234
M.-G. Shen, C. Cai / Journal of Fluorine Chemistry 128 (2007) 232–235
application of FBS to other reactions, which can promote by
such Lewis acids, is under way in this laboratory.
2-(4-Methoxy-phenyl)-benzimidazole (Lit. [18]). A white
À1
solid; m.p. 225–226 8C. IR (KBr) y 1640 cm
3
(C N),
À1
250 cm (NH). HNMR (DMSO) d 3.52 (3H, m, CH ),
3
1
3
. Experimental
7.20–7.60 (6H, m, Ar), 8.00 – 8.08 (2H, m, Ar), MS (EI) m/z
2
+
24 (M ).
3
.1. General
2-(2-Nitro-phenyl)-benzimidazole (Lit. [20]). Ayellow solid;
À1
À1
m.p. 209–210 8C. IR (KBr) y 1640 cm (C N), 3250 cm
(NH). HNMR (DMSO) d 7.20–7.60(6H, m, Ar), 8.00–8.08 (2H,
1
MPs were obtained with Shimadzu DSC-50 thermal
analyzer. IR spectra were recorded on a Bumem MB154S
1
infra-red analyzer. HNMR spectra were measured on Bruke
+
m, Ar), MS (EI) m/z 239 (M ).
2-(4-Nitro-phenyl)-benzimidazole (Lit. [20]). Ayellow solid;
À1
À1
Advance RX500. MS were recorded with a Saturn 2000 GC/
MS instrument. Inductively coupled plasma (ICP) spectra were
measured on Ultima2C apparatus. Elemental analyses were
performed on a Yanagimoto MT3CHN corder.
m.p. 312–314 8C. IR (KBr) y 1640 cm (C N), 3250 cm
(NH). HNMR (DMSO) d 7.20–7.60(6H, m, Ar), 8.00–8.08 (2H,
1
+
m, Ar), MS (EI) m/z 239 (M ).
2-(2-Hydroxy-phenyl)-benzimidazole (Lit. [21]). A white
À1
solid; m.p. 240–242 8C. IR (KBr) y 1640 cm (C N),
3250 cm (NH). HNMR (DMSO) d 4.60 (1H, d, OH), 7.21–
À1
1
3
.2. Typical procedure for preparation of RE(OPf)3
+
.73 (6H, m, Ar), 8.16–8.22 (2H, m, Ar), MS (EI) m/z 210 (M ).
7
RE(OPf) was prepared according to the literatures [17].
3
2-(4-Methyl-phenyl)-benzimidazole (Lit. [18]). A white
À1
(
Method A). The mixture of PfOH solution (aq) and
solid; m.p. 268–270 8C. IR (KBr) y 1640 cm (C N),
3250 cm (NH). HNMR (DMSO) d 2.60 (3H, m, CH ),
7.20–7.60 (6H, m, Ar), 8.00–8.08 (2H, m, Ar), MS (EI) m/z 208
À1
1
YbCl Á6H O solution (aq) was stirred at room temperature.
3
2
3
(
powder was stirred at boiling temperature. In both methods, the
Method B). The mixture of PfOH solution (aq) and Yb O
2
3
+
(M ).
resulting gelatin-like solid was collected, washed with H O and
2
2-(2-Chloro-phenyl)-benzimidazole (Lit. [20]). Awhite solid;
À1
À1
dried at 150 8C in vacuum to give a white solid, which does not
have a clear melting point up to 500 8C, but shrinks around
m.p. 232–234 8C. IR (KBr) y 1640 cm (C N), 3250 cm
(NH). HNMR (DMSO) d 7.20–7.60(6H, m, Ar), 8.00–8.08 (2H,
1
+
m, Ar), MS (EI) m/z 228.5 (M ).
3
80 8C and 450 8C. IR (KBr) n 1 230 (CF ), 1 150 (CF ), 1 080
3
2
À1
(SO ), 1 060 (SO ), 740 (S–O) and 650 (C–S) cm . ICP:
Calcd. for C O F S Yb: Yb, 10.30%. Found: Yb, 9.88%.
2-(4-Chloro-phenyl)-benzimidazole (Lit. [18]). Awhite solid;
À1
2
2
À1
m.p. 291–293 8C. IR (KBr) y 1640 cm (C N), 3250 cm
(NH). HNMR (DMSO) d 7.20–7.60(6H, m, Ar), 8.00–8.08 (2H,
2
4 9 51 3
1
Anal. calcd. for C O F S YbÁH O: C, 17.21%; H, 0.10%.
2
4
9
51
3
2
+
m, Ar), MS (EI) m/z 228.5 (M ).
Found: C, 17.03%; H, 0.18%.
2
-Furanyl-benzimidazole (Lit. [22]). A white solid; m.p.
À1
À1
3.3. Typical procedure for preparation of benzimidazole
derivatives
285–287 8C. IR (KBr) y 1640 cm (C N), 3250 cm (NH).
HNMR (DMSO) d 6.80–7.00 (3H, m, Furanyl), 7.21–7.43 (4H,
+
m, Ar), MS (EI) m/z 184 (M ).
1
A mixture of Yb(OPf) (67 mg, 0.04 mmol), o-phenylene-
3
diamine (1.08 g, 10 mmol), benzaldehyde (1.17 g, 11 mmol),
toluene (2 mL) and perfluorodecalin (C F , cis and trans-
References
1
0 18
mixture, 1.5 mL). The mixture was stirred at 90 8C for 6 h.
Then, the fluorous layer on the bottom was separated for the
next condensation. The organic solvent in the reaction mixture
[
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3
(
(
organic phase) was removed under reduced pressure and the
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3
(c) T. Roth, M.L. Morningstar, P.L. Boyer, S.H. Hughes, R.W. Buckheit
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CH Cl :MeOH 99:1 as eluent. All products are known
2
2
(
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[
[
1
2
-Phenyl-benzimidazole (Lit. [18]). A white solid; m.p.
À1
(
À1
2
1
90–292 8C. IR (KBr) y 1640 cm (C N), 3250 cm (NH).
HNMR (DMSO) d 7.21–7.73 (7H, m, Ar), 8.16–8.22 (2H, m,
+
Ar), MS (EI) m/z 194 (M ).
chem. Biophys. 197 (1979) 551–559.
3] (a) R.R. Tidwell, J.D. Geratz, O. Dann, G. Volz, D. Zeh, H.J. Loewe, Med.
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(
b) T.A. Fairley, R.R. Tidwell, I. Donkor, N.A. Naiman, K.A. Ohemeng,
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753.
[4] B. George, E.P. Papadopoulos, J. Org. Chem. 42 (1977) 441–443.
2
-Ethyl-benzimidazole (Lit. [19]). A white solid; m.p. 175–
À1
À1
1
1
76 8C. IR (KBr) y 1640 cm
HNMR (DMSO) d 2.30–2.50 (5H, m, C H ), 7.20–7.43 (4H,
+
m, Ar), MS (EI) m/z 146 (M ).
(C N), 3250 cm
(NH).
1
2
5
[
5] H. Fujioka, K. Murai, Y. Ohba, A. Hiramatsu, Y. Kita, Tetrahedron Lett. 46
2005) 2197–2199.
(
2
-Propyl-benzimidazole (Lit. [19]). Awhite solid; m.p. 159–
À1
[
[
6] S. Peddibhotla, J.J. Tepe, Synthesis (2003) 1433–1440.
À1
1
1
61 8C. IR (KBr) y 1640 cm
HNMR (DMSO) d 2.20–2.60 (7H, m, C H ), 7.21–7.43 (4H,
+
m, Ar), MS (EI) m/z 160 (M ).
(C N), 3250 cm
(NH).
7] D.H. Huh, H. Ryu, Y.G. Kim, Tetrahedron 60 (2004) 9857–9862.
3
7
[8] J.M. Mitchell, N.S. Finney, Tetrahedron Lett. 41 (2000) 8431–8434.
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