The crude product was recrystallized from ethanol–water (351)
to give 5-(2,4-dihydroxyphenyl)tetrazole as colorless crystals
(85% yield). Mp 304 °C; IR (KBr): 3348, 1612, 1490 cm−1;
Anal. Calc. for C H N O : C, 47.19; H, 3.37; N, 31.46. Found:
temperature. The pyridine was then removed by evaporation
in vacuo, and the resulting residue was added to a hot ethanolic
solution of FeCl Ω6H O. The mixture was then allowed to
cool and filtered. The solid was collected and recrystallized
from ethanol (82% yield). Mp 97 °C; IR (KBr): 3400, 2919,
3
2
7
6 4 2
C, 47.20; H, 3.20; N, 31.92.
1632 cm−1. 1H NMR (200 MHz, CDCl ): 12.71 (s, 1H),
3
7.96–6.52 (m, 7H), 4.02 (t, J=6.4 Hz, 2H), 1.82 (t, J=6.75 Hz,
General procedure for preparation of 5-(2-hydroxy-4-alkoxy-
phenyl)-2-alkyltetrazoles 5. To
2H), 1.30 (m, 14H), 0.90 (t, 3H) ppm. 13C NMR (50 MHz,
CDCl ): 169.28, 163.03, 159.87, 151.87, 131.87, 129.51, 126.44,
a suspension of 5-(2,4-
dihydroxyphenyl)tetrazole (0.03 mol) and anhydrous potass-
ium carbonate (0.06 mol), in cyclohexanone (50 ml), was added
the appropriate alkyl halide (0.065 mol). The reaction mixture
was stirred for 72 h at 150 °C. The mixture was then allowed
to cool and filtered. The filtrate was poured into ice cold water
(100 ml) and the residue formed was recrystallized from
ethanol.
3
124.89, 121.58, 121.32, 110.15, 108.05, 101.77, 68.23,
31.82–14.04 ppm. Anal. Calc. for C H NO S: C, 71.96; H,
7.56; N, 3.65. Found: C, 71.66; H, 7.55; N, 4.00.
23 29
2
Bis[2-(2-hydroxy-4-decyloxyphenyl)benzothiazole]
copper(II) 11. An ethanolic solution (10 ml) of 2-(2-hydroxy-4-
decyloxyphenyl)benzothiazole (2 mmol) was added to a hot
ethanolic solution (10 ml) of copper() acetate (1 mmol). The
solution was refluxed for 20 min and then cooled. The precipi-
tate was collected by filtration and recrystallized from cyclohex-
ane–ethanol (153) (68% yield). The brown copper complex
was characterized by IR spectroscopy and elemental analysis.
The 1H NMR spectrum of the complex exhibits large shifts
relative to the free ligand, and all signals are broadened as a
result of the paramagnetic metallic ion. Mp 216 °C; IR (KBr):
2922, 1608, 1468 cm−1. Anal. Calc. for C H N O S Cu: C,
homologue
melting point/°C
yield (%)
C H
10 21
C H
12 25
C H
14 29
40–42
50–52
60–62
66
70
70
For the homologue C H : IR (KBr): 3314, 2954, 1634,
1472 cm−1. 1H NMR (200 MHz, CDCl ): 9.81 (s, 1H),
2H), 2.05 (q, 2H), 1.79 (q, 2H), 1.44–1.19 (m, 44H), 0.87 (t,
14 29
3
7.90–6.57 (m, 3H), 4.64 (t, J=7.1 Hz, 2H), 3.98 (t, J=6.5 Hz,
46 56
2 4 2
66.71; H, 6.76; N, 3.38. Found: C, 66.76; H, 6.67; N, 3.48.
6H) ppm. 13C NMR (50 MHz, CDCl ): 164.18, 162.50, 158.01,
128.31, 108.16, 104.18, 102.11, 68.21, 58.30, 31.95–14.15 ppm.
3
Bis[2-(2-hydroxy-4-decyloxyphenyl)benzothiazole]oxo-
vanadium(IV ) 12. An ethanolic solution (10 ml) of 2-(2-
hydroxy-4-decyloxyphenyl)benzothiazole (2 mmol) was added
to a hot ethanolic solution (10 ml) of vanadyl sulfate pentahy-
drate (1 mmol). The solution was refluxed for 20 min and then
cooled. The precipitate was collected by filtration and recrys-
tallized from cyclohexane–ethanol (153) (65% yield). The
green oxovanadium complex was characterized by IR spec-
troscopy and elemental analysis. The 1H NMR spectrum of
the complex exhibits large shifts relative to the free ligand, and
all signals are broadened as a result of the paramagnetic
metallic ion. Mp 194 °C; IR (KBr): 2920, 1605, 1469, 976 cm−1.
Anal. Calc. for C H N O S V: C, 66.44; H, 6.73; N, 3.37.
Anal. Calc. for C H N O : C, 73.56; H, 10.86; N, 9.80. Found:
C, 73.58; H, 11.05; N, 9.52.
35 62
4 2
General procedure for preparation of bis[5-(2-hydroxy-4-
alkoxyphenyl)-2-alkyltetrazole]copper(II ) 6. An ethanolic solu-
tion (10 ml) of the appropriate tetrazole (2 mmol) was added
to a hot ethanolic solution (10 ml) of copper() acetate
(1 mmol). The solution was refluxed for 20 min and then
cooled. The precipitate was collected by filtration and recrys-
tallized from chloroform–ethanol (153). The green copper
complexes were characterized by IR spectroscopy and elemen-
tal analysis. The 1H NMR spectra of the complexes exhibit
large shifts relative to the free ligands, and all signals are
broadened as a result of the paramagnetic metallic ion.
46 56
2 5 2
Found: C, 66.43; H, 6.58; N, 3.44.
The authors gratefully acknowledge the financial support of
CNPq, CAPES and PRONEX.
homologue
yield (%)
C H
10 21
C H
12 25
C H
14 29
62
65
60
References
1
2
A. M. Giroud-Godquin and P. M. Maitlis, Angew. Chem., Int. Ed.
Engl. 1991, 30, 375.
P. Espinet, M. A. Estruelas, L. A. Oro and J. L. Serrano, Coord.
Chem. Rev., 1992, 117, 215.
For the homologue C H : IR (KBr): 2956, 1610, 1466 cm−1.
14 29
3
4
S. A. Hudson and P. M. Maitlis, Chem. Rev., 1993, 93, 861.
M. J. Baena, J. Barbera´, P. Espinet, A. Ezcurra, M. B. Ros and J. L.
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C, 1997, 51, 2430.
Anal. Calc. for C H N O Cu: C, 69.80; H, 10.14; N, 9.31.
Found: C, 69.66; H, 10.18; N, 9.55.
70 122
8 4
5
6
7
8
9
2-Hydroxy-4-decyloxybenzaldehyde 7. To a suspension of
2,4-dihydroxybenzaldehyde (0.03 mol) and anhydrous potass-
ium carbonate (0.03 mol) in acetone (50 ml) was added 1-
bromodecane (0.035 mol). The reaction mixture was refluxed
for 56 h. The mixture was then allowed to cool and filtered.
The solvent was removed and the residue was distilled at
reduced pressure giving the product as a clear liquid (63%
yield): bp 185 °C (0.5 mm); IR (thin film): 3300, 2920,
1650 cm−1.
10 D. Demus and H. Zaschke, Flu´ssige Kristalle in Tabellen II,
Springer Verlag, Leipzig, 1984.
11 H. Sackmann and D. Demus, Mol. Cryst. L iq. Cryst., 1966, 2, 81.
12 G. W. Gray and J. W. Goodby, Smectic L iquid Crystals: T extures
and Structure, Heyden and Son Inc., 1984, pp. 47–48.
2-(2-Hydroxy-4-decyloxyphenyl)benzothiazole
10.
2-
Hydroxy-4-decyloxybenzaldehyde (0.02 mol) was dissolved in
10 ml of dry pyridine containing 2-aminothiophenol (0.02 mol)
under an atmosphere of nitrogen and was stirred 5 h at room
Paper 8/01159A; Received 9th February, 1998
1354
J. Mater. Chem., 1998, 8(6), 1351–1354