organic compounds
of 4-(4-methoxyphenoxy)benzaldehyde
aFakultät Chemie und Chemische Biologie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany
*Correspondence e-mail: hans.preut@tu-dortmund.de
The title compound, C14H12O3, was synthesized via the nucleophilic addition of 4-methoxyphenol to 4-fluorobenzaldehyde. The dihedral angle between the least-squares planes of the benzene rings is 71.52 (3)° and the C—O—C angle at the central O atom is 118.82 (8)°. In the crystal, weak C—H⋯O hydrogen bonds link the molecules to generate supramolecular layers in the bc plane. The layers are linked by weak C—H⋯π interactions.
CCDC reference: 1439095
1. Related literature
For the synthesis of 4-(4-methoxyphenoxy)benzaldehyde in an undergraduate laboratory course, see: Taber & Brannick (2015). For the synthesis of 4-aryloxybenzaldehydes and acetophenones, see: Yeager & Schissel (1991).
2. Experimental
2.1. Crystal data
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2.3. Refinement
|
Data collection: CrysAlis PRO (Oxford Diffraction, 2008); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015); molecular graphics: SHELXP2014 (Sheldrick, 2008); software used to prepare material for publication: SHELXL2013 and PLATON (Spek, 2009).
Supporting information
CCDC reference: 1439095
https://doi.org/10.1107/S2056989015022707/tk5411sup1.cif
contains datablocks I, 3352b. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989015022707/tk5411Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2056989015022707/tk5411Isup3.cml
In a glass test tube (160x16 mm) 4-fluorobenzaldehyde (II) (C7H5FO, M =124.11 g/mol, 250 mg, 2.01 mmol, 1 eq), 4-methoxyphenol (III) (C7H8O2, M = 124.14 g/mol, 250 mg, 2.01 mmol, 1 eq) and potassium carbonate (K2CO3, M = 138.20 g/mol, 550 mg, 3.98 mmol, 2 eq) were suspended in dimethyl sulfoxide (2 ml, 1 ml/mmol). The reaction mixture was heated to 413 K and stirred at this temperature for 45 min. After consumption of the starting materials, the oil bath was removed and the suspension was cooled to room temperature. The reaction mixture was diluted with water (6 ml, 3 ml/mmol) and stirred at ambient temperature for 30 min. The resulting suspension was tranferred into a separatory funnel with water and then extracted with ethyl acetate (3x). The combined organic phases were extracted with saturated aqueous sodium chloride solution (5x) and dried over MgSO4. After removal of the solvents under reduced pressure, the light brown viscous oil was dissolved in dichloromethane (2 ml) and transferred into a wide-necked flask. The solution was diluted with n-heptane (1 ml) and the solvent was allowed to evaporate over three days. Crystals slowly form and grow, coating the sides of the flask. The large pale yellow crystals were washed with n-heptane (1 ml) and dried in vacuo to deliver 4-(4-methoxyphenoxy)benzaldehyde (I) (C14H12O3, M = 228.25 g/mol, 440 mg, 1.93 mmol, 96%). Recrystallization of a small amount of (I) from n-heptane by slow evaporation over one week provided clear colourless crystals. Rf 0.48 (cyclohexane/ethyl acetate 5/1); m.p. 323–325 K (n-heptane) [m.p. 332.5–333.5 K (n-hexane) (Yeager & Schissel, 1991)]; 1H NMR (CDCl3, 500 MHz) δ 3.83 (s, 3H), 6.92–6.95 (m, 2H), 6.99–7.05 (m, 4H), 7.81–7.83 (m, 2H), 9.90 (s, 1H); 13C NMR (CDCl3, 126 MHz) δ 55.8 (CH3), 115.3 (CH), 116.9 (CH), 122.0 (CH), 131.0 (C), 132.1 (CH), 148.3 (C), 157.0 (C), 164.2 (C), 190.9 (CH); IR ν 3005 (w), 2965 (w), 2835 (w), 2745 (w), 1680 (s), 1595 (m), 1575 (s), 1495 (s), 1440 (m), 1230 (s), 1195 (s), 1150 (s), 1100 (m), 1085 (s), 875 (m), 845 (m), 830 (s), 785 (s), 745 (m), 565 (m), 525 (m), 510 (s).
H-atoms attached to C, except those in CH3, were placed in calculated positions (C—H = 0.95 Å and Uiso(H) = 1.2 Ueq(C)). CH3 hydrogen atoms, which were taken from a Fourier map, were allowed to rotate but not to tip (C—H = 0.98 Å and Uiso(H) = 1.5 Ueq(C)).
As part of an evaluation of single step experiments for an undergraduate laboratory course, we came across a literature protocol that describes the preparation of crystalline 4-aryloxybenzaldehyde by nucleophilic aromatic substitution (Taber & Brannick, 2015). The reaction of 4-fluorobenzaldehyde (II) with 4-methoxyphenol (III) in the presence of potassium carbonate in dimethyl sulfoxide provided 4-(4-methoxyphenoxy)benzaldehyde (I) as large pale yellow crystals. The recrystallization of a small amount of (I) from n-heptane provided clear colourless crystals, suitable for X-ray analysis. In our hands, the literature protocol failed to deliver precipitated crude product upon dilution of the reaction mixture with water and subsequent drying on filter paper. Our modified protocol is characterized by a general aqueous work-up procedure, including extraction with brine for removal of dimethyl sulfoxide.
For the synthesis of 4-(4-methoxyphenoxy)benzaldehyde in an undergraduate laboratory course, see: Taber & Brannick (2015). For the synthesis of 4-aryloxybenzaldehydes and acetophenones, see: Yeager & Schissel (1991).
Data collection: CrysAlis PRO (Oxford Diffraction, 2008); cell
CrysAlis PRO (Oxford Diffraction, 2008); data reduction: CrysAlis PRO (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015); molecular graphics: SHELXP2014 (Sheldrick, 2008); software used to prepare material for publication: SHELXL2013 (Sheldrick, 2015) and PLATON (Spek, 2009).Fig. 1. The molecular structure of the title compound, showing the labelling of all non-H atoms. Displacement ellipsoids are shown at the 50% probability level. |
C14H12O3 | Dx = 1.360 Mg m−3 |
Mr = 228.24 | Melting point = 323–325 K |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 12.1297 (7) Å | Cell parameters from 10396 reflections |
b = 7.6581 (4) Å | θ = 3.2–31.0° |
c = 12.3577 (7) Å | µ = 0.10 mm−1 |
β = 103.769 (6)° | T = 173 K |
V = 1114.92 (11) Å3 | Block, colourless |
Z = 4 | 0.56 × 0.40 × 0.30 mm |
F(000) = 480 |
Oxford Diffraction Xcalibur2 CCD diffractometer | 2967 independent reflections |
Radiation source: fine-focus sealed tube | 2551 reflections with I > 2σ(I) |
Detector resolution: 16.0560 pixels mm-1 | Rint = 0.023 |
ω und ψ scan | θmax = 29.0°, θmin = 3.2° |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008) | h = −16→16 |
Tmin = 0.808, Tmax = 1.000 | k = −10→10 |
10049 measured reflections | l = −16→14 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.112 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0604P)2 + 0.2707P] where P = (Fo2 + 2Fc2)/3 |
2967 reflections | (Δ/σ)max < 0.001 |
155 parameters | Δρmax = 0.28 e Å−3 |
0 restraints | Δρmin = −0.22 e Å−3 |
C14H12O3 | V = 1114.92 (11) Å3 |
Mr = 228.24 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.1297 (7) Å | µ = 0.10 mm−1 |
b = 7.6581 (4) Å | T = 173 K |
c = 12.3577 (7) Å | 0.56 × 0.40 × 0.30 mm |
β = 103.769 (6)° |
Oxford Diffraction Xcalibur2 CCD diffractometer | 2967 independent reflections |
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008) | 2551 reflections with I > 2σ(I) |
Tmin = 0.808, Tmax = 1.000 | Rint = 0.023 |
10049 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.112 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.28 e Å−3 |
2967 reflections | Δρmin = −0.22 e Å−3 |
155 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
O1 | 1.04659 (7) | 0.20198 (13) | 0.46684 (7) | 0.0345 (2) | |
C1 | 1.03112 (9) | 0.22947 (15) | 0.36759 (9) | 0.0254 (2) | |
H1A | 1.0880 | 0.2933 | 0.3435 | 0.030* | |
O2 | 0.65559 (6) | 0.00429 (11) | 0.03836 (6) | 0.02476 (19) | |
C2 | 0.93213 (9) | 0.17254 (14) | 0.28176 (8) | 0.0207 (2) | |
O3 | 0.60491 (7) | 0.07872 (11) | −0.41611 (6) | 0.02479 (19) | |
C3 | 0.84285 (9) | 0.07946 (14) | 0.30868 (8) | 0.0207 (2) | |
H3A | 0.8453 | 0.0524 | 0.3842 | 0.025* | |
C4 | 0.75139 (9) | 0.02708 (14) | 0.22570 (8) | 0.0204 (2) | |
H4A | 0.6902 | −0.0343 | 0.2440 | 0.025* | |
C5 | 0.74924 (8) | 0.06494 (13) | 0.11433 (8) | 0.0191 (2) | |
C6 | 0.83733 (9) | 0.15660 (14) | 0.08603 (8) | 0.0225 (2) | |
H6A | 0.8354 | 0.1817 | 0.0103 | 0.027* | |
C7 | 0.92811 (9) | 0.21065 (14) | 0.17041 (9) | 0.0233 (2) | |
H7A | 0.9884 | 0.2745 | 0.1522 | 0.028* | |
C8 | 0.65010 (9) | 0.02527 (14) | −0.07551 (8) | 0.0210 (2) | |
C9 | 0.56903 (9) | 0.13878 (14) | −0.13564 (9) | 0.0221 (2) | |
H9A | 0.5228 | 0.2056 | −0.0990 | 0.026* | |
C10 | 0.55637 (9) | 0.15361 (14) | −0.24972 (9) | 0.0221 (2) | |
H10A | 0.5012 | 0.2310 | −0.2916 | 0.027* | |
C11 | 0.62441 (8) | 0.05530 (13) | −0.30341 (8) | 0.0198 (2) | |
C12 | 0.70607 (9) | −0.05710 (14) | −0.24197 (9) | 0.0228 (2) | |
H12A | 0.7531 | −0.1232 | −0.2781 | 0.027* | |
C13 | 0.71864 (9) | −0.07229 (14) | −0.12726 (9) | 0.0239 (2) | |
H13A | 0.7739 | −0.1491 | −0.0849 | 0.029* | |
C14 | 0.66492 (10) | −0.03182 (16) | −0.47516 (9) | 0.0280 (2) | |
H14A | 0.7466 | −0.0111 | −0.4488 | 0.042* | |
H14B | 0.6412 | −0.0062 | −0.5550 | 0.042* | |
H14C | 0.6482 | −0.1542 | −0.4622 | 0.042* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0325 (4) | 0.0469 (5) | 0.0221 (4) | −0.0060 (4) | 0.0023 (3) | −0.0031 (4) |
C1 | 0.0219 (5) | 0.0302 (6) | 0.0241 (5) | −0.0030 (4) | 0.0057 (4) | −0.0041 (4) |
O2 | 0.0225 (4) | 0.0336 (4) | 0.0178 (4) | −0.0075 (3) | 0.0041 (3) | 0.0004 (3) |
C2 | 0.0216 (5) | 0.0215 (5) | 0.0194 (5) | 0.0002 (4) | 0.0058 (4) | −0.0017 (4) |
O3 | 0.0275 (4) | 0.0287 (4) | 0.0177 (4) | 0.0030 (3) | 0.0047 (3) | −0.0011 (3) |
C3 | 0.0238 (5) | 0.0228 (5) | 0.0168 (4) | 0.0009 (4) | 0.0073 (4) | 0.0002 (4) |
C4 | 0.0205 (5) | 0.0217 (5) | 0.0211 (5) | −0.0012 (4) | 0.0088 (4) | 0.0007 (4) |
C5 | 0.0194 (5) | 0.0192 (5) | 0.0187 (5) | 0.0004 (3) | 0.0042 (4) | −0.0005 (4) |
C6 | 0.0256 (5) | 0.0241 (5) | 0.0185 (5) | −0.0027 (4) | 0.0067 (4) | 0.0034 (4) |
C7 | 0.0236 (5) | 0.0254 (5) | 0.0222 (5) | −0.0046 (4) | 0.0079 (4) | 0.0013 (4) |
C8 | 0.0209 (5) | 0.0241 (5) | 0.0175 (4) | −0.0053 (4) | 0.0037 (4) | −0.0010 (4) |
C9 | 0.0195 (5) | 0.0233 (5) | 0.0238 (5) | −0.0010 (4) | 0.0061 (4) | −0.0044 (4) |
C10 | 0.0192 (5) | 0.0229 (5) | 0.0227 (5) | 0.0013 (4) | 0.0020 (4) | −0.0011 (4) |
C11 | 0.0205 (5) | 0.0203 (5) | 0.0183 (4) | −0.0035 (4) | 0.0040 (4) | −0.0016 (4) |
C12 | 0.0228 (5) | 0.0234 (5) | 0.0233 (5) | 0.0023 (4) | 0.0074 (4) | −0.0010 (4) |
C13 | 0.0224 (5) | 0.0249 (5) | 0.0235 (5) | 0.0023 (4) | 0.0036 (4) | 0.0033 (4) |
C14 | 0.0323 (6) | 0.0309 (6) | 0.0232 (5) | 0.0002 (5) | 0.0115 (4) | −0.0027 (4) |
O1—C1 | 1.2142 (14) | C6—H6A | 0.9500 |
C1—C2 | 1.4664 (14) | C7—H7A | 0.9500 |
C1—H1A | 0.9500 | C8—C13 | 1.3826 (15) |
O2—C5 | 1.3711 (12) | C8—C9 | 1.3881 (15) |
O2—C8 | 1.4021 (12) | C9—C10 | 1.3861 (14) |
C2—C7 | 1.3962 (14) | C9—H9A | 0.9500 |
C2—C3 | 1.4010 (14) | C10—C11 | 1.3959 (14) |
O3—C11 | 1.3678 (12) | C10—H10A | 0.9500 |
O3—C14 | 1.4254 (13) | C11—C12 | 1.3931 (14) |
C3—C4 | 1.3791 (14) | C12—C13 | 1.3940 (14) |
C3—H3A | 0.9500 | C12—H12A | 0.9500 |
C4—C5 | 1.4006 (13) | C13—H13A | 0.9500 |
C4—H4A | 0.9500 | C14—H14A | 0.9800 |
C5—C6 | 1.3909 (14) | C14—H14B | 0.9800 |
C6—C7 | 1.3873 (14) | C14—H14C | 0.9800 |
O1—C1—C2 | 125.60 (10) | C13—C8—O2 | 120.81 (9) |
O1—C1—H1A | 117.2 | C9—C8—O2 | 117.86 (9) |
C2—C1—H1A | 117.2 | C10—C9—C8 | 119.25 (10) |
C5—O2—C8 | 118.82 (8) | C10—C9—H9A | 120.4 |
C7—C2—C3 | 119.52 (9) | C8—C9—H9A | 120.4 |
C7—C2—C1 | 118.77 (10) | C9—C10—C11 | 120.29 (9) |
C3—C2—C1 | 121.71 (9) | C9—C10—H10A | 119.9 |
C11—O3—C14 | 117.25 (8) | C11—C10—H10A | 119.9 |
C4—C3—C2 | 120.13 (9) | O3—C11—C12 | 124.34 (9) |
C4—C3—H3A | 119.9 | O3—C11—C10 | 115.76 (9) |
C2—C3—H3A | 119.9 | C12—C11—C10 | 119.89 (9) |
C3—C4—C5 | 119.60 (9) | C11—C12—C13 | 119.82 (10) |
C3—C4—H4A | 120.2 | C11—C12—H12A | 120.1 |
C5—C4—H4A | 120.2 | C13—C12—H12A | 120.1 |
O2—C5—C6 | 124.03 (9) | C8—C13—C12 | 119.54 (9) |
O2—C5—C4 | 114.91 (9) | C8—C13—H13A | 120.2 |
C6—C5—C4 | 121.05 (9) | C12—C13—H13A | 120.2 |
C7—C6—C5 | 118.78 (9) | O3—C14—H14A | 109.5 |
C7—C6—H6A | 120.6 | O3—C14—H14B | 109.5 |
C5—C6—H6A | 120.6 | H14A—C14—H14B | 109.5 |
C6—C7—C2 | 120.91 (10) | O3—C14—H14C | 109.5 |
C6—C7—H7A | 119.5 | H14A—C14—H14C | 109.5 |
C2—C7—H7A | 119.5 | H14B—C14—H14C | 109.5 |
C13—C8—C9 | 121.21 (9) | ||
O1—C1—C2—C7 | −178.37 (11) | C5—O2—C8—C13 | 71.52 (13) |
O1—C1—C2—C3 | 0.79 (18) | C5—O2—C8—C9 | −112.38 (11) |
C7—C2—C3—C4 | −0.45 (16) | C13—C8—C9—C10 | 0.34 (15) |
C1—C2—C3—C4 | −179.60 (10) | O2—C8—C9—C10 | −175.74 (9) |
C2—C3—C4—C5 | 1.06 (16) | C8—C9—C10—C11 | 0.04 (15) |
C8—O2—C5—C6 | 4.13 (15) | C14—O3—C11—C12 | 6.25 (15) |
C8—O2—C5—C4 | −175.51 (9) | C14—O3—C11—C10 | −174.01 (9) |
C3—C4—C5—O2 | 178.84 (9) | C9—C10—C11—O3 | 179.69 (9) |
C3—C4—C5—C6 | −0.82 (16) | C9—C10—C11—C12 | −0.56 (15) |
O2—C5—C6—C7 | −179.68 (10) | O3—C11—C12—C13 | −179.58 (9) |
C4—C5—C6—C7 | −0.06 (16) | C10—C11—C12—C13 | 0.69 (15) |
C5—C6—C7—C2 | 0.69 (16) | C9—C8—C13—C12 | −0.21 (16) |
C3—C2—C7—C6 | −0.44 (16) | O2—C8—C13—C12 | 175.76 (9) |
C1—C2—C7—C6 | 178.74 (10) | C11—C12—C13—C8 | −0.31 (16) |
Cg1 and Cg2 are the centroids of the C2–C7 and C8–C13 rings, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C13—H13A···O1i | 0.95 | 2.58 | 3.5129 (14) | 167 |
C7—H7A···O1ii | 0.95 | 2.56 | 3.2500 (14) | 130 |
C1—H1A···Cg1iii | 0.95 | 2.73 | 3.5453 (12) | 145 |
C10—H10A···Cg2iv | 0.95 | 2.88 | 3.7465 (12) | 152 |
Symmetry codes: (i) −x+2, y−1/2, −z+1/2; (ii) x, −y+1/2, z−1/2; (iii) −x+2, y+1/2, −z+1/2; (iv) −x+1, y+1/2, −z−1/2. |
Cg1 and Cg2 are the centroids of the C2–C7 and C8–C13 rings, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C13—H13A···O1i | 0.95 | 2.58 | 3.5129 (14) | 167 |
C7—H7A···O1ii | 0.95 | 2.56 | 3.2500 (14) | 130 |
C1—H1A···Cg1iii | 0.95 | 2.73 | 3.5453 (12) | 145 |
C10—H10A···Cg2iv | 0.95 | 2.88 | 3.7465 (12) | 152 |
Symmetry codes: (i) −x+2, y−1/2, −z+1/2; (ii) x, −y+1/2, z−1/2; (iii) −x+2, y+1/2, −z+1/2; (iv) −x+1, y+1/2, −z−1/2. |
Acknowledgements
The TU Dortmund is greatefully acknowledged for financial support.
References
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As part of an evaluation of single step experiments for an undergraduate laboratory course, we came across a literature protocol that describes the preparation of crystalline 4-aryloxybenzaldehyde by nucleophilic aromatic substitution (Taber & Brannick, 2015). The reaction of 4-fluorobenzaldehyde (II) with 4-methoxyphenol (III) in the presence of potassium carbonate in dimethyl sulfoxide provided 4-(4-methoxyphenoxy)benzaldehyde (I) as large pale yellow crystals. The recrystallization of a small amount of (I) from n-heptane provided clear colourless crystals, suitable for X-ray analysis. In our hands, the literature protocol failed to deliver precipitated crude product upon dilution of the reaction mixture with water and subsequent drying on filter paper. Our modified protocol is characterized by a general aqueous work-up procedure, including extraction with brine for removal of dimethyl sulfoxide.