3474 Chem. Mater., Vol. 22, No. 11, 2010
Nguyen et al.
137.09, 136.46, 133.33, 129.46, 125.20, 124.48, 120.12, 118.47,
116.94, 89.62, 68.87, 68.49, 68.36, 67.66, 67.61, 67.58, 67.53,
67.50, 63.81, 56.05 (OCH3), 48.39 (C9), 36.46 (CH2CH2O).
HRMS calcd C47H77O16I for 1025.0207; found 1024.9921.
2-Iodo-7-nitro-9,9-di-2-(2-ethoxyethoxy)ethylfluorene 5a. 2-
Iodo-9,9-di-2-(2-ethoxyethoxy)ethylfluorene 4a (0.53 g, 1 mmol)
was dissolved in a mixture of acetic acid (2 mL) and acetic
anhydride (2 mL) in a 50 mL flask. To this solution, nitric acid
(0.30 g, 0.22 mL, 3 mmol) was added, and the reaction mixture
was stirred overnight. The resulting solution was poured into
water (50 mL), followed by addition of CH2Cl2 (40 mL). The
organic phase was removed, and then the aqueous phase was
extracted 3 times with CH2Cl2 (40 mL). The organic phases were
combined, washed with water, and then dried over Na2SO4. The
filtrate was removed under reduced pressure to obtain a crude
product which was further purified on a silica gel column using
hexane and EtOAc as the eluent to obtain 2-iodo-7-nitro-9,9-di-
2-(2-ethoxy ethoxy)ethylfluorene 5a (0.30 g, 0.50 mmol) with mp
of 55-56 ꢀC as a light yellow solid (50% yd). 1HNMR (500 MHz,
CDCl3, δ): 8.15-8.17 (m, Ar-H, 2H), 7.80-7.82 (s, 1H), 7.75
-7.78 (m, Ar-H, 2H), 7.35-7.38 (m, 1H), 3.38-3.42 (m, 4H),
3.28-3.32 (m, 4H), 3.15-3.19 (m, OCH2, 4H), 2.80-2.88 (dd,
CH2CH2O, 4H), 2.40-2,48 (dd, CH3CH2O, 4H), 1.10-1,15 (m,
CH3, 6H). 13C NMR (500 MHz, CDCl3, δ): 151.30, 148.32,
140.07, 139.46, 136.27, 132.45, 128.01, 127.82, 123.52, 121.65,
119.92, 92.64 (C-I), 70.07, 69.67, 66.89, 66.60, 51.37 (C9), 39.55
(CH2CH2O), 15.10 (CH3). HRMS calcd C25H32NIO6 for
569.4359; found 569.1268.
7.55-7.57 (m, Ar-H, 1H), 7.48-7.52 (m, Ar-H, 1H), 7.35-7.38
(m, Ar-H, 1H), 7.22-7.30 (m, Ar-H, 2H), 3.05-3.38 (m, OCH2,
12H), 2.75-2.81 (dd, CH2CH2O, 4H), 2.38-2.45 (m, CH3CH2O,
4H), 1.0-1.04 (m, CH3, 6H). 13C NMR (500 MHz, CDCl3, δ):
167.95 (CdN), 154.22 (sp2 C-N), 151.90, 151.80, 147.63, 146.45,
139.66, 138.34, 138.08, 135.75, 133.80, 129.89, 128.90, 128.01,
127.16, 127.05, 126.95, 126.43, 124.85, 123.70, 123.21, 121.65,
121.55, 119.88, 118.94, 70.15, 69.61, 66.86, 66.61, 51.95 (C9),
39.45 (CH2CH2), 15.05 (CH3). HRMS calcd for C40H42O6N2S,
678.8416; found 678.2827.
Compound 6b. Fluorenyl 5b (2.18 g, 1.75 mmol) was used in a
procedure identical to the synthesis of 6a above. Purification by
column chromatography, using silica gel as the stationary phase
and CH2Cl2 and CH3OH (95:5) as the eluent, provided an oily
liquid 6b (1.65 g, 1.20 mmol) in 70% yield. 1H NMR (500 MHz,
CDCl3, δ): 8.20-8.22 (dd, 2H), 8.02-8.10 (dd, 3H), 7.85-7.90
(m, 1H), 7.70-7.75 (d, 2H), 7.62-7.68 (dd, Ar-H, 3H), 7.55-
7.57 (d, Ar-H, 1H), 7.45-7.48 (m, Ar-H, 1H), 7.30-7.35 (m,
Ar-H, 1H), 7.22-7.25 (m, Ar-H, 2H), 3.40-3.62 (m, 66H),
3.30-3.38 (m, 8H), 2.70-2.80 (d, CH2CH2O, 4H), 2.38-2.41
(m, CH3CH2O, 4H). 13C NMR (500 MHz, CDCl3, δ): 167.90,
154.01, 151.7, 151.05, 147.06, 146.10, 140.00, 138.20, 138.10,
135.02, 132.89, 130.02, 129.80, 129.50, 128.07, 127.55, 126.80,
125.99, 125.80, 124.00, 123.80, 123.50, 123.20, 122.00, 120.00,
119.50, 119.00, 71.89, 71.00, 70.76, 70.63, 70.52, 70.32, 70.26,
70.04, 66.80, 59.01 (OCH3), 51.89 (C9), 39.80 (CH2CH2O).
HRMS calcd C54H70O14N2S for 1003.212; found 1002.9711.
2-Amino-7-styrylbenzothiazolyl-9,9-di-2-(2-ethoxyethoxy)ethyl-
fluorene 7a. 2-Nitro-7-styrylbenzothiazolyl-9,9-di-2-(2-ethoxy-
ethoxy)ethylfluorene 6a (1.20 g, 1.8 mmol) was dissolved in a
mixture of EtOH (25 mL) and THF (25 mL) in a 200 mL flask.
The resulting solution was degassed with N2 for 10 min, and
10% palladium on carbon (0.12 g) was then added. The solution
was heated to 60 ꢀC under N2. Hydrazine hydrate (0.50 g) was
then added dropwise to the reaction mixture over 10 min. The
solution was then refluxed at 70 ꢀC for 20 h. At the end of this
period, the solution was allowed to cool to room temperature,
filtered using a short silica gel plug, and washed with THF (100
mL). The filtrate was removed under reduced pressure, afford-
ing a crude product that was further purified on a silica gel
column, using EtOAc and THF (4:1) as eluent, to obtain 2-
amino-7-styrylbenzothiazolyl-9,9-di-2-(2-ethoxyethoxy)ethyl-
fluorene 7a (1.00 g, 1.5 mmol) as yellow solid (mp 185-188 ꢀC).
IR (neat, cm-1): 3400, 3340, 3230 (-NH2). 1H NMR (300 MHz,
CDCl3, δ): 7.95-8.05 (m, Ar-H, 3H), 7.82-7.85 (d, Ar-H,
1H), 7.58-7.62 (d, Ar-H, 2H), 7.30-7.50 (m, Ar-H, 6H),
7.10-7.18 (m, Ar-H, 2H), 6.65 (s, Ar-H, 1H), 6.56-6.58 (d,
Ar-H, 1H), 3.85 (s, NH2, 2H), 3.25-3.38 (m, OCH2, 8H),
3.15-3.18 (m, 4H), 2.62-2.78 (m, CH2CH2O, 4H), 2.21-2.42
(m, CH3CH2O, 4H), 1.02-1.12 (m, CH3, 6H). 13C NMR
(CDCl3, 300 MHz, δ): 167.87 (CdN), 154.15 (sp2 C-N),
151.70, 148.62, 146.76, 141.86, 140.55, 135.01, 134.65, 132.05,
131.24, 131.04, 128.13, 127.05, 126.87, 126.61, 126.54, 126.05,
123.33, 121.82, 121.10, 121.05, 119.10, 114.35, 110.15, 70.41,
70.00, 67.37, 66.89, 51.06 (C9), 40.40 (CH2CH2O), 15.48 (CH3).
HRMS calcd for C40H44N2O4S, 648.8586; found 648.3016.
Compound 7b. Fluorene 6b (2.40 g, 1.70 mmol) was used in a
procedure identical to the synthesis of 7a above. Purification by
column chromatography, using silica gel as the stationary phase
and CH2Cl2 and CH3OH (95:5) as the eluent, produced an oily
liquid 7b (2.05 g, 1.50 mmol) in 90% yield. IR (neat, cm-1): 3447,
3355, 3236 (-NH2), 2870, 1602, 1468, 1354, 1293, 1248, 1101
(C-O), 1031, 958, 871, 822, 762. 1H NMR (500 MHz, CDCl3,
Compound 5b. Compound 4b (1.20 g, 1 mmol) was used in a
procedure identical to the synthesis of 5a above. Purification by
column chromatography, using silica gel as the stationary phase
and CH2Cl2 and CH3OH (95:5) as the eluent, produced an oily
yellowish liquid 5b (40% yd). 1H NMR (500 MHz, CDCl3, δ):
8.25-8.30 (m, Ar-H, 2H), 7.75-7.82 (m, Ar-H, 3H), 7.50-
7.55 (m, Ar-H, 1H), 7.50 (m, Ar-H, 1H), 3.4--3.75 (m, 72H),
3.35-3.42 (s, 6H), 2.78-2.82 (d, CH2CH2O, 4H), 2.38-2.42 (d,
CH3CH2O, 4H). 13C NMR (500 MHz, CDCl3, δ): 149.85,
147.06, 144.47, 142.85, 134.74, 134.04, 130.05, 120.78, 120.0,
117.15, 116.0, 92.51 (C-I), 74.35, 74.10, 73.84, 69.16, 68.95,
68.75, 68.66, 68.55, 68.45, 68.33, 68.16, 67.79, 67.66, 66.41, 56.10
(OCH3), 49.22 (C9), 36.23 (CH2CH2O). HRMS calcd
C47H76O18NI for 1070.0183; found 1070.8651.
2-Nitro-7-styrylbenzothiazolyl-9,9-di-2-(2-ethoxyethoxy)ethyl-
fluorene 6a. 2-Iodo-7-nitro-9,9-di-2-(2-ethoxyethoxy)ethylfluorene
5a (2.00 g, 3.5 mmol) was dissolved in a mixture of DMF (25 mL)
and triethylamine (5 mL) in a 50 mL flask. The solution was
degassed with N2 for 10 min, and then palladium acetate (0.04 g,
0.18 mmol), tri(o-tolyl)phosphine (0.10 g, 3.3 mmol), and 2-(4-
ethenylphenyl)benzothiazole41 (1.00 g, 4.2 mmol) were added. The
resulting solution was heated at 90 ꢀC for 40 h. At the end of
this period, the solution was allowed to cool to room temperature
and then poured into water (200 mL) to which CH2Cl2 (50 mL)
was added. The organic phase was removed. The aqueous phase
was extracted thrice with CH2Cl2 (40 mL). The organic phases
were combined, washed with water, and dried over Na2SO4. The
filtrate was removed under reduced pressure to obtain a crude
product. Purification of the crude product was accomplished on a
silica gel column using hexane and ethyl acetate (3:7) as the eluent
to obtain 2-nitro-7-styrylbenzothiazolyl-9,9-di-2-(2-ethoxyethoxy)-
ethylfluorene 6a (1.40 g, 2.1 mmol) as yellow solid with mp of
145-147 ꢀC (60% yd). 1H NMR (500 MHz, CDCl3, δ): 8.12-8.15
(dd, Ar-H, 2H), 8.02-8.09 (dd, Ar-H, 3H), 7.83-7.88 (m, Ar-
H, 1H), 7.75-7.78 (dd, Ar-H, 2H), 7.65-7.70 (m, Ar-H, 3H),