JOURNAL OF CHEMICAL RESEARCH 2010 173
3
8
1
p-Amino-polystyrene (4): A suspension of p-nitropolystyrene
5.0 g) in a mixture of acetic acid (20 mL), stannous chloride (5 g),
4-Methoxydiphenylether (3C): Colourless liquid: H NMR (400
(
MHz, CDCl ) δ 3.73 (s, 3H), 6.78–6.82 (m, 2H), 6.85–6.92 (m, 4H),
3
13
concentrated hydrochloric acid (6 mL) was stirred for 72 h at room
temperature to reduce the nitro-compound to the corresponding
6.93–6.98 (m, 1H), 7.16–7.24 (m, 2H); C NMR (100 MHz, CDCl3)
δ 55.8, 115, 117.8, 121, 122.6, 129.7, 150.3, 156.1, 158.7. MS m/z:
200 (M+), 185, 169, 155, 141, 128, 115, 91, 77, 65, 51, 39.
4-Methyldiphenylether (3D): Colourless liquid: H NMR (400
MHz, CDCl ) δ 2.42 (s, 3H), 7.01 (d, J = 8.0 Hz, 2H), 7.05–7.1 (m,
H), 7.12–7.18 (m, 1H), 7.21 (d, J = 8.4 Hz, 2H), 7.38 (t, J = 8.4 Hz,
H); C NMR (100 MHz, CDCl ) δ 20.8, 118.5, 119.3, 122.9, 129.8,
30.4, 133.0, 154.9, 157.9. MS m/z: 184 (M+), 169, 155, 141, 128,
29
aminehydrochloride (3). The residue was washed several times with
hydrochloric acid (12 M) and glacial acetic acid (1:4) mixture and
then with methanol. The product on repeated treatment with dilute
alcoholic NaOH (5%) produced the corresponding free amine. This
was washed with alcohol and dried under reduced pressure.
36
1
3
2
2
1
1
13
3
Polymer-supported Schiff base ligand (5): The suspension of
macroporous aminopolystyrene (2 g) in toluene (50 mL) was taken in
a round bottom flask. Salicylaldehyde (5 mL) was added dropwise to
the stirring suspension of aminopolystyrene. The reaction mixture
was refluxed for 24 h, when the polymer suspension turned into
light yellow in colour. After cooling to room temperature, the light
yellow polymer-anchored Schiff base ligand was filtered off, washed
successively with toluene, methanol and finally dried under reduced
pressure.
Polymer supported copper(II) Schiff base catalyst: The polymer-
anchored Schiff base ligand (2 g) was taken in acetic acid (20mL) in a
round bottom flask. Copper acetate( 50 mg) in acetic acid (5 mL) was
added to the above suspension with constant stirring and the mixture
was then refluxed on an oil bath for 24 h. After cooling the reaction
mixture to room temperature, the separated brownish-yellow colour
polymer complex was filtered off, washed thoroughly with methanol,
and dried under reduced pressure.
15, 91, 77, 65, 51, 41.
4
39
-Cyano-4-methoxydiphenylether (3E): White solid, m.p. 108–
39 1
1
6
(
1
10 °C (lit. 109 °C): H NMR (400 MHz, CDCl ) δ 3.75 (s, 3 H),
3
13
.84–6.89 (m, 4H), 6.91–6.95 (m, 2H), δ 7.47–7.51 (m, 2H); C NMR
100 MHz, CDCl ) δ 55.8, 105.4, 115.4, 117.3, 119.1, 122, 134.2,
48, 157.2, 162.6
-Acetyldiphenylether (3F): White solid, m.p. 47 °C (lit. 49–51
3
37
37
4
1
°
2
C): H NMR (400 MHz, CDCl ) δ 7.94(d, J = 10.4Hz, 2H), 7.39(m,
3
H), 7.20(t, J = 7.2Hz, S10 1H), 7.07(d, J = 7.8Hz, 2H), 7.00(d,
13
J = 9.0Hz, 2H), 2.57(s, 3H). C NMR (100MHz, CDCl ): δ 196.7,
3
1
2
61.9, 155.5, 131.9, 130.6, 130.0, 124.6, 120.2, 117.3, 26.4. MS m/z:
12(M+), 197, 141, 115, 99, 77, 63, 51, 43, 39.
-Phenoxybenzonitrile (3G): Oil: H NMR (400 MHz, CDCl ):
δ 7.55(d, J = 8.6 Hz, 2H), 7.43(t, J = 7.9 Hz, 2H), 7,20 (t, J = 7.6
Hz, 1H), 7.00 (d, J = 7.9 Hz, 2H), 6.95 (d, J = 8.8 Hz, 2H). C
NMR (100MHz, CDCl ) δ 160.8, 151.6, 136.8, 131.5, 123.0, 119.4,
40
1
4
3
13
3
1
16.5, 120.3, 102.6.
-Methyl-4p-chlorodiphenylether (3H): White solid, m.p. 46.3 °C
Due to the insolubility of the polymer-anchored Cu(II) Schiff base
catalyst in all common organic solvents, its structural investigation
was limited to physicochemical properties, chemical analysis,
SEM, IR, TGA-DTA and UV-Vis spectroscopic data only. Chemical
analysis results suggested 1.68 wt % Cu in the copper catalyst.
The morphological change in the polymer-anchored Schiff base ligand
and immobilised copper(II) complex is quite evident from the SEM
images, suggesting the loading of copper metal on the surface of the
polymer matrix. Thermogravimetric study suggests that the polymer
anchored Cu(II) complex is stable up to 250 °C and degrades at a
15
4
15
1
(
2
lit. 47.5–49 °C): H NMR (400 MHz, CDCl ) δ 7.20 (d, J = 8.6 Hz,
3
13
H), 7.14 (d, J = 8.4 Hz, 2H), 6.85–6.94 (m, 4H), 2.30 (s,3H). C
NMR (100MHz, CDCl ) δ 155.1, 153.8, 130.9, 129.3, 128.4, 127.4,
18.4, 120.2, 20.5. MS m/z: 220, 218 (M+), 169, 155, 141, 128, 115,
3
1
9
1, 77, 51, 41, 39.
4
37
1
-Chlorodiphenylether (3I): Colourless liquid: H NMR (400
MHz, CDCl ) δ 6.82–6.87 (m, 2H), 6.89–6.93 (m, 2H), 7.01–7.06 (m,
H), 7.15–7.21 (m, 2H), 7.22–7.28 (m, 2H); C NMR (100 MHz,
CDCl ) δ 119.1, 120.2, 123.8, 128.3, 129.8, 130, 156.1, 157. MS m/z:
06, 204 (M+), 169, 141, 115, 77, 51, 39.
-Methyldiphenylether (3J): Colourless liquid: H NMR (400
MHz, CDCl ) δ 2.23 (s, 3H), 6.87–6.92 (m, 3H), 6.98–7.08 (m, 2H),
7.12–7.18 (m, 1H), 7.22–7.31 (m, 3H); CNMR (100 MHz, CDCl3)
δ 16.3, 117.4, 119.9, 122.4, 124.1, 127.3, 129.8, 130.1, 131.6,154.6,
158.1. MS m/z: 184(M+), 165, 141, 106, 91, 78, 65, 51, 39.
4-Methyl-3-methoxydiphenylether (3K): Colourless liquid: H
NMR (400 MHz, CDCl ) δ 2.33 (s, 3H), 3.76 (s, 3H), 6.53–6.56 (m,
2H), 6.61 (d, J = 8.4 Hz,1H), 6.90–6.95 (m, 2H), 7.13 (d, J = 7.6 Hz,
2H ), 7.19 (t, J = 8.4 Hz, 1H); C NMR(100 MHz, CDCl3) δ 20.8,
55.4, 104.5, 108.6, 110.6, 119.4, 130.1, 130.3, 133.2, 154.6,159.2,
161. MS m/z: 214 (M+), 199, 171, 143, 128, 91, 77, 65, 51, 41.
4-Methyl-4p-methoxydiphenylether (3L): White solid, m.p. 48–
50 °C (lit. 49–50 °C): H NMR (400 MHz, CDCl ) δ 2.35 (s, 3H),
3
13
1
3
−
1
considerably higher temperature. The peaks at 1630 cm and 1310
2
−
1
30
−1
cm due to monodentate acetate group, 1605 cm due to vC=N of
36
1
2
−1
31
32
azomethine group, a weak peak at 628 cm (vCu-O) and a vCu-N
3
−
1
13
stretching vibration at 530 cm are present in the spectra of the com-
plex. There is also a weak band in the 3435 cm− region, indicating the
presence of an OH group. The copper(II) complex shows a character-
istic frequency vCu-Oacetate oxygen around 430 cm . The UV-spectrum
exhibits a band at ca 270 nm due to intra-ligand charge transfer and
bands at 350 and 450 nm arise due to ligand to metal charge transfer.
The band at 450 nm indicates the phenolic oxygen to copper charge
1
−
1 30
41
1
3
13
33–34
transfer.
The expected d–d bands are not observed in the polymer-
anchored copper catalyst. Possibly poor loading of the metal on the
polymer matrix has prevented the exhibit of the d–d band, which is a
42
35
6
1
low-energy and less-intense band.
3
3
.82 (s, 3H), 6.90 (d, J = 8.9 Hz, 4H), 7.0 (d, J = 8.8 Hz, 2H), 7.13
13
General procedure for O-arylation phenols with aryl halides
Under a nitrogen atmosphere, a 100 mL round bottomed flask was
charged with the polymer- supported copper(II) catalyst (0.05 g), aryl
(d, J = 8.3 Hz, 2H ), C NMR (100 MHz, CDCl ) δ 20.7, 55.7, 114.9,
3
117.9, 120.4, 130.2, 132.1, 150.9 , 155.8, 156.2. MS m/z: 214 (M+),
199, 171, 143, 128, 91, 77, 65, 39.
t
halide (1.0 mmol), phenol (1.0 mmol), Cs CO (1.0 mmol), Bu NBr
2
3
4
(
0.1 mmol), dihexyl ether (0.425 mmol) and NMP (10 mL). The reac-
We thank the Department of Chemistry, University of Calcutta,
for providing instrumental support. We gratefully acknowl-
edge DST, New Delhi, for the award of a grant under its
FIST program to the Department of Chemistry, University
of Kalyani. SMI acknowledge the following agencies for
funding: DST, CSIR and UGC, New Delhi, India.
tion mixture was refluxed at 120 °C for 12 h. To study the progress of
the reaction, samples of the reaction mixtures were collected at differ-
ent time intervals and quantified by GC analysis using dihexyl ether as
internal standard. After cooling to room temperature, the reaction
mixture was extracted with ethyl acetate (3 × 20 mL) and the com-
bined organic layers were dried with anhydrous Na SO . The filtrate
2
4
was concentrated under reduced pressure and the resulting residue
was purified by column chromatography on silica gel to provide the
desired product.
Received 17 December 2009; accepted 5 March 2010
Paper 090919 doi: 10.3184/030823410X12680707465896
Published online: 23 March 2010
36
1
Diphenylether (3A): Colourless liquid: H NMR (400 MHz,
CDCl ) δ 7.09–7.15 (m, 4H), 7.16–7.22(m, 2H); 7.39–7.46 (m, 4H);
3
13
C NMR (100 MHz, CDCl ) δ 119, 123.4, 129.9, 157.4. MS m/z:
3
References
1
70(M+), 141, 77, 65, 51, 39.
37
37
1
2
3
M. Wolter, G. Nordman, G.E. Job and S.L. Buchwald, Org. Lett., 2002, 4,
73.
N. Yamazaki, I. Washio, Y. Shibasaki and U.M. Mitsuru, Org. Lett., 2006,
, 2321.
4
-Nitrodiphenylether (3B): Yellow solid, m.p. 57–60 °C (lit.
9
1
6
0 °C): H NMR (400 MHz, CDCl ) δ 6.99–7.02 (m, 2H), 7.05–7.10
3
(
m, 2H), 7.22–7.29 (m, 1H), 7.40–7.44 (m, 2H), 8.16–8.21 (m, 2H);
8
1
3
C NMR (100 MHz, CDCl ) δ 117.2, 120.6, 125.5, 126, 130.4, 142.7,
R.K. Gujadhur, C.G. Bates and D. Venkataraman, Org. Lett., 2001, 3,
3
1
54.8, 163.4. MS m/z: 215 (M+), 185, 141, 129, 115, 77, 63, 51.
4135.