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M. Mao et al. / Dyes and Pigments 94 (2012) 224e232
2.2.1.3. 2-(4-Bromophenyl)-6,9-dimethoxy-1H-phenanthro[9,10-d]
3.99 (s, 3 H, OCH3), 1.83 (m, 2 H, CH2), 1.11 (m, 10 H, CH2), 0.82 (t,
imidazole (1c). White solid, yield: 96%. Rf ¼ 0.60 (CH2Cl2). 1H NMR
J ¼ 6.9 Hz, 3 H, CH3). 13C NMR (75 MHz, CDCl3):
d 157.6, 156.6, 150.4,
(300 MHz, DMSO [D6]):
d
13.35 (s, 1 H, NH), 8.45 (d, J ¼ 8.1 Hz, 2 H,
136.7, 131.9, 131.5, 130.3, 130.1, 128.9, 125.2, 124.1, 123.7, 122.1, 118.0,
116.2, 115.6, 107.1, 105.9, 55.6, 55.5, 46.7, 31.7, 30.1, 29.1, 28.9, 26.2,
22.6, 14.1. IR (KBr, cmꢀ1): 2929 (s), 1620 (m), 1588 (m), 1465 (s),
1365 (m), 1230 (s), 1049 (m), 823 (m). TOFMS (EI) calcd for (Mþ)
C31H33BrN2O2: 544.1725, found: 544.1718.
ArH), 8.23e8.20 (m, 4 H, ArH), 7.80 (d, J ¼ 8.4 Hz, 2 H, ArH), 7.41 (m,
2 H, ArH), 4.02 (s, 6 H, OCH3). 13C NMR (75 MHz, DMSO [D6]):
d
157.6, 147.4, 132.3, 130.2, 129.2, 128.2, 123.9, 122.5, 116.9, 107.1,
56.0. IR (KBr, cmꢀ1): 1623 (m), 1597 (m), 1470 (s), 1434 (m), 1406
(m), 1222 (s), 1172 (s), 1032 (s), 822 (m). TOFMS (EI) calcd for (Mþ)
C23H17BrN2O2: 432.0473, found: 432.0485.
2.2.2.4. 6,9-Dimethoxy-1-octyl-2-thiophen-2-yl-1H-phenanthro
[9,10-d]imidazole (2d). white solid, yield: 84%. Rf ¼ 0.30 (CH2Cl2/
2.2.1.4. 6,9-Dimethoxy-2-thiophen-2-yl-1H-phenanthro[9,10-d]imi-
petroleum ether 2:1). 1H NMR (300 MHz, CDCl3):
d 8.68 (d,
dazole (1d). White solid, yield: 90%. Rf ¼ 0.50 (CH2Cl2). 1H NMR
J ¼ 8.8 Hz, 1 H, ArH), 8.10e8.08 (m, 2 H, ArH), 7.95 (s, 1 H, ArH), 7.51
(dd, J ¼ 5.1 Hz, 0.9 Hz, 1 H, ArH), 7.48 (d, J ¼ 3.6 Hz, 1 H, ArH), 7.33
(dd, J ¼ 8.8 Hz, 2.4 Hz, 1 H, ArH), 7.28e7.25 (m, 1 H, ArH), 7.20 (dd,
J ¼ 5.0 Hz, 3.6 Hz, 1 H, ArH), 4.60 (t, J ¼ 7.8 Hz, 2 H, CH2), 4.01 (s, 3 H,
OCH3), 4.00 (s, 3 H, OCH3), 2.01e1.95 (m, 2 H, CH2), 1.45e1.35 (m,
10 H, CH2), 0.87 (t, J ¼ 6.6 Hz, 3 H, CH3). 13C NMR (75 MHz, CDCl3):
(300 MHz, DMSO [D6]):
d
13.33 (s, 1 H, NH), 8.38 (d, J ¼ 9.0 Hz, 2 H,
ArH), 8.22 (s, 2 H, ArH), 7.86 (dd, J ¼ 3.6 Hz, 1.2 Hz, 1 H, ArH), 7.68
(dd, J ¼ 5.0 Hz, 1.1 Hz, 1 H, ArH), 7.40 (m, 2 H, ArH), 7.26 (dd,
J ¼ 5.0 Hz, 3.7 Hz, 1 H, ArH), 4.03 (s, 6 H, OCH3). 13C NMR (75 MHz,
DMSO [D6]):
d 157.0, 143.9, 134.2, 128.7, 128.1, 127.2, 125.2, 123.3,
116.4, 106.6, 55.5. IR (KBr, cmꢀ1): 1624 (m), 1579 (m), 1466 (s), 1408
(m), 1232 (s), 1203 (s), 1174 (s), 1031 (m), 834 (m). TOFMS (EI) calcd
for (Mþ) C21H16N2O2S: 360.0932, found: 360.0887.
d 157.6, 156.6, 144.8, 136.5, 132.4, 130.3, 128.9, 128.1, 127.8, 127.6,
125.5, 124.3, 121.9, 121.8, 117.8, 116.2, 115.5, 107.2, 105.8, 55.5, 55.4,
46.6, 31.7, 30.3, 29.1, 29.0, 26.4, 22.6, 14.1. IR (KBr, cmꢀ1): 2923 (s),
1617 (m), 1579 (m), 1479 (s), 1366 (m), 1235 (s), 841 (m). TOFMS (EI)
calcd for (Mþ) C29H32N2O2S: 472.2185, found: 472.2167.
2.2.2. General procedure for the synthesis of 2aed
1H-phenanthro[9,10-d]imidazole derivative (2.0 mmol) and
NaOH (8.0 mmol) were added into DMSO (5 mL). The mixture was
stirred at room temperature for 2 h. After addition of n-octyl
bromide (3.0 mmol), the reaction was stirred at room temperature
for another 25 min. The temperature was increased to 85 ꢁC, and
the reaction mixture was stirred at this temperature overnight. The
mixture was diluted with water, extracted with CH2Cl2. The
combined organic solution was dried (MgSO4), and concentrated in
vacuo. The residue was further purified by trituration with petro-
leum ether to give a solid.
2.2.3. General procedure for the preparation of 3aed
1-Alkyl-1H-phenanthro[9,10-d]imidazole derivative (4.0 mmol)
was dissolved in anhydrous THF (12 mL) under N2 and cooled
to ꢀ78 ꢁC. n-BuLi (4.8 mmol) was added. The mixture was stirred at
this temperature for 1 h, then (CH3O)3B (12.0 mmol) was added and
the mixture was left to stand for 16 h. HCl (20%, 10 mL) was added,
and stirring was continued for 0.5 h. The solid was obtained by slow
diffusion of water into the THF solution at room temperature. The
precipitate was collected by filtration and washed with water
(3 ꢂ 100 mL) and light petroleum (20 mL), respectively. The product
was further dried under reduced vacuum for 2 h and the solid is
pure enough for the next reaction.
2.2.2.1. 2-(4-Bromophenyl)-1-octyl-1H-phenanthro[9,10-d]imidazole
(2a). White solid, yield: 90%. Rf ¼ 0.50 (CH2Cl2/petroleum ether
2:1). 1H NMR (300 MHz, CDCl3):
d
8.85 (d, J ¼ 7.8 Hz, 1 H, ArH), 8.77
(d, J ¼ 7.8 Hz, 1 H, ArH), 8.71 (d, J ¼ 8.1 Hz, 1 H, ArH), 8.26 (d,
J ¼ 7.8 Hz, 1 H, ArH), 7.73e7.61 (m, 8 H, ArH), 4.59 (t, J ¼ 7.5 Hz, 2 H,
CH2), 1.94e1.87 (m, 2 H, CH2), 1.24e1.78 (m, 10 H, CH2), 0.85 (t,
2.2.3.1. 4-(1-Octyl-1H-phenanthro[9,10-d]imidazol-2-yl)-phenyl-
boronic acid (3a). White solid, yield: 90%. Rf ¼ 0.70 (CH2Cl2/CH3OH
10:1). 1H NMR (300 MHz, DMSO [D6]):
d
9.07 (d, J ¼ 7.2 Hz, 1 H,
J ¼ 6.9 Hz, 3 H, CH3). 13C NMR (75 MHz, CDCl3):
d
151.4, 138.1, 132.0,
ArH), 8.97 (d, J ¼ 7.6 Hz, 1 H, ArH), 8.67 (d, J ¼ 7.1 Hz, 1 H, ArH), 8.49
(d, J ¼ 7.1 Hz, 1 H, ArH), 8.10 (d, J ¼ 7.1 Hz, 1 H, ArH), 7.90e7.77 (m,
7 H, ArH), 4.76 (t, J ¼ 7.2 Hz, 2 H, CH2), 1.87 (m, 2 H, CH2), 1.09e1.04
(m, 10 H, CH2), 0.78 (t, J ¼ 7.0 Hz, 3 H, CH3). IR (KBr, cmꢀ1): 1610 (s),
1469 (s), 1359 (s), 1278 (s), 753 (m), 723 (m). TOFMS (EI) calcd for
(Mþ) C29H31BN2O2: 450.2479, found: 450.2488.
131.6, 130.1, 129.2, 128.2, 127.3, 126.8, 126.3, 125.6, 124.9, 124.4,
124.0, 123.4, 123.1, 122.6, 120.7, 46.9, 31.7, 30.2, 29.1, 28.9, 26.2, 22.7,
14.2. IR (KBr, cmꢀ1): 2925 (s), 1530 (m), 1466 (s), 1397 (m), 1359 (s),
1009 (m), 753 (s), 722 (s). TOFMS (EI) calcd for (Mþ) C29H29BrN2:
484.1514, found: 484.1511.
2.2.2.2. 1-Octyl-2-thiophen-2-yl-1H-phenanthro[9,10-d]imidazole
2.2.3.2. 5-(1-Octyl-1H-phenanthro[9,10-d]imidazol-2-yl)-thiophene-
(2b). White solid, yield: 82%. Rf ¼ 0.49 (CH2Cl2/petroleum ether
2-boronic acid (3b). 97%. Rf ¼ 0.50 (CH2Cl2/CH3OH 10:1).1H NMR
2:1). 1H NMR (300 MHz, CDCl3):
d
8.84e8.79 (m, 2 H, ArH), 8.68 (d,
(300 MHz, DMSO [D6]):
d
9.02 (d, 1 H, J ¼ 7.6 Hz, ArH), 8.91 (d,
J ¼ 8.1 Hz, 1 H, ArH), 8.24 (d, J ¼ 8.1 Hz, 1 H, ArH), 7.72e7.53 (m, 6 H,
ArH), 7.24e7.21 (m, 1 H, ArH), 4.71 (t, J ¼ 7.8 Hz, 2 H, CH2), 2.11e2.01
(m, 2 H, CH2), 1.43e1.26 (m, 10 H, CH2), 0.87 (t, J ¼ 6.5 Hz, 3 H, CH3).
J ¼ 8.0 Hz, 1 H, ArH), 8.66 (d, J ¼ 7.6 Hz, 1 H, ArH), 8.45 (d, J ¼ 8.0 Hz,
1 H, ArH), 7.87e7.70 (m, 6 H, ArH), 4.86(t, J ¼ 7.1 Hz, 2 H, CH2), 1.96
(m, 2 H, CH2), 1.34e1.17 (m, 10 H, CH2), 0.81 (t, J ¼ 6.7 Hz, 3 H, CH3).
IR (KBr, cmꢀ1): 1613 (s),1468 (s),1359 (s),1277 (s), 768 (m), 725 (m).
TOFMS (EI) calcd for (Mþ) C27H29BN2O2S: 456.2043, found:
456.1957.
13C NMR (75 MHz, CDCl3):
d 145.8, 138.0, 132.5, 129.1, 128.1, 128.0,
127.6, 127.3, 127.2, 126.7, 126.5, 125.5, 124.7, 124.3, 123.1, 123.0,
122.8, 120.4, 46.8, 31.8, 30.3, 29.2, 28.9, 26.4, 22.7, 14.2. IR (KBr,
cmꢀ1): 2921 (s), 1606 (m), 1521 (m), 1478 (s), 1448 (s), 1362 (s), 1359
(s), 851 (m), 756 (s), 689 (s). TOFMS (EI) calcd for (Mþ) C27H28N2S:
412.1973, found: 412.1957.
2.2.3.3. 4-(6,9-Dimethoxy-1-octyl-1H-phenanthro[9,10-d]imidazol-
2-yl)-phenyl-boronic acid (3c). White solid, yield: 86%. Rf ¼ 0.68
(CH2Cl2/CH3OH 10:1). 1H NMR (300 MHz, DMSO [D6]):
d 8.65 (d,
2.2.2.3. 2-(4-Bromophenyl)-6,9-dimethoxy-1-octyl-1H-phenanthro
J ¼ 8.7 Hz,1 H, ArH), 8.39e8.32 (m, 2 H, ArH), 8.27 (d, J ¼ 7.8 Hz, 1 H,
ArH), 8.10e7.90 (m, 4 H), 7.51e7.45 (m, 2 H, ArH), 4.63 (t, J ¼ 7.5 Hz,
2 H, CH2), 4.04 (s, 3 H, OCH3), 4.02 (s, 3 H, OCH3), 1.78 (m, 2 H, CH2),
1.15e1.04 (m,10 H, CH2), 0.78 (t, J ¼ 7.0 Hz, 3 H, CH3). IR (KBr, cmꢀ1):
1610 (s), 1463 (s), 1362 (s), 1231 (s), 1044 (m), 1019 (m). TOFMS (EI)
calcd for (Mþ) C31H35BN2O4: 510.2690, found: 510.2598.
[9,10-d]imidazole (2c). White solid, yield: 93%. Rf ¼ 0.31 (CH2Cl2/
petroleum ether 2:1). 1H NMR (300 MHz, CDCl3):
d 8.74 (d,
J ¼ 9.0 Hz, 1 H, ArH), 8.15 (d, J ¼ 9.0 Hz, 1 H, ArH), 8.01 (s, 1 H, ArH),
7.87 (s, 1 H, ArH), 7.68 (m, 4 H, ArH), 7.33 (d, J ¼ 9.0 Hz, 1 H, ArH),
7.18 (m, 1 H, ArH), 4.67 (t, J ¼ 7.5 Hz, 2 H, CH2), 4.06 (s, 3 H, OCH3),