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H. Wang et al. / Dyes and Pigments 86 (2010) 238e248
2.8. 9,90-Dihexyl-3,30-bicarbazole-6,60-dicarbaldehyde (13)
(d, J ¼ 8.4 Hz, 1H), 7.24 (t, J ¼ 8.4 Hz, 1H), 4.29 (t, J ¼ 6.9 Hz, 2H),
1.84e1.87 (m, 2H), 1.37e1.41 (m, 2H), 0.94 (t, J ¼ 7.2 Hz, 3H) ppm.
HRMS Mþ: Calcd for C17H16INO: 377.0277, Found: 377.0278.
This compound was prepared according to the general proce-
dure for 8 by using 12 (5.00 g, 10 mmol), phosphorus oxychloride
(2.8 mL, 30 mmol), and DMF (3.0 mL, 40 mmol). The mixture was
purified by flash chromatography on silica gel (ethyl acetate/
petroleum ether, 1/4, v/v) to afford 13 (3.80 g, 68%). m.p.
2.12. 9,90-Dibutyl-3,30-bicarbazole-6-carbaldehyde (15)
Under a nitrogen atmosphere, a mixture of compound 14
(1.0 mmol), Pd(PPh3)4 catalyst (0.04 mmol) and the carbazole
boronic acid 11 (1.0 mmol) was stirred in dry toluene (15 mL). Then,
2 mol Lꢀ1 K2CO3 (aq) solution (2 mL) was added via syringe. The
reaction mixture was heated to reflux for 36 h. After cooling, the
product was extracted with dichloromethane, washed with water,
dried over MgSO4, filtered, concentrated and further purified by
silica gel column chromatography (ethyl acetate/petroleum ether,
1/10, v/v). The pure compound 15 was obtained (0.31 g, 64%). m.p.
138e139 ꢁC, yellow powder, 1HNMR (300 MHz, CDCl3):
d
¼ 10.11 (s,
2H), 8.89 (s, 2H), 8.47 (s, 2H), 8.05 (d, J ¼ 6.3 Hz, 2H), 7.91 (d,
J ¼ 6.3 Hz, 2H), 7.57 (d, J ¼ 6.3 Hz, 2H), 7.51 (d, J ¼ 6.3 Hz, 2H), 4.37
(t, J ¼ 5.4 Hz, 2H), 1.89e1.97 (m, 4H), 1.28e1.45 (m, 12H), 0.88 (t,
J ¼ 5.1 Hz, 6H) ppm. HRMS Mþ: Calcd for C38H40N2O2: 556.3090,
Found: 556.3089.
2.9. 3-Bromo-9-butylcarbazole (10)
88e90 ꢁC, yellow powder, 1H NMR (300 MHz, CDCl3):
d
¼ 10.12 (s,
In a flask, covered with aluminum foil, a stirred solution of
9-butylcarbazole 7a (4.46 g, 20.0 mmol) in CHCl3 (100 mL) was
cooled to 0 ꢁC. NBS (3.56 g, 20.0 mmol) was added in small
portions. The mixture was allowed to warm to room temperature
overnight. CHCl3 was evaporated and the crude product was puri-
fied by extraction with diethylether and water. After same work up
as above, final product was obtained as colorless oil (4.23 g, 70%). 1H
1H), 8.70 (s,1H), 8.48 (s,1H), 8.41 (s,1H),8.21 (d, J ¼ 7.8 Hz,1H), 8.05
(d, J ¼ 8.7 Hz, 1H), 7.92 (d, J ¼ 8.4 Hz, 1H), 7.84 (d, J ¼ 8.7 Hz, 1H),
7.46e7.56 (m, 5H), 7.29 (s, 1H), 4.34e4.41 (m, 4H), 1.90e1.94 (m,
4H), 1.44e1.49 (m, 4H), 0.96e1.01 (m, 6H) ppm. HRMS Mþ: Calcd
for C33H32N2O: 472.2515, Found: 472.2514.
2.13. General procedure for the synthesis of the compounds
NMR (400 MHz, CDCl3):
d
¼ 8.19 (s, 1H), 8.02 (d, J ¼ 7.2 Hz, 1H),
(16e19)
7.36e7.53 (m, 3H), 7.23e7.26 (m, 2H), 4.23 (t, J ¼ 6.8 Hz, 2H),
1.77e1.87 (m, 2H), 1.28e1.39 (m, 2H), 0.86 (t, J ¼ 7.2 Hz, 3H) ppm.
HRMS Mþ: Calcd for C16H16BrN: 301.0466, Found: 301.0464.
A mixture of the corresponding aromatic aldehyde (1.0 mmol),
2-aminothiophenol (1.25 mmol, 1.25 equiv), and DMSO (30 mL)
was heated in an oil bath to a bath temperature of 195 ꢁC, held at
that temperature for 2 h, and then poured into water. The separated
solids were collected, reslurried in 1:4 acetic acidewater (50 mL),
filtered, and washed with water and dilute sodium bicarbonate
solution. These solids were recrystallized from ethanol to give
compounds 16e19.
2.10. 9-Butylcarbazol-3-ylboronic acid (11)
A solution of 3-bromo-9-butylcarbazole 10 (3.03 g, 10.0 mmol)
in anhydrous THF (50 mL) was cooled to ꢀ78 ꢁC. n-BuLi (2.5 mol
Lꢀ1 in hexane, 4.8 mL, 12.0 mmol) was slowly added dropwise.
After complete addition, the reaction mixture was stirred for
another 1 h. Then, triisopropyl borate (3.5 mL, 15.0 mmol) was
added at once. The mixture was allowed to warm to room
temperature for 15 h. The reaction was finally quenched with HCl
(2.0 mol Lꢀ1, 40 mL) and the mixture was poured into a large
amount of water. After extraction with CH2Cl2 (3 ꢂ 20 mL), the
organic layer was washed with brine, dried over MgSO4, concen-
trated. Further purification by silica gel column chromatography
(petroleum ether/dichloromethane, 2/1, v/v) afforded 11 as a white
solid (1.44 g, 54%). m.p. 148e150 ꢁC, 1H NMR (300 MHz, DMSO-d6):
3-Benzothiazolyl-9-butyl-carbazole (16): yield 82%, m.p. 121 ꢁC,
yellow powder, 1H NMR (300 MHz, CDCl3):
d
¼ 8.85 (s, 1H),
8.18e8.21 (m, 2H), 8.06 (d, J ¼ 8.1 Hz, 1H), 7.89 (d, J ¼ 7.5 Hz, 1H),
7.42e7.51 (m, 4H), 7.25e7.37 (m, 2H), 4.33 (t, J ¼ 6.9 Hz, 2H),
1.86e1.90 (m, 2H), 1.41e1.43 (m, 2H), 0.96 (t, J ¼ 7.2 Hz, 3H) ppm.
13C NMR (75 MHz, CDCl3):
126.4, 125.7, 124.8, 123.5, 123.1, 122.8, 121.7, 121.1, 120.2, 119.9, 109.4,
109.2, 43.2, 31.3, 20.8, 14.1 ppm. HRMS Mþ: Calcd for C23H20N2S:
356.1347, Found: 356.1346.
d
¼ 169.7, 154.6, 142.3, 141.3, 135.1, 126.6,
9-Butyl-3,6-di-2-benzothiazolyl-carbazole (17): yield 80%, m.p.
d
¼ 8.59 (s, 1H), 8.11 (d, J ¼ 7.5 Hz, 1H), 7.93 (s, 2H), 7.89 (s, 1H),
189 ꢁC, yellow powder, 1H NMR (300 MHz, CDCl3):
8.26 (d, J ¼ 7.8 Hz, 2H), 8.09 (d, J ¼ 7.8 Hz, 2H), 7.93 (d, J ¼ 6.6 Hz,
2H), 7.50e7.52 (m, 4H), 7.38e7.41 (m, 2H), 4.38 (s, 2H), 1.90e1.94
(m, 2H), 1.41e1.47 (m, 2H), 0.98 (s, 3H) ppm. 13C NMR (75 MHz,
d
¼ 8.93 (s, 2H),
7.52e7.59 (m, 2H), 7.43 (t, J ¼ 7.5 Hz, 1H), 7.20 (t, J ¼ 7.5 Hz, 1H),
4.38 (t, J ¼ 6.6 Hz, 2H), 1.71e1.76 (m, 2H), 1.25e1.32 (m, 2H), 0.87 (t,
J ¼ 7.5 Hz, 3H) ppm. HRMS Mþ: Calcd for C16H18BNO2: 267.1431,
Found: 267.1430.
CDCl3):
d
¼ 169.2, 154.5, 142.8, 135.2, 126.5, 126.2, 125.7, 124.9,
123.5,122.9,121.8,120.6,109.7, 43.5, 31.3, 20.7,14.1 ppm. HRMS Mþ:
Calcd for C30H23N3S2: 489.1333, Found: 489.1331.
2.11. 9-Butyl-6-iodo-carbazole-3-carbaldehyde (14)
6-(2-Benzothiazolyl)-9,90-dibutyl-3,30-bicarbazole (18): yield
Under heavy stirring and slightly warming, 5.02 g (20 mmol) of
8 was dissolved in 20 mL of glacial acetic acid. Then, 6.64 g
(40 mmol) of KI and 12.84 g (60 mmol) of KIO3 were added, and the
reaction mixture was stirred for 3 h at 70 ꢁC. After cooling, the salts
were filtered off and washed thoroughly with water (50 mL) and
dichloromethane (100 mL). The aqueous phase was extracted
several times with dichloromethane. The combined organic phases
were washed with a diluted ammonia solution until pH z 8, with
a NaHSO3 solution, and with brine and dried over MgSO4. After
removal of the solvents, the crude compound was stirred for 15 min
in 50 mL of boiling ethanol; the solution was cooled, and the pure
product was isolated by filtration (5.65 g, 75%). m.p. 115e116 ꢁC,
75%, m.p. 202 ꢁC, yellow powder, 1H NMR (300 MHz, CDCl3):
d
¼ 8.89e9.01 (m, 2H), 8.54 (s, 1H), 8.44 (s, 1H), 8.08e8.23 (m, 3H),
7.83e7.93 (m, 3H), 7.37e7.54 (m, 7H), 4.37e4.39 (m, 4H), 1.91e1.92
(m, 4H), 1.43e1.47 (m, 4H), 0.96e0.99 (m, 6H) ppm. 13C NMR
(75 MHz, CDCl3):
d
¼ 169.6, 154.6, 154.6, 148.1, 142.7, 140.5, 140.3,
140.2, 140.2, 135.1, 134.4, 133.1, 132.8, 128.7, 123.4, 123.4, 126.3,
125.6, 124.8, 124.7, 123.7, 123.6, 122.8, 121.7, 120.7, 119.4, 109.5,
109.2, 109.1, 43.3, 43.2, 31.5, 31.4, 20.8, 20.7, 14.1, 14.0 ppm. HRMS
Mþ: Calcd for C39H35N3S: 577.2552, Found: 577.2564.
6,60-(Di-2-benzothiazolyl)-9,90-dihexyl-3,30-bicarbazole (19):
yield 78%, m.p. 249 ꢁC, yellow powder, 1H NMR (300 MHz, CDCl3):
d
¼ 8.97 (s, 2H), 8.57 (s, 2H), 8.23 (d, J ¼ 8.7 Hz, 2H), 8.09 (d,
yellow powder, 1H NMR (300 MHz, CDCl3):
1H), 8.44 (s, 1H), 8.03 (d, J ¼ 8.7 Hz, 1H), 7.78 (d, J ¼ 8.4 Hz, 2H), 7.47
d
¼ 10.07 (s, 1H), 8.51 (s,
J ¼ 8.1 Hz, 2H), 7.91 (d, J ¼ 7.8 Hz, 4H), 7.47e7.57 (m, 6H), 7.37 (t,
J ¼ 7.5 Hz, 2H), 4.39 (t, J ¼ 6.6 Hz, 4H), 1.94e1.98 (m, 4H), 1.34e1.46