) Å
β = 100.544 (15)°
V = 1791 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 173 K
0.21 × 0.19 × 0.15 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.984, T _max = 0.988
28799 measured reflections
4122 independent reflections
2935 reflections with I > 2σ(I)
R _int = 0.055

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.112
S = 1.05
4122 reflections
226 parameters
H-atom parameters constrained
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Data collection: SMART (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: OLEX2 (Dolomanov et al., 2009 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶), OLEX2, publCIF (Westrip, 2010 ▶) and Mercury (Macrae et al., 2006 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811015960/hg5030sup1.cif

e-67-o1303-sup1.cif^{(20.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811015960/hg5030Isup2.hkl

e-67-o1303-Isup2.hkl^{(202KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811015960/hg5030Isup3.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
C11—H11A⋯O1ⁱ	0.95	2.48	3.352 (4)	153

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was supported by the Mersin University Research Fund [Project No. BAP-SBE FK (SZ) 2008–8 YL].

supplementary crystallographic information

Comment

A few 1-arylanilinoethanone derivatives have been structurally charactized because of their importance in synthesis or because of their interesting charge-transfer properties (Abdulla et al., 1985). We found only four structurally similar compounds (Au & Tafeenko, 1987; Au & Tafeenko, 1986; Batsanov et al., 2006) in the Cambridge Structural Database (CSD CONQUEST 1.11, B4; Bruno et al., 2002).

Compound I was synthesized by the HCl acid-catalyzed reaction of a benzoin derivative to 4-methoxy-2-methylaniline (Scheme 1) resulting in the title compound, 2-((4-methoxy-2-methylphenyl)amino)-1,2-diphenylethanone, I, Figure 1, its structure was determined by X-ray crystallography.

The molecular structure of the title compound contains two phenyl rings and one substituted aniline ring connected by a –C(O)—C– linker. The dihedral angle between the two phenyl rings is 87.78 (7) ° and the dihedral angle between the substitute aniline and phenyl rings are 55.30 (7) and 84.57 (7) °, respectively. In adition, in the title compound, the C2—C1—C8—N1—C15 backbone adopts an all-trans conformation (Au & Tafeenko, 1987; Au & Tafeenko, 1986; Batsanov et al., 2006).

The C—N bond lengths C8—N1 and C15—N1 are shorter than the normal C—N single-bond length of about 1.48 Å. The shortening of these C—N bonds reveals the effects of some conjugation in this part of the molecule. All other bond lengths fall within the expected ranges (Allen et al., 1987).

Intramolecular hydrogen bonding N1–H1A···O1 with N–H 0.88 Å, H···O 2.22 Å, N–H···O 107 ° results in the formation of a five membered ring in the O1—C1—C8—N1–H1A plane. The crystal packing is dominated by weak intermolecular C11—H11A···O1 (x, 1 + y, z) hydrogen bonds, with H···O = 2.48 Å and a C—H···O angle of 153 ° (Figure 2).

Experimental

A mixture of 4-methoxy-2-methylaniline (15 mmol), 2-hydroxy-1,2-diphenylethanone (5 mmol) and 1 ml conc. HCl in 20 ml of ethanol were refluxed for 5 h (Figure 3). After reaction was complete, the mixture was allowed to cool to room temperature, poured into cold water (20 ml) and finally extracted with CH₂Cl₂ (3x15 ml). The organic layer was dried over magnesium sulfate and the solvent removed under reduced pressure to yield a crude product that was purified by recrystallization in ethyl acetate. 2-((4-methoxy-2-methylphenyl)amino)-1,2-diphenylethanone: Yield: 1.20 g, 46%. M.p.: 110–112 °C. ¹H NMR (DMSO-d₆) δ: 8.18–8.16 (d, 2H, Ar—H (C3, C7)), 7.62 (t, 1H, Ar—H (C5)), 7.56–7.49 (m, 4H, Ar—H (C4, C6, C11, C13)), 7.30–7.26 (m, 2H, Ar—H (C10, C14)), 7.16 (t, 1H, Ar—H (C12)), 6.70–6.68 (d, J=4.8 Hz, 1H, Ar—H (C19)), 6.67 (s, 1H, Ar—H (C17)), 6.57–6.55 (d, J=8 Hz, 1H, Ar—H (C20)), 6.46–6.44 (d, J=8 Hz, 1H, Ar—H (C8)), 5.19–5.17 (d, J=8 Hz, 1H, NH), 3.60 (s, 3H, OCH₃), 2.22 (s, 3H, CH₃). ¹³C NMR (400 MHz, p.p.m.) δ: 17.5 (CH₃), 55.1 (OCH₃), 61.5 (C8), 111.2 (C19), 112.5 (C20), 116.4 (C17), 123.9 (C16), 127.6, 128.1, 128.6, 128.7, 128.8 (C), 133.7 (C5), 134.7 (C2), 138.1 (C9), 138.3 (C15), 151.1 (C18), 197.6 (C9). Anal. Calc. for C₂₂H₂₁NO₂: C, 79.73; H, 6.39; N, 4.23%. Found: C, 79.70; H, 6.21; N, 4.19%.