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2
60.3, 158.0, 138.0, 112.8, 105.7, 72.0, 70.8, 70.0, 59.0, 34.5,
9.4.
dry ether (20.0 mL) was added via a syringe. The mixture
was stirred at room temperature for 1 h, then the reaction
was quenched with water, and the organic layer was
extracted with diethyl ether. The combined organic layers
Synthesis of 6-Amino-3-bromo-2-[3-(2-methoxyethoxy)
propyl]pyridine (7)
To a solution of 6 (7.71 g, 36.7 mmol) in dry dichlorome-
thane (100 mL) at 0 C, 2,4,4,6-tetrabromo-2,5-cyclohexadie-
none (17.5 g, 42.6 mmol) was slowly added. The mixture
were dried over MgSO . The solvent was removed under
4
reduced pressure by rotary evaporator, and the residue was
ꢀ
purified by means of column chromatography (SiO , hexane/
2
EtOAc ¼ 4/1), followed by Kugelrohr distillation (0.04
ꢀ
was stirred at 0 C for 6 h. The reaction was quenched with
ꢀ
mmHg, 110–115 C) to afford 8 as a colorless oil (2.85 g,
aqueous 3 M HCl solution, and the aqueous layer was
washed with dichloromethane and then made basic to
around pH 14 with aqueous 10% NaOH solution. The or-
ganic layer was extracted with dichloromethane, and the
7
1%).
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H NMR (600 MHz, CDCl ): d ¼ 7.86 (d, J ¼ 8.2 Hz, 1 H),
3
7
.03 (d, J ¼ 8.2 Hz, 1 H), 3.61–3.60 (m, 2 H), 3.59–3.54 (m,
4
7
H), 3.39 (s, 3 H), 3.00 (t, J ¼ 7.8 Hz, 2 H), 2.03 (quint, J ¼
combined organic layers were dried over MgSO . The solvent
4
1
3
.8 Hz, 2 H); C NMR (151 MHz, CDCl ): d ¼ 164.2, 148.6,
3
was removed under reduced pressure in a rotary evaporator,
and the residue was recrystallized from dichloromethane–
141.2, 126.9, 94.4, 71.9, 70.4, 69.9, 59.1, 37.4, 28.3.
hexane to give 7 as a white solid (9.13 g, 86%): mp ¼
Synthesis of 6-Bromo-2-[3-(2-methoxyethoxy)propyl]
pyridin-3-yl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2)
A round-bottomed flask equipped with a three-way stopcock
was heated under reduced pressure and then cooled to
room temperature under an argon atmosphere. Dibromopyri-
dine 3 (3.54 g, 10.0 mmol) was placed in the flask, and the
atmosphere in the flask was replaced with argon. Dry diethyl
ether (30.0 mL) was added into the flask via a syringe, and
ꢀ
1
09.7–110.8 C.
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H NMR (600 MHz, CDCl ): d ¼ 7.46 (d, J ¼ 8.4 Hz, 1 H),
3
6
.23 (d, J ¼ 8.4 Hz, 1 H), 4.47 (br s, 2 H), 3.61–3.59 (m, 2
H), 3.57–3.53 (m, 4 H), 3.39 (s, 3 H), 2.82 (t, J ¼ 7.2 Hz, 2
1
3
H), 1.99 (quint, J ¼ 7.2 Hz, 2 H); C NMR (151 MHz, CDCl ):
3
d ¼ 158.0, 156.9, 141.5, 108.5, 107.7, 72.0, 70.8, 69.9, 59.0,
3
3.7, 28.2.
ꢀ
the mixture was stirred at ꢂ78 C. Then, n-butyl lithium (1.6
Synthesis of 3,6-Dibromo-2-[3-(2-methoxyethoxy)
propyl]pyridine (3)
A mixture of 7 (0.98 g, 3.39 mmol) and bromine (0.53 mL,
M in hexane, 7.5 mL, 12.0 mmol) was added via a syringe,
ꢀ
and stirring was continued at ꢂ78 C for 3 h. To this mix-
ture, a solution of triisopropyl borate (2.29 g, 12.2 mmol) in
dry ether (10.0 mL) was added via a syringe. The mixture
was stirred at room temperature for 2 h, then a solution of
pinacol (1.61 g, 13.7 mmol) in dry ether (10.0 mL) was
added, and after 5 min, acetic acid (0.60 mL, 10.5 mmol)
was added. Stirring was continued at room temperature for
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0.0 mmol) in aqueous 48% HBr solution (5.5 mL) was
ꢀ
stirred at 0 C for 0.5 h. An aqueous solution (3.0 mL) of
NaNO (0.72 g, 10.0 mmol) was added to the reaction mix-
2
ꢀ
ꢀ
ture at 0 C, and stirring was continued at 0 C for 4 h. The
resulting solution was neutralized with aqueous 10% NaOH
solution and extracted with dichloromethane. The combined
2
h. The reaction was quenched with water, and the organic
organic layers were washed with aqueous 10% Na S O so-
2
2
3
layer was extracted with diethyl ether. The combined organic
lution and water and dried over MgSO . The solvent was
4
layers were dried over MgSO . The solvent was removed
4
removed under reduced pressure in a rotary evaporator, and
the residue was purified by means of column chromatogra-
under reduced pressure in a rotary evaporator, and the resi-
due was purified by means of Kugelrohr distillation (0.07–
ꢀ
phy (SiO
2
, hexane/EtOAc ¼ 3/1) to afford 3 as a pale yellow
0
.09 mmHg, 142–144 C) to afford 2 as a colorless oil (2.56
oil (1.03 g, 86%).
g, 64%).
1
1
H NMR (600 MHz, CDCl ): d ¼ 7.62 (d, J ¼ 8.2 Hz, 1 H),
3
H NMR (600 MHz, CDCl ): d ¼ 7.84 (d, J ¼ 7.9 Hz, 1 H),
3
7
4
7
.18 (d, J ¼ 8.2 Hz, 1 H), 3.61–3.59 (m, 2 H), 3.58–3.54 (m,
7
.29 (d, J ¼ 7.9 Hz, 1 H), 3.59–3.52 (m, 6 H), 3.38 (s, 3 H),
H), 3.39 (s, 3 H), 2.99 (t, J ¼ 7.7 Hz, 2 H), 2.05 (quint, J ¼
3
.08 (t, J ¼ 7.6 Hz, 2 H), 2.00–1.95 (m, 2 H), 1.34 (s, 12 H);
1
3
1
3
.7 Hz, 2 H); C NMR (151 MHz, CDCl ): d ¼ 161.5, 142.2,
3
C NMR (151 MHz, CDCl ): d ¼ 164.9, 146.0, 143.9, 124.6,
3
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39.7, 126.8, 120.3, 72.0, 70.5, 70.0, 59.1, 33.8, 27.9.
8
4.1, 71.9, 70.9, 69.6, 58.9, 34.2, 30.5, 24.7, 24.6.
Synthesis of 6-Bromo-3-iodo-2-[3-(2-methoxyethoxy)
propyl]pyridine (8)
Polymerization
Synthesis of HT-PMEPPy
A round-bottomed flask equipped with a three-way stopcock
was heated under reduced pressure and then cooled to
room temperature under an argon atmosphere. Dibromopyri-
dine 3 (3.54 g, 10.0 mmol) was placed in the flask, and the
atmosphere in the flask was replaced with argon. Dry diethyl
ether (30.0 mL) was added into the flask via a syringe, and
Kumada-Tamao Coupling Polymerization. All glass appa-
ratus were dried before use. The addition of reagents into a
reaction flask and the withdrawal of a small aliquot of the
reaction mixture for analysis were carried out via a syringe
from a three-way stopcock under a stream of nitrogen. A
round-bottomed flask equipped with a three-way stopcock
containing lithium chloride (24.7 mg, 0.65 mmol) was heated
under reduced pressure and then cooled to room tempera-
ture under an argon atmosphere. Monomer precursor 8
(0.220 g, 0.55 mmol) was placed in the flask, and the
ꢀ
the mixture was stirred at ꢂ78 C. Then, n-butyl lithium (1.6
M in hexane, 7.5 mL, 12.0 mmol) was added via a syringe,
ꢀ
and stirring was continued at ꢂ78 C for 3 h. To this mix-
ture, a solution of 1,2-diiodoethane (3.13 g, 11.1 mmol) in
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Nanashima, Yutaka
