610 JOURNAL OF CHEMICAL RESEARCH 2009
Table 4 Direct acylation of phenol derivatives (1 mmol) and carboxylic acids (1 mmol) catalysed by Yb(OTf)3 (0.05 mmol)
Entry
R1
R2
Yield/%
8:9
1
2
3
4
5
6
H
PhCH2
n-C3H7
n-C7H15
PhCH2
n-C3H7
n-C7H15
81
55
72
78
50
92
8a:9a = 100:0
8b:9b = 1:9
8c:9c = 1:8
8d:9d = 100:0
8e:9e = 1:8
8f:9f = 1:8
H
H
CH3
CH3
CH3
1-(1-Hydroxynaphthalen-2-yl)octan-1-one (6b): Pale yellow solid;27
m.p.66–67°C. H NMR d: 0.89 (t, 3H, J = 8.8 Hz), 1.29–1.49 (m,
carried out by using a catalytic amount of Yb(OTf)3
under solvent-free conditions to afford the corresponding
hydroxyaryl ketones. The notable advantages are the
application to a wide variety of carboxylic acids, non-toxic
and inexpensive materials, operational simplicity, solvent-free
conditions, and an easy and clean work-up.
1
8H), 1.76–1.83 (m, 2H), 3.05 (t, 2H, J = 7.2 Hz), 7.26 (d, 1H,
J = 8.0 Hz), 7.53 (t, 1H, J = 7.6 Hz), 7.62 (t, 1H, J = 7.6 Hz), 7.68 (d,
1H, J = 8.8 Hz), 7.75 (d, 1H, J = 8.0 Hz), 8.46 (d, 1H, J = 8.0 Hz),
14.17 (s,1H). 13C NMR d: 14.1, 22.6, 24.7, 29.1, 29.3, 31.7, 38.7,
118.2, 124.41, 125.9, 127.3, 129.9, 137.2, 126.6, 206.8. MS (EI):
m/z (%) = 270(M+, 42), 186(43), 171(100), 115(32).
1-(1-Hydroxynaphthalen-2-yl)dodecan-1-one (6c): Pale yellow
solid; m.p. 77–78°C (Lit.28 75–77°C) 1H NMR d: 0.88 (t, 3H,
J = 6.8 Hz), 1.27–1.43 (m, 16H), 1.71–1.81 (m, 2H), 3.05 (t, 2H,
J = 7.6 Hz), 7.26 (d, 1H, J = 7.6 Hz), 7.53 (t, 1H, J = 8.0 Hz), 7.62
(t, 1H, J = 7.6 Hz), 7.68 (d, 1H, J = 8.8 Hz), 7.75 (d, 1H, J = 8.0 Hz),
8.46 (d, 1H, J = 8.0 Hz), 14.17 (s,1H). 13C NMR d: 14.1, 22.7, 24.7,
29.3, 29.4, 29.4, 29.5, 29.6, 31.9, 38.7, 118.2, 124.4, 125.8, 127.3,
129.9, 137.2, 162.6, 206.8. MS (EI): m/z (%) = 326(M+, 35), 308(38),
186(39), 171(100), 115(27).
Experimental
1H NMR and 13C NMR spectra were recorded on a Varian 400 MHz
or Bruker Avance III (500 MHz) instrument in CDCl3 or DMSO-
d6 as the solvent, and chemical shifts were expressed in ppm using
TMS as an internal standard. Mass spectra were measured with a
Trace Finnigan DSQ. High resolution mass spectral (HRMS) analysis
was measured on an Agilent 6210 TOF LC/MS. Melting points were
measured on a Büchi B-540 apparatus and are uncorrected.
1-(1-Hydroxynaphthalen-2-yl)-2-phenylethanone (6d): Pale yellow
1
solid; m.p.97°C (Lit.29 96°C). H NMR d: 4.37 (s, 2H), 7.25–7.38
Typical procedure
In a typical reaction Yb(OTf)3 (0.05 mmol, 5 mol%), 1-naphthol
(1.0 mmol), and butyric acid (1.0 mmol) were added to a flask
flushed with nitrogen, and the mixture was stirred for 6 h at 160°C
in an oil bath. After completion (by TLC) of the reaction, the mixture
was cooled to room temperature. The mixture was then dissolved
in ethyl acetate (20 mL) and washed with H2O (5 mL). The organic
phase was dried with Na2SO4, filtered and evaporated to give a crude
product. The crude product was then charged on a small silica gel
column and eluted with a mixture of ethyl acetate: petroleum ether =
1:10 to afford the corresponding pure product (2-butyryl-1-naphthol)
in high yield (82%).
(m, 6H), 7.52 (t, 1H, J = 7.6 Hz), 7.62 (t, 1H, J = 7.6 Hz), 7.75 (t, 2H,
J = 7.6 Hz), 8.45 (d, 1H, J = 8.4 Hz), 13.98 (s,1H). 13C NMR d: 45.7,
112.9, 118.7, 124.8, 126.3, 127.5, 127.7, 129.1, 129.7, 130.5, 134.6,
137.8, 163.6, 203.9. MS (ESI): m/z = 261.3 (M+-1).
(1-Hydroxynaphthalen-2-yl)(phenyl)methanone (6e): Yellow solid;
m.p.64–65°C (Lit.30 70–72°C). 1H NMR d: 7.22 (d, 1H, J = 8.8 Hz),
7.51–7.62 (m, 5H), 7.66 (t, 1H, J = 8 Hz), 7.72 (d, 2H, J = 8.4 Hz),
7.77 (d, 1H, J = 8.0 Hz), 8.52 (d, 1H, J = 8.0 Hz), 13.96 (s,1H). 13
C
NMR d: 112.9, 118.2, 124.8, 126.3, 127.7, 128.6, 129.4, 130.6, 131.9,
137.6, 138.5, 164.2, 201.7. MS (ESI): m/z = 247.3 (M+-1).
(1-Hydroxynaphthalen-2-yl)(m-tolyl)methanone (6f): Yellow
1
oil H NMR d: 2.45 (s, 3H), 7.23 (t, 1H, J = 8.0 Hz), 7.40 (d, 2H,
Spectra data of products
J = 4.4 Hz), 7.49–7.57 (m, 4H), 7.65 (t, 1H, J = 6.8 Hz), 7.76 (d,
1H, J = 8.0 Hz), 8.52 (d, 1H, J = 8.0 Hz), 13.98 (s,1H). 13C NMR
d: 21.4, 112.6, 117.8, 124.4, 125.2, 125.9, 126.2, 127.4, 128.1, 129.5,
130.3, 132.4, 137.2, 138.2, 138.3, 163.8, 201.7. HRMS(EI): Calcd
for C18H14O2 262.0994 (M+). Found 262.0989.
4-Tolyl butyrate (4a): Pale yellow oil.20 1H NMR d: 1.04 (t, 3H,
J = 7.6 Hz), 1.74–1.83 (m, 2H), 2.34 (s, 3H), 2.52 (t, 2H, J = 7.6 Hz),
6.95 (d, 2H, J = 8.4 Hz), 7.16 (d, 2H, J = 8.4 Hz).
4-Nitrophenyl butyrate (4b): Yellow oil.21 1H NMR d: 1.06 (t, 3H,
J = 7.6 Hz), 1.77–1.83 (m, 2H), 2.59 (t, 2H J = 7.2 Hz), 7.28 (d, 2H,
J = 6.4 Hz), 8.26 (d, 2H J = 6.4 Hz). 13C NMR d: 13.5, 18.2, 36.1,
122.4, 125.1, 145.2, 155.5, 171.0.
1,1'-(4,6-Dihydroxy-1,3-phenylene)bis(2-phenylethanone)
White solid; m.p. 127–128°C. 1H NMR d: 4.17 (s, 4H), 6.42 (s, 1H),
7.21–7.32 (m, 5H), 7.33–7.38 (m, 5H), 8.41 (s, 1H), 12.82 (s, 2H). 13
(8a):
C
4-Nitrophenyl octanoate (4c): Yellow oil.21 1H NMR d: 0.88 (t,
3H, J = 6.4 Hz), 1.26–1.43 (m 8H) 1.73–1.80 (m, 2H), 2.60 (t, 2H,
J = 7.6 Hz), 7.27 (d, 2H, J = 8.8 Hz), 8.26 (d, 2H, J = 8.8 Hz). 13C
NMR d: 14.1, 22.5, 24.6, 28.8, 28.9, 31.5, 34.2, 122.4, 125.1, 145.1,
155.5, 171.2.
NMR d: 39.5, 105.3, 112.7, 127.5, 129.0, 133.9, 136.6, 169.2, 202.0.
HRMS(EI): Calcd for C22H18O4 346.1205 (M+). Found 346.1203.
1,1'-(4,6-Dihydroxy-1,3-phenylene)dibutan-1-one (8b): Yellow oil.31
1H NMR d: 1.05 (t, 6H, J = 7.6 Hz), 1.78–1.86 (m, 4H), 2.95 (t, 4H,
J = 7.2 Hz), 6.43 (s, 1H), 8.28 (s, 1H), 13.06 (s, 2H). 13C NMR d: 13.8,
17.8, 39.7, 104.9, 134.6, 168.7, 204.7. MS (ESI): m/z = 249.3 (M+-1).
1-(2,4-Dihydroxyphenyl)butan-1-one (9b): Pale yellow solid; m.p.
65°C (Lit.32 65–65.5°C). 1H NMR d: 1.01 (t, 3H, J = 7.6 Hz), 1.74–
1.79 (m, 2H), 2.86 (t, 2H, J = 7.2 Hz), 6.38–6.4 (m, 2H), 7.66 (d, 1H,
J = 8.8 Hz), 12.9 (s, 1H). 13C NMR d: 13.8, 18.4, 39.9, 103.5, 107.9,
113.7, 132.4, 162.8, 165.1, 205.5. MS (EI): m/z (%) = 180(M+, 92),
137(100), 136(22).
4-Nitrophenyl benzoate (4d): White solid; m.p. 144–144.5°C
(Lit.22 144–145°C). 1H NMR d: 7.43 (d, 2H, J = 8.8 Hz), 7.55 (t, 2H,
J = 8.0 Hz), 7.67(t, 1H, J = 7.2 Hz), 8.20 (d, 2H, J = 7.2 Hz), 8.34
(d, 2H, J = 8.8 Hz). 13C NMR d: 122.6, 125.3, 128.5, 128.8, 130.3,
134.2, 145.4, 155.7, 164.2.
4-Chlorophenyl octanoate (4e): Yellow oil.23 1H NMR d: 0.89
(t, 3H, J = 6.8 Hz), 1.30–1.41 (m 8H) 1.72–1.77 (m, 2H), 2.54 (t, 2H
J = 7.6 Hz), 7.02 (d, 2H, J = 6.8 Hz), 7.33 (d, 2H J = 6.8 Hz).
4-Chlorophenyl benzoate (4f): Pale yellow solid; m.p. 85–86°C
(Lit.24 86.5–87.7°C). 1H NMR d: 7.17 (d, 2H, J = 8.8 Hz), 7.39 (d,
2H, J = 8.8 Hz), 7.54 (t, 2H, J = 7.2 Hz), 7.67 (t, 1H, J = 7.6 Hz),
8.19 (d, 2H, J = 7.2 Hz).
1,1'-(4,6-Dihydroxy-1,3-phenylene)dioctan-1-one (8c): Yellow
oil.33 1H NMR d: 0.89 (t, 6H, J = 6.8 Hz) 1.25–1.4 (m, 16H), 1.72–
1.77 (m, 4H), 2.94 (t, 4H, J = 7.6 Hz), 6.40 (s, 1H), 8.25 (s, 1H),
13.06 (s, 2H). 13C NMR d: 13.7, 22.3, 24.4, 28.8, 28.9, 31.3, 37.4,
104.7, 112.7, 134.4, 168.5, 204.7. MS (ESI): m/z = 261.5 (M+-1).
1-(2,4-Dihydroxyphenyl)octan-1-one (9c): Yellow solid; m.p. 55–
56°C (Lit.34 55–58°C). 1H NMR d: 0.89 (t, 3H, J = 7.2 Hz) 1.24–1.38
(m, 8H), 1.66–1.76 (m, 2H), 2.89 (t, 2H, J = 7.2 Hz), 5.78 (s, 1H), 6.37–
6.39 (m, 2H), 7.66 (d, 1H, J = 7.2 Hz), 12.85 (s, 1H). 13C NMR d: 14.0,
22.6, 25.1, 29.0, 29.3, 31.6, 38.0, 103.5, 108.1, 132.5, 163.1, 164.9,
205.9. MS (EI): m/z (%) = 236(M+, 24), 180(22), 137(26), 110(100).
1,1'-(4,6-Dihydroxy-5-methyl-1,3-phenylene)bis(2-phenylethanone)
1-(2-Hydroxy-5-methoxyphenyl)heptan-1-one (3g): White solid;
1
m.p. 43–44°C (Lit.25 45°C). H NMR d: 0.89 (t, 3H, J = 6.8 Hz),
1.29–1.40 (m, 8H) 1.41–1.76 (m, 2H), 2.95 (t, 2H, J = 7.2 Hz), 3.08
(s, 3H), 6.93 (d, 1H, J = 8.8 Hz), 7.10 (d, 1H J = 8.8 Hz), 7.21 (s,
1H), 11.98 (s, 1H).
2-Butyryl-1-naphthol (6a): Yellow solid; m.p.83.3°C (Lit.26 85–
86°C). 1H NMR d: 1.06 (t, 3H, J = 7.2 Hz), 1.81–1.86 (m, 2H), 3.03
(t, 2H, J = 7.2 Hz), 7.26 (t, 1H, J = 6.8 Hz), 7.52 (t, 1H, J = 8.0 Hz),
7.62 (t, 1H, J = 8.0 Hz), 7.68 (d, 1H, J = 8.8 Hz), 7.75 (d, 1H, J = 8.0
Hz), 8.46 (d, 1H, J = 8.0 Hz), 14.17 (s,1H). 13C NMR d: 13.9, 18.1,
40.5, 118.2, 124.4, 125.8, 127.3, 129.9, 137.2, 126.5, 206.6. MS (EI):
m/z (%) = 214(M+, 44), 171 (100), 115(32).
1
(8d): White solid; m.p. 141.5–142°C. H NMR d:2.08 (s, 3H), 4.18
(s, 4H), 7.21–7.23 (m, 4H), 7.26–7.37 (m, 6H), 8.33 (s, 1H), 13.12 (s,
2H). 13C NMR d: 7.3, 45.5, 112.3, 114.1, 127.7, 129.32, 129.34, 134.2,
134.5, 167.2, 202.6. HRMS(EI): Calcd for C23H20O4 360.1362 (M+).
Found 360.1368.