4564
K. Uchida et al. / Tetrahedron 57 +2001) 4559±4565
4.1. Compound data
Methanol was added to the reaction mixture and extracted
with ether three times. The combined ether layers were
dried with MgSO4, ®ltered and evaporated in vacuo. The
residue was puri®ed by column chromatography on silica
gel (hexane) to give 4.93 g of 1,2-bis(3-methyl-5-phenyl-2-
thienyl)per¯uorocyclopentene (1a) in 30% yield.
4.1.1. 4-Methyl-2-phenylthiophene ꢀ6a). To an ether solu-
tion (anhydrous, 40 ml) containing 3.0 g (30.6 mmol) of
3-methylthiophene (5), 19 ml (30.6 mmol) of 1.6N n-butyl
lithium hexane solution was gradually added at 08C. The
solution was heated for 1 h under re¯ux. After cooling the
solution to 08C, 4.76 g (45.9 mmol) of trimethyl borate was
gradually added. Then the solution was stirred for 1 h at
room temperature, 20 w/w% Na2CO3 aqueous solution
(32ml), iodobenzene (6.20 g, 30.6 mmol), 50 ml of tetra-
hydrofuran, and 0.44 g of tetrakis(triphenylphosphine)
palladium(0) were added and heated for 5 h under re¯ux
with heavy stirring. After the heating was over, the reaction
mixture was poured into the water, and the reaction mixture
was extracted with ether three times. The combined organic
layer was dried with MgSO4, ®ltered and evaporated in
vacuo. The residue was puri®ed by column chromatography
on silica gel (hexane) to give 5.04 g of 4-methyl-2-phenyl-
thiophene (6a) in 89% yield.
1a: Pale yellow needles, mp 120.1±121.48C; 1H NMR
(CDCl3) d1.84 (s, 6H), 7.08 (s, 2H), 7.32 (t, 2H, J
7.2Hz), 7.39 (dd, 4H, J7.8, 7.4 Hz), 7.58 (d, 4H, J
1
7.2Hz); IR (KBr) 1590, 1460 cm 21; MS (m/z) 52 0 (M ).
Found: C, 62.21; H, 3.61%. Calcd for C27H18F6S2: C, 62.29;
H, 3.49%.
4.1.5. 1,2-Bis[3-methyl-5-ꢀp-methoxyphenyl)-2-thienyl]-
per¯uorocyclopentene ꢀ2a). 1,2-Bis[3-methyl-5-(p-meth-
oxyphenyl)-2-thienyl]per¯uorocyclopentene (2a) was syn-
thesized from 6b (1.55 g, 7.59 mmol) by the same procedure
as that used for 1a. The crude product was puri®ed
by column chromatography on silica gel (hexane/chloro-
form7/3) to give 520 mg of 2a in 25% yield.2a: Pale
1
6a: Colorless oil; 1H NMR(CDCl3) d2.29 (s, 3H), 6.85 (s,
1H), 7.13 (s, 1H), 7.25 (t, 1H, J7.4 Hz), 7.36 (dd, 2H, J
7.4, 7.2Hz), 7.58 (d, 2H, J7.2Hz); IR (KBr) 3040, 1590,
1495 cm21; MS (m/z) 174 (M1). Found: C, 75.84; H, 5.82%.
Calcd for C11H10S: C, 75.81; H, 5.78%.
yellow prisms, mp 130±1318C; H NMR (CDCl3) d2.23
(s, 6H), 3.84 (s, 6H), 6.91 (d, 4H, J8.7 Hz), 7.05 (s, 2H),
7.50 (d, 4H, J8.7 Hz); IR (KBr) 1605, 1510, 1250,
1305 cm21; MS (m/z) 580 (M1). Found: C, 59.86; H,
3.98%. Calcd for C29H22F6O2S2: C, 59.99; H, 3.82%.
4.1.6. 1,2-Bis[3-methyl-5-ꢀp-N,N-diethylaminophenyl)-2-
thienyl]per¯uorocyclopentene ꢀ3a). 1,2-Bis[3-methyl-5-
(p-N,N-diethylaminophenyl)-2-thienyl]per¯uorocyclopen-
tene (3a) was synthesized from 6c (1.33 g, 5.42mmol) by
the same procedure as that used for 1a. The crude product
was puri®ed by column chromatography on silica gel
(hexane/chloroform7/3) to give 180 mg of 3a in 10%
yield.
4.1.2. 4-Methyl-2-ꢀp-methoxyphenyl)thiophene ꢀ6b). 4-
Methyl-2-(p-methoxyphenyl)thiophene (6b) was prepared
from 3.00 g of 3-methylthiophene (30.6 mmol) and 7.16 g
(30.6 mmol) of 4-iodoanisole by the same procedure as that
used for 6a. The crude product was puri®ed by column
chromatography on silica gel (hexane/chloroform7/3) to
give 1.55 g of 6b in 25% yield.6b: Colorless prism, mp
1
56.4±57.98C; H NMR (CDCl3) d2.27 (s, 3H), 3.83 (s,
3H), 6.79 (s, 1H), 6.90 (d, 2H, J8.7 Hz), 7.01 (s, 1H),
7.50 (d, 2H, J8.7 Hz); IR (KBr) 2940, 1605, 1550, 1245,
1150 cm21; MS (m/z) 204 (M1). Found: C, 70.39; H, 6.05%.
Calcd for C12H12OS: C, 70.54; H, 5.92%.
3a: Yellow prisms, mp 90±918C; 1H NMR (CDCl3) d1.18
(t, 12H, J7.0 Hz), 1.78 (s, 6H), 3.38 (q, 8H, J7.0 Hz),
6.65 (d, 4H, J8.7 Hz), 6.88 (s, 2H), 7.43 (d, 4H, J
8.6 Hz); IR (KBr) 2960, 1350 cm21; MS (m/z) 662(M 1).
Found: C, 64.31; H, 5.60; N, 4.03%. Calcd for
C35H36F6N2S2: C, 63.44; H, 5.44; N, 4.23%.
4.1.3. 4-Methyl-2-ꢀN,N-diethylaminophenyl)thiophene ꢀ6c).
4-Methyl-2-(N,N-diethylaminophenyl)thiophene (6c) was
prepared from 1.28 g of 3-methylthiophene (13.1 mmol)
and 3.60 g (13.1 mmol) of p-N,N-diethylaminoiodobenzene
by the same procedure as that used for 6a. The crude product
was puri®ed by column chromatography on silica gel
(hexane/chloroform7/3) to give 1.33 g of 6c in 41% yield.
6c: Pale yellow plates, mp 35.3±37.08C; 1H NMR (CDCl3)
d1.18 (t, 6H, J7.0 Hz), 2.26 (s, 3H), 3.37 (q, 4H, J
7.0 Hz), 6.66 (d, 2H, J8.9 Hz), 6.71 (s, 1H), 6.93 (s, 1H),
7.43 (d, 2H, J8.9 Hz); IR (KBr) 2975, 1780 cm21; MS
(m/z) 245 (M1). Found: C, 73.25; H, 7.77; N, 5.68%.
Calcd for C15H19NS: C, 73.43; H, 7.81; N, 5.71%.
Acknowledgements
This work was supported by a Grant-in-Aid for Scienti®c
Research q No. 12640567 from the Ministry of Education,
Science, Sports, and Culture and by CREST of Japan
Science and Technology Corporation (JST).
References
4.1.4. 1,2-Bisꢀ3-methyl-5-phenyl-2-thienyl)per¯uorocyclo-
pentene ꢀ1a). To a solution containing 5.04 g (27.1 mmol)
of 6a in 70 ml of ether anhydrous, 16.9 ml of n-butyl lithium
hexane solution (1.6N, 27.1 mmol) was added at 08C under
an argon gas atmosphere. After the mixture was heated
under re¯ux for 1 h, the reaction mixture was cooled to
08C. Per¯uorocyclopentene (2.87 g, 13.55 mmol) was
added gradually and stirred for 1 h at this temperature.
1. (a) Irie, M.; Mohri, M. J. Org. Chem. 1988, 53, 803. (b) Irie,
M.; Uchida, K. Bull. Chem. Soc. Jpn. 1998, 73, 985.
(c) Kawai, S. H.; Gilat, S. L.; Lehn, J.-M. Chem. Eur. J.
1995, 1, 285. (d) Tsivgoulis, G. M.; Lehn, J.-M. Chem. Eur.
J. 1996, 2, 1399.
2. Crano, J. C.; Guglielmetti, R. Main Photochromic Families,
Organic Photochromic and Thermochromic Compounds, 1;
Plenum: New York, 1999.