The Journal of Organic Chemistry
mL/min) using UV (297 nm) detector. DFT calculation study
Page 4 of 7
was added sodium hydrogen carbonate (54 mg, 0.6 mmol) and
the resulting mixture was stirred at room temperature for 24 h.
The resulting mixture was poured into aq ammonium chloride
and the organic product was extacted three times with dichloro-
methane. The solution was dried over anhydrous sodium sulfate
and concentrated under reduced pressure to leave a crude oil.
Purification by chromatography on silica gel using hexane/me-
thyl acetate = 1:1 afforded 126 mg of 8a (74% yield), which
was confirmed to be identical with the authentic sample.
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was carried out with SPARTAN version 16 or Gaussian version
9.0 in a B3LYP/6-31G level. Unless specified, chemicals were
purchased and used without furhter purification. Preparation of
3,3'-dimethyl-2,2'-bithiophene (4) and 5,5'-Dibromo-3,3'-dime-
thyl-2,2'-bithiophene (5) were performed in a manner shown in
the literature.12 N,N-Bis(2-nitrobenzenesulfonyl)-1,2-ethylene-
diamine (7a) and N,N-Bis(2-nitrobenzenesulfonyl)-1,4-butane-
diamine (7c) were prepared in a manner as shown in the litera-
ture.13,14 V70 (2,2'-Azobis(4-methoxy-2,4-dimethylvaleroni-
trile)) was purchased from TCI Co Ltd. and stored in the freezer.
N,N-Bis(2-nitrobenzenesulfonyl)-1,3-propanediamine (7b):
To a solution of 1,3-propanediamine (231 mg, 3.1 mmol) in
THF (6.2 mL)/H2O (6.2 mL) were added sodium hydrogen car-
bonate (712 mg, 8.5 mmol) and 2-nitrobenzenesulfonyl chlo-
ride (NsCl,.1.30 g, 5.9 mmol). The resulting mixture was stirred
at room temperature for 18 h. The resulting mixture was poured
into water and the organic product was extracted three times
with dichloromethane. The solution was dried over anhydrous
sodium sulfate and concentration of the solvent under reduced
pressure afforded 1.09 g of 7b (84% yield). 1H NMR (400 MHz,
CDCl3) δ 1.81 (quint, J = 6.4 Hz, 2H), 3.25 (dt, J = 6.4, 6.4 Hz,
4H), 5.56 (t, J = 6.4 Hz, 2H), 7.73-7.81 (m, 4H), 7.86-7.90 (m,
2H), 8.14-8.18 (m, 2H). 13C{1H} NMR δ 30.4, 40.1, 125.5,
131.0, 133.0, 133.4, 133.7, 148.0; IR (ATR) 1536, 1413, 1339,
1163, 1162, 1064, 855 cm-1; HRMS (DART+): calcd for
C15H17N4O8S2 (M+H): 445.0488, Found: 445.0490.
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5,5'-Dibromo-3,3'-bis(bromomethyl)-2,2'-bithiophene (6):
To a solution of bromobithiophene 5 in 40 mL carbon tetrachlo-
ride was added NBS (11.1 g, 36 mmol) followed by addition of
V70 (11.1 g, 36 mmol). After stirring at room temperature for 5
h, the mixture was concentrated under reduced pressure to leave
a crude oil, which was purifeid by column chromatography on
silica gel to afford 12.3 g of 6 (61% yield) as a colorless solid.
1H NMR (400 MHz, CDCl3) δ 4.31 (s, 4H), 7.15 (s, 2H).
13C{1H} NMR (100 MHz, CDCl3) δ 24.77, 65.0, 130.5, 132.1,
139.2. IR (ATR) 3091, 3061, 3026, 1652, 1518, 1434, 1204,
1185, 994, 932, 829 cm-1. HRMS (DART+) calcd for
C10H779Br281Br2S2 (M+H): 510.6682, Found: 510.6702.
6,9-Diaza-[2,1-b:3,4-b']bis(5-bromothieno)-6,9-bis(2-nitro-
benzenesulfonyl)-cyclodecane (8a): To 20 mL Schlenk tube
equipped with a magnetic stirring bar were dissolved 5,5'-di-
bromo-3,3'-bis(bromomethyl)-2,2'-bithiophene (6, 1.1 g, 2.0
mmol) and N,N-bis(2-nitrobenzenesulfonyl)-1,2-ethylenedia-
mine (7a, 43 mg, 2.0 mmol) in 10 mL DMF. K2CO3 (1.1 g, 8.0
mmol) was added to the resulting solution at room temperature
and stirring was continued for 0.5 h at 60 °C. The resulting mix-
ture was poured into water to form a precipitate, which was
washed with water, methanol, and diethyl ether repeatedly to
leave a crude solid. Purification by chromatography on silica
gel using dichlorome−methanol = 5:1 as an eluent afforded 1.43
g of 8a (92% yield) as a colorless solid. Mp. 222.4-223.9 °C. 1H
NMR (CDCl3) δ 3.05 (brs, 2H), 3.38 (brs, 2H), 3.98 (d, J = 14.8
Hz, 2H), 4.81 (d, J = 14.8 Hz, 2H), 7.20 (s, 2H), 7.66-7.77 (m,
6H), 7.98-8.05 (m, 2H); 13C{1H} NMR (100 MHz, CDCl3): δ
147.9, 139.1, 134.0, 132.7, 132.2, 132.0, 131.9, 130.8, 124.5,
115.5, 31.6, 22.6; IR (ATR) 1531, 1350, 1163, 1123, 1065, 975,
926, 851, 812 cm-1; HRMS (ESI+): calcd for
C24H1979Br81BrN4O8S4 (M+H): 778.8432, Found: 778.8456.
6,10-Diaza-[2,1-b:3,4-b']bis(5-bromothieno)-cycloundecane
(8b): Synthesis of 8b was carried out in a manner to that of 8a
with 7b (44 mg, 0.1 mmol) and bithiophene 6 (51 mg, 0.1
mmol) in 0.5 mL DMF at 60 °C for 3 h to afford 67 mg of 8b
(83% yield) as a colorless solid. Mp. 273.7-275.8 °C. 1H NMR
(400 MHz, DMSO-d6) δ 1.33 (quint, J = 6.6 Hz, 2H), 2.89-3.05
(m, 2H), 3.05-3.21 (m, 2H), 4.16 (d, J = 15.1 Hz, 2H), 4.59 (d,
J = 15.1 Hz, 2H), 7.25 (s, 2H), , 7.85 (ddd, J = 1.4, 7.8, 7.8 Hz,
2H), 7.91 (ddd, J = 1.4, 7.8, 7.8 Hz, 2H), 8.01 (dd, J =1.4, 7.8
Hz, 2H), 8.05 (dd, J=1.4, 7.8 Hz, 2H). 13C{1H} NMR (100 MHz,
DMSO-d6) δ 25.3, 44.2, 46.2, 114.2, 124.5, 130.0, 130.4, 130.8,
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132.75 (HMQC correlation with H δ 7.25), 132.75 (HMQC
correlation with 1H δ 7.85), 134.9, 139.2, 147.9. IR (ATR) 1536,
1361, 1338, 1177, 1160, 974, 852 cm-1. HRMS (ESI+): calcd
for C25H2179Br81BrN4O8S4 (M+H): 792.8595, Found: 792.8589.
6,11-Diaza-[2,1-b:3,4-b']bis(5-bromothieno)-cyclododecane
(8c): Synthesis of 8b was carried out in a manner to that of 8a
with 7c (147 mg, 0.3 mmol) and bithiophene 6 (160 mg, 0.3
mmol) in 1.5 mL DMF at 60 °C for 3 h to afford 149 mg of 8c
6,9-Diaza-[2,1-b:3,4-b']bis(5-bromothieno)-cyclodecane
(9a): To a solution of 8a (78 mg, 0.1 mmol) in DMF (1.5 mL)
was added 1-dodecanethiol (0.12 mL, 0.5 mmol) and DBU
(0.07 mL, 0.5 mmol). The mixture was stirred at room temper-
ature for 17 h. The resulting reaction mixture was poured into
aq sodium hydrogen carbonate to result in phase separation. The
aqueous layer was extracted three times with dichloromethane
and the organic layer was dried over anhydrous sodium sulfate.
Removal of the solvent left a crude oil, which was subjected to
purification by column chromatography on silica gel to afford
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as a colorless solid (62% yield). Mp. 237.8-239.3 °C. H NMR
(400 MHz, DMSO-d6) 1.36-1.46 (brs, 4H), 3.02-3.10 (brs, 4H),
4.15 (d, J = 15.4 Hz, 2H), 4.80 (d, J = 15.4 Hz, 2H), 7.24 (s,
2H), 7.62-7.77 (m, 6H), 7.98-8.01 (m, 2H). 13C{1H} NMR (100
MHz, DMSO-d6) δ 25.2, 45.1, 46.7, 145.5, 124.7, 129.7, 130.2,
131.0, 131.9, 132.9, 134.9, 139.3, 147.8. IR (ATR) 1543, 1347,
1159, 988, 924, 851 cm-1. HRMS (ESI+): calcd for C26H2379Br
81BrN4O8S4 (M+H): 806.8745, Found: 806.8761.
Attempted cyclization of bithiophene 6 with N, N'-bis(t-
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35 mg of 9a (85%) as a colorless oil. H NMR (400 MHz,
butoxycarbonyl)-1,2-ethylenediamine
(Boc-
CDCl3) δ 2.67 (s, 4H), 3.75 (s, 4H), 6.99 (s, 2H), 13C{1H} NMR
(100 MHz, CDCl3) δ 41.7, 42.5, 113.9, 131.0, 131.5, 142.3, IR
(ATR) 3367, 2923, 2850, 1723, 1586, 1451, 1127, 837 cm-1,
HRMS (DART+): calcd for C12H1381Br2N2S2 (M+H): 410.8846,
Found: 410.8862.
NHCH2CH2NHBoc): To a 20 mL Schlenk tube were added N,
N'-t-butoxycarbonyl-1,2-ethlenediamine (26 mg, 0.1 mmol)
and anhydrous DMF (5.0 mL) under nitrogen atmosphere. So-
dium hydride (60% in mineral oil, 16 mg, 0.1 mmol) was then
added at 0 °C, and resulting mixture were stirred for 0.5 h at
room temperature. To the solution tetrabromobithiophene 6
(53.5 mg, 0.105 mmol) was added. After stirring at room tem-
Reinstallation of Ns group leading to 9a: To a solution of 9a
(91 mg, 0.22 mmol) and 2-nitrobenzenesulfonyl chloride (NsCl,
100 mg, 0.45 mmol) in a mixture of THF/H2O (0.5 mL/0.5 mL)
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