6856
J.-M. Becht et al. / Tetrahedron 60 (2004) 6853–6857
3.2.6. 2-(2-Bromophenyl)thiophene (2f). n-Butyllithium
(1.6 M solution in hexane, 5.62 mL, 9.0 mmol, 3 equiv.) is
added dropwise at 240 8C under an atmosphere of argon to
a solution of thiophene (0.72 mL, 9.0 mmol, 3 equiv.) in
anhydrous THF (7 mL). The reaction mixture is stirred
for 1 h at 220 8C. Then, 1,2-dibromobenzene (0.36 mL,
3.0 mmol, 1 equiv.) is added dropwise at 220 8C. The
reaction mixture is warmed to rt during 15 h, then quenched
by addition of H2O (10 mL). The aqueous layer is extracted
twice with Et2O (total 30 mL) and the combined organic
layers are dried over MgSO4, filtered under vacuum and
concentrated under reduced pressure. The residue is purified
by flash silica gel chromatography (hexane) to yield 2f as a
colorless oil in 91% yield (653 mg). 1H NMR (CDCl3,
200 MHz): d 7.09–7.59 (m, 6H), 7.72 (dd, J¼8.1, 1.2 Hz,
1H). 13C NMR (CDCl3, 75 MHz): d 122.7, 125.9,
126.8, 127.3, 127.6, 128.8, 131.8, 133.5, 135.1, 141.5. IR
(CH2Cl2): 3054, 1558, 1468, 1432, 1261, 1029, 851, 755,
703. MS: [MþH]þ¼240. Elemental analysis calcd (%) for
C10H7BrS (239.13): C 50.23, H 2.95, Br 33.41, S 13.41;
found C 50.37, H 2.93, S 13.24.
132.9, 138.2, 141.8. IR (CH2Cl2): 3054, 2941, 1600, 1561,
1470, 1421, 1390, 1282, 1225, 1176, 1026, 980, 931,
758. [MþH]þ¼238. Elemental analysis calcd (%) for
C10H9BrN2 (237.10): C 50.66, H 3.83, Br 33.70, N 11.82;
found C 50.79, H 3.85, N 11.71.
Acknowledgements
`
This work was supported by the Ministere de l’Education
Nationale, de la Recherche et de la Technologie through a
MENRT grant to J. -M. Becht.
References and notes
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3.2.7. 2-(2-Bromophenyl)furan (2g). n-Butyllithium
(1.6 M solution in hexane, 5.19 mL, 8.3 mmol, 2.8 equiv.)
is added dropwise at 210 8C under an atmosphere of argon
to a solution of furan (0.65 mL, 9.0 mmol, 3 equiv.) in
anhydrous THF (9 mL). The reaction mixture is stirred
for 3 h at 210 8C. Then, 1,2-dibromobenzene (0.36 mL,
3.0 mmol, 1 equiv.) is added dropwise at 0 8C. The reaction
mixture is warmed to rt during 3 h, then quenched by
addition of H2O (10 mL). The aqueous layer is extracted
twice with Et2O (total 30 mL) and the combined organic
layers are dried over MgSO4, filtered under vacuum and
concentrated under reduced pressure. The residue is purified
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colorless oil in 54% yield (361 mg). 1H NMR (CDCl3,
200 MHz): d 6.57 (dd, J¼3.4, 1.9 Hz, 1H), 7.05–7.75 (m,
5H), 7.82 (dd, J¼7.8, 1.7 Hz, 1H). 13C NMR (CDCl3,
75 MHz): d 110.5, 111.4, 119.6, 127.3, 128.3, 128.7, 131.2,
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O 7.14.
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