A R T I C L E S
Letizia et al.
Synthesis of 2-Octyldodecylamine (6). Iodoalkane 5 (5.90 g,
14.5 mmol) and potassium phthalimide (2.94 g, 15.9 mmol) were
taken up in 25 mL of DMF and vigorously stirred for 72 h at 25
°C. The reaction mixture was then taken up in 200 mL of pentane,
washed four times with 100 mL of water, passed through a 3 cm
silica gel plug, and concentrated to give a colorless oil. The oil
was next taken up in 150 mL of ethanol, 4 mL of hydrazine hydrate
was added, and the mixture was refluxed overnight. The resulting
precipitate was collected by filtration and dissolved in 100 mL of
water, and the solution was made alkaline by addition of 6 M NaOH
(aq). The resulting mixture was then taken up in 200 mL of pentane,
washed four times with 100 mL of water and once with 70 mL of
brine, and concentrated to give a colorless oil (3.08 g, 72% yield).
Anal. Calcd for C20H43N: C, 80.73; H, 14.57. Found: C, 80.78; H,
(t, J ) 7.5 Hz, 2H), 1.71 (m, 1H), 1.37 (m, 2H), 1.26 (b, 16H),
0.89 (t, J ) 7.0 Hz, 9H). Mp 52-54 °C. MS (EI): m/z (%) 389.3
(100) [M+].
Synthesis of N-(2-Ethylhexyl)-2,2′-bithiophene-3,3′-dicar-
boximide (M1, 12). A light yellow solid (1.10 g, 42% yield) was
obtained upon concentration of the main fractions. Anal. Calcd for
C19H21NO2S2: C, 62.21; H, 6.09. Found: C, 62.09; H, 6.02. 1H NMR
(CDCl3): 7.69 (d, J ) 5.5 Hz, 2H), 7.25 (d, J ) 5.5 Hz, 2H), 4.20
(t, J ) 7.5 Hz, 2H), 1.80 (m, J ) 8.0 Hz, 1H), 1.29 (b, 8H), 0.89
(t, J ) 7.5 Hz, 6H). Mp 54-56 °C. MS (EI): m/z (%) 347.1 (100)
[M+].
Synthesis of N-(2-Octyldodecyl)-5-5′dibromo-2,2′-bithio-
phene-3,3′-dicarboximide (13). Bromine (1.41 g, 8.84 mmol) was
added to a solution of imide 7 (1.14 g, 2.21 mmol) in 30 mL of
dichloromethane followed by addition of ferric chloride (7.2 mg,
0.044 mmol). The reaction mixture was allowed to stir in the dark
for 6 h before 5 mL of sat. Na2SO3 (aq) was added and stirring
continued for 0.5 h. The reaction mixture was then poured into
150 mL of dichloromethane, washed three times with 100 mL of
water and once with 70 mL of brine, and dried over Mg2SO4. The
organic solution was next filtered and concentrated by evaporation
to give a light yellow solid (1.40, 94% yield). Anal. Calcd for
C30H43Br2NO2S2: 53.49; H, 6.43. Found: C, 53.36; H, 6.40. 1H
NMR (CDCl3): 7.68 (s, 2H), 4.18 (d, J ) 7.5 Hz, 2H), 1.86 (m,
1H), 1.34-1.20 (b, 32H), 0.89 (t, J ) 7.5 Hz, 6H). Mp 44-46 °C.
The same procedure was followed for compounds 14-18 as
described below.
Synthesis of N-Hexyl-5,5′-dibromo-2,2′-bithiophene-3,3′-di-
carboximide (14). A light yellow solid (84% yield) was obtained
upon concentration. Anal. Calcd for C16H15Br2NO2S2: C, 40.27;
H, 3.17. Found: C, 40.30; H, 3.13. 1H NMR (CDCl3): 7.72 (s, 2H),
4.16 (t, J ) 7.0 Hz, 2H), 1.69 (m, J ) 7.0 Hz, 2H), 1.33-1.27 (b,
6H), 0.89 (t, J ) 7.5 Hz, 3H). Mp 149-150 °C. MS (EI): m/z (%)
319.0 (100) [M+].
Synthesis of N-Octyl-5,5′-dibromo-2,2′-bithiophene-3,3′-di-
carboximide (15). A light yellow solid (95% yield) was obtained
upon concentration. Anal. Calcd for C18H19Br2NO2S2: C, 42.79;
H, 3.79. Found: C, 42.66; H, 3.82. 1H NMR (CDCl3): 7.70 (s, 2H),
4.15 (t, J ) 7.0 Hz, 2H), 1.67 (m, J ) 7.0 Hz, 2H), 1.35-1.25 (b,
10H), 0.89 (t, J ) 7.5 Hz, 3H). Mp 133-135 °C. MS (EI): m/z
(%) 347.1 (100) [M+].
1
14.52. H NMR (CDCl3): 2.60 (d, J ) 5.0 Hz, 2H), 2.00 (t, J )
5.0 Hz, 1H), 1.30-1.20 (b, 32H), 0.89 (t, J ) 7.5 Hz, 6H). MS
(EI): m/z (%) 297.34 (100) [M+].
Synthesis of N-(2-Octyldodecyl)-2,2′-bithiophene-3,3′-dicar-
boximide (7). A dry 8 mL microwave reaction tube was charged
with a microstirbar, anhydride 4 (354 mg, 1.50 mmol), 4-(dim-
ethylamino)pyridine (61 mg, 0.50 mmol), and 5 mL of toluene.
Next, 2-octyldodecylamine (446 mg, 1.5 mmol) was added dropwise
to the suspension over 15 min, and the reaction was allowed to stir
for an additional 15 min until no solid remained. The reaction tube
was then irradiated with microwaves (PMAX ) 300 W) for 2 h at a
constant temperature of 220 °C. This procedure was repeated four
more times, and the five reaction mixtures were combined in 250
mL of diethyl ether, washed six times with 150 mL of water and
one time with 100 mL of brine, and the organics dried over Mg2SO4.
After filtration, the solvent was removed by evaporation to afford
1
a yellow oil (90% pure by H NMR) that was purified by column
chromatography on silica gel with a mixture of diethyl ether (10%)
and hexane (90%) as the eluent. A light yellow oil (1.45 g, 37%
yield) was obtained upon concentration of the main fractions. Anal.
Calcd for C30H45NO2S2: C, 69.85. H, 8.79; Found: C, 69.79; H,
8.71. 1H NMR (CDCl3): 7.76 (d, J ) 5.5 Hz, 2H), 7.24 (d, J ) 5.5
Hz, 2H), 4.20 (t, J ) 7.5 Hz, 2H), 1.71 (m, 1H), 1.37 (m, 4H),
1.26 (b, 28H), 0.89 (t, J ) 7.0 Hz, 6H). MS (EI): m/z (%) 515.29
(100) [M+]. The same procedure was followed for the synthesis
of compounds 8-12 as described below.
Synthesis of N-Hexyl-2,2′-bithiophene-3,3′-dicarboximide
(8). A light yellow solid (1.65 g, 69% yield) was obtained upon
concentration of the main fractions. Anal. Calcd for C16H17NO2S2:
Synthesis of N-Dodecyl-5,5′-dibromo-2,2′-bithiophene-3,3′-
dicarboximide (16). A light yellow solid (98% yield) was obtained
upon concentration. Anal. Calcd for C22H27Br2NO2S2: C, 47.07;
H, 4.85. Found: C, 47.05; H, 4.77. 1H NMR (CDCl3): 7.70 (s, 2H),
4.15 (t, J ) 7.0 Hz, 2H), 1.66 (m, 2H), 1.35-1.27 (b, 18H), 0.89
(t, J ) 7.0 Hz, 3H). Mp 117-119 °C. MS (EI): m/z (%) 403.3
(100) [M+].
1
C, 60.16; H, 5.36. Found: C, 60.05; H, 5.41. H NMR (CDCl3):
7.76 (d, J ) 4.5 Hz, 2H), 7.24 (d, J ) 5.5 Hz, 2H), 4.20 (t, J ) 7.5
Hz, 2H), 1.71 (m, J ) 8.0 Hz, 2H), 1.40 (m, 2H), 1.34 (m, 4H),
0.90 (t, J ) 7.5 Hz, 3H). Mp 90-91 °C. MS (EI): m/z (%) 319.4
(100) [M+].
Synthesis of N-Octyl-2,2′-bithiophene-3,3′-dicarboximide
(9). A light yellow solid (1.87 g, 72% yield) was obtained upon
concentration of the main fractions. Anal. Calcd for C18H21NO2S2:
Synthesis of N-(4,8-Dimethylnonyl)-5,5′-dibromo-2,2′-bi-
thiophene-3,3′-dicarboximide (17). A light yellow solid (92%
yield) was obtained upon concentration. Anal. Calcd for
C21H25Br2NO2S2: C, 46.08; H, 4.60. Found: C, 45.99; H, 4.65. 1H
NMR (CDCl3): 7.71 (s, J ) 5.5 Hz, 2H), 4.15 (t, J ) 7.5 Hz, 2H),
1.73 (m, 1H), 1.34 (m, 2H), 1.29 (b, 16H), 0.89 (t, J ) 7.0 Hz,
9H). Mp 127-130 °C. MS (EI): m/z (%) 389.0 (100) [M+].
Synthesis of N-(2-Ethylhexyl)-5,5′-dibromo-2,2′-bithio-
phene-3,3′-dicarboximide (18). A light yellow solid (95% yield)
was obtained upon concentration. Anal. Calcd for C19H19Br2NO2S2:
1
C, 62.21; H, 6.09. Found: C, 62.18; H, 3.90. H NMR (CDCl3):
7.76 (d, J ) 4.5 Hz, 2H), 7.24 (d, J ) 5.5 Hz, 2H), 4.20 (t, J ) 7.5
Hz, 2H), 1.71 (m, J ) 8.0 Hz, 2H), 1.40 (m, 2H), 1.36-1.28 (b,
10H), 0.89 (t, J ) 7.5 Hz, 3H). Mp 71-72 °C. MS (EI): m/z (%)
346.9 (100) [M+].
Synthesis of N-Dodecyl-2,2′-bithiophene-3,3′-dicarboximide
(10). A light yellow solid (1.79 g, 59% yield) was obtained upon
concentration of the main fractions. Anal. Calcd for C22H29NO2S2:
1
1
C, 42.79; H, 3.79. Found: C, 42.57; H, 3.84. H NMR (CDCl3):
C, 65.47; H, 7.24. Found: C, 65.31; H, 7.41. H NMR (CDCl3):
7.69 (s, 2H), 4.19 (d, J ) 7.0 Hz, 2H), 1.90 (m, 1H), 1.36-1.22
(b, 8H), 0.89 (m, 6H). Mp 154-147 °C. MS (EI): m/z (%) 347.1
(100) [M+].
Synthesis of Poly(N-(2-octyldodecyl)-2,2′-bithiophene-3,3′-
dicarboximide) (P1). A solution of imide 23 (1.21 g, 1.80 mmol)
in 70 mL of DMF was added to a solution of bis(1,5-cycloocta-
diene)nickel(0) (0.594 g, 2.16 mmol), 1,5-cyclooctadiene (0.195
g, 1.80 mmol), and 2,2′-bipyridine (0.337 g, 2.16 mmol) which
had been stirring for 20 min in 10 mL of DMF. The reaction mixture
7.76 (d, J ) 5.5 Hz, 2H), 7.24 (d, J ) 5.5 Hz, 2H), 4.24 (m, 2H),
1.69 (m, 2H), 1.56 (m, 4H), 1.37 (m, 2H), 1.26 (b, 2H), 1.17 (m,
2H), 1.00 (d, J ) 6.5 Hz, 3H), 0.87 (d, J ) 6.5 Hz, 6H). Mp 60-61
°C. MS (EI): m/z (%) 403.3 (100) [M+].
Synthesis of N-(4,8-Dimethylnonyl)-2,2′-bithiophene-3,3′-
dicarboximide (11). A light yellow solid (1.78 g, 61% yield) was
obtained upon concentration of the main fractions. Anal. Calcd for
C21H27NO2S2: C, 64.74; H, 6.99. Found: C, 64.68; H, 7.01. 1H NMR
(CDCl3): 7.76 (d, J ) 5.5 Hz, 2H), 7.25 (d, J ) 5.5 Hz, 2H), 4.20
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9682 J. AM. CHEM. SOC. VOL. 130, NO. 30, 2008