2-Meth­oxy-3,4-diphenyl­phenol

Ilia A Guzei; Senthilvelan Annamalai; Howard E Zimmerman

doi:10.1107/S1600536809050855

. 2009 Dec 9;66(Pt 1):o72. doi: 10.1107/S1600536809050855

2-Methoxy-3,4-diphenylphenol

Ilia A Guzei ^a,^*, Senthilvelan Annamalai ^a, Howard E Zimmerman ^a

PMCID: PMC2980045 PMID: 21580173

Abstract

The title compound, C₁₉H₁₆O₂, was isolated as the major product after the solid-state photochemical reaction of 2-methoxy-4,4-diphenylcyclohexa-2,5-dienone. The dihedral angles between the central ring and pendant benzene rings are 60.76 (6) and 51.64 (6)°. The O—C vector of the methoxy group is almost perpendicular to the plane of the central ring as indicated by the C—C—O—C torsion angle of 94.89 (18)°. Hydrogen-bonded dimers are formed in the crystal structure via O—H⋯O interactions. The data were collected at room temperature on a Bruker SMART X2S diffractometer in the automated mode and processed manually thereafter.

Related literature

For the characterization of reaction products, see: Frimer et al. (1994 ▶); Matoba et al. (1985 ▶). Mogul (Bruno et al., 2002 ▶) was used for the geometrical analysis. graphic file with name e-66-00o72-scheme1.jpg

Experimental

Crystal data

C₁₉H₁₆O₂
M _r = 276.32
Monoclinic,
a = 14.312 (3) Å
b = 6.2585 (14) Å
c = 17.167 (4) Å
β = 102.930 (7)°
V = 1498.7 (6) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 300 K
0.36 × 0.30 × 0.28 mm

Data collection

Bruker SMART X2S diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007 ▶) T _min = 0.972, T _max = 0.978
13658 measured reflections
2645 independent reflections
1897 reflections with I > 2σ(I)
R _int = 0.040

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.129
S = 1.01
2645 reflections
192 parameters
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: GIS (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL and OLEX2 (Dolomanov et al., 2009 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: local programs (Guzei, 2007 ▶) and publCIF (Westrip, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809050855/tk2575sup1.cif

e-66-00o72-sup1.cif^{(18.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809050855/tk2575Isup2.hkl

e-66-00o72-Isup2.hkl^{(129.9KB, hkl)}

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
O2—H2⋯O1ⁱ	0.82	2.21	2.9043 (18)	142

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Symmetry code: (i) Inline graphic .

Acknowledgments

We gratefully acknowledge Bruker sponsorship of this publication. Support of the photochemical research by the NSF is gratefully acknowledged.

supplementary crystallographic information

Comment

The title compound (I), Fig. 1, was isolated as the major product during our studies of the solid state photochemical behavior of 2-methoxy-4,4-diphenyl-2,5-cyclohexadienone as described in the Experimental.

All bond distances and angles in (I) fall in the expected ranges according to the Mogul structural check (Bruno, et al., 2002). The dihedral angles between the C1—C6 ring and rings C8—C13 and C14—C19 are 60.76 (6)° and 51.64 (6)°, respectively. The O1—C7 vector of the methoxy group is almost perpendicular to the plane of the C1—C6 ring as indicated by the dihedral angle C2—C1—O1—C7 of 94.89 (18)°. Compound (I) forms hydrogen-bonded dimers in the solid state. The graph set notation for the dimers connected by O2—H2···O1 hydrogen bonds is R₂²(10).

Experimental

Solid state photolysis of 2-methoxy-4,4-diphenyl-2,5-cyclohexadienone (II) was studied as follows.

A thin film of (II) (0.30 g, 0.001 mol) was irradiated under nitrogen for 18 h through a CuSO₄ filter with a 400 watt medium pressure mercury lamp. The lamp was surrounded by a water-cooled immersion jacket and a cylindrical flask. The film of (II) was deposited on the inner wall of the outer flask (4 cm from the lamp) by slow evaporation of its dichloromethane solution and was dried before photolysis under nitrogen for 2 h. The resulting orange solid was chromatographed (silica gel 2.5 cm x 37 cm), eluted with hexane-CH₂Cl₂ (2:3) to give the following: band 1, 2-methoxy-4,5-diphenylphenol (III); band 2, 2-methoxy-3,4-diphenylphenol (I), band 3, 6-methoxy-5,6-diphenyl-2,4-cyclohexadienone (IV). The unreacted (band 4) cyclohexadienone (II) (0.10 g, 33%) was separated by using CH₂Cl₂—CH₃OH (9:1) elution (Scheme 1).

2-Methoxy-4,5-diphenylphenol (III) (Band 1): Recrystallization from ether-hexane gave (75 mg, 25%) colorless crystals, mp 419–421 K (Literature mp 422–423 K (Frimer et al., 1994)). ¹H NMR (CDCl₃, 300 MHz): δ 3.95 (s, 3H), 5.62 (s, 1H), 6.91 (s, 1H), 7.02 (s, 1H), 7.10–7.21 (m, 10H) p.p.m.; ¹³C NMR (CDCl₃, 75 MHz) δ 56.3, 113.3, 116.9, 126.4, 128.0, 128.1, 130.2, 130.2, 133.3, 134.1, 141.6, 142.0, 145.1, 146.1 p.p.m.

2-Methoxy-3,4-diphenylphenol (I) (Band 2): Recrystallization from CH₂Cl₂-hexane gave (90 mg, 30%) colorless crystals, mp 417–419 K. ¹H NMR (CDCl₃, 300 MHz): δ 3.29 (s, 3H), 5.88 (s, 1H), 6.99–7.04 (m, 3H), 7.08–7.17 (m, 6H), 7.20–7.24 (m, 3H) p.p.m.; ¹³C NMR (CDCl₃, 75 MHz) δ 60.7, 114.5, 126.2, 126.8, 127.1, 127.8, 128.0, 130.2, 131.1, 133.8, 134.5, 136.3, 141.3, 145.3, 148.4 p.p.m.

6-Methoxy-5,6-diphenyl-2,4-cyclohexadienone (IV) (Band 3): This was recrystallized from CH₂Cl₂-hexane mixture. Yield = 15 mg, 5%; mp 467–469 K (Literature mp 469–471 K (Matoba et al.,1985). ¹H NMR (CDCl₃, 300 MHz): δ 3.66 (s, 3H, OCH₃), 5.56 (d, J = 7.8 Hz, 1H), 5.88 (d, J = 9.9 Hz, 1H), 7.15–7.29 (m, 11H) p.p.m.; ¹³C NMR (CDCl₃, 75 MHz) δ 56.2, 69.5, 94.5, 118.8, 127.6, 128.3, 129.9, 141.0, 143.5, 171.2, 201.2 p.p.m.