L.V. Snegur et al. / Journal of Organometallic Chemistry 580 (1999) 26–35
33
C5H4), 4.23 (s, 5H, Cp), 4.51 (s, 2H, C5H4), 5.56
(m, 2H, CH2), 6.69, 6.91 (m,1H, CHF), 7.38, 7.80
(m, 4H, Ph). MS, m/z: 416 [M+]. IR spectrum
(KBr pellet, cm−1): 3110, 2935, 2880, 1478, 1440, 1320,
1282, 1218, 1193, 1130, 1056, 914, 876, 836.
chilled to 0–5°C, and a saturated aqueous solution of
26.80 g of ammonium chloride was added. After 5 min
stirring at 0–5°C the organic layer was siphoned off,
washed with cold water (80 ml) to pH 7 and dried by
sodium sulphate. After removal of ether 21.28 g of
yellow needle-shaped crystals of ferrocenylethanol were
obtained in 93% yield. M.p. 74–75°C. Lit. [13] m.p.
73–75°C (after recrystallization from hexane). 1H-
NMR (C6D6, l): 1.31 (d, 3H, CH3); 1.87 (s, 1H, OH);
3.97(t, 2H, C5H4); 4.00 (s, 5H, C5H5); 4.07 (q, 1H,
C5H4), 4.13 (q, 1H, C5H4), 4.50 (m, 1H, CH). IR
spectrum (KBr pellet, cm−1): 3350–3015 (O–H), 1410,
1104, 1000, 810 (ferrocenyl moiety).
3.2.4. 1-Ferrocenylmethyl-2-(i-hydrotetrafluoro-
ethyl)benzimidazole (3)
Compound 3 was prepared from ferrocenylmethanol
(10) and 2-(b-hydrofluoroethyl)benzimidazole (8) ac-
cording to the general procedure. Yield 85%. Rf 0.47
(benzene). Anal.: Found C, 57.65; H, 3.92; F, 17.95; Fe,
13.00; N, 6.51%. Calc. for C20H16F4FeN2: C, 57.72; H,
1
3.87; F, 18.26; Fe, 13.42; N, 6.73%. H-NMR (acetone-
3.2. Synthesis of ferrocenylalkyl polifluoro benzimida-
zoles 1–5
d6): 4.16 (s, 2H, C5H4), 4.28 (s, 5H, Cp), 4.50 (s, 2H,
C5H4), 5.54 (s, 2H, CH2), 6.81, 7.08 (t, 1H, CHF2), 7.42
(m, 2H, Ph), 7.80 (d, 1H, Ph), 7.87 (d, 1H, Ph). IR
spectrum (KBr pellet, cm−1): 3110, 2940, 2870, 1480,
1440, 1340, 1260, 1230, 1217, 1120, 1040, 944, 840,
820.
3.2.1. General procedure
To a mixture of 6.0 mmol of ferrocenylmethanol or
1-ferrocenylethanol and 6.00 mmol of the correspond-
ing polyfluoroalkyl benzimidazoles (6–9) in 6.0 ml of
methylene dichloride, 1.08 ml of 45% aqueous solution
of fluoroboric acid was added with vigorous stirring.
Agitation was continued for 5 min, then 15 ml of
diethyl ether, the same amount of cold water, and 5–10
mg of ascorbic acid were added to the reaction flask.
After vigorous shaking of the mixture the organic
yellow-coloured solution was separated, washed with
cold water (5×15 ml), the solvent was removed and
the residue was dried over calcium chloride.
3.2.5. 1-Ferrocenylmethyl-2-trifluoromethylbenz-
imidazole (4)
Compound 4 was prepared from ferrocenylmethanol
(10) and 2-trifluoromethyl-benzimidazole (9) according
to the general procedure. Yield 96%. Rf 0.32 (hexane/
diethylether 2:1). Anal.: Found C, 59.43; H, 3.87; Fe,
14.18; N, 7.19%. Calc. for C19H15F3FeN2: C, 59.40; H,
3.94; Fe, 14.54; N, 7.29%. 1H-NMR (acetone-d6,
TMS):4.18 (t, 2H, C5H4), 4.27 (s, 5H, Cp), 4.50 (t, 2H,
C5H4), 5.50 (s, 2H, CH2), 7.41 (m, 2H, Ph), 7.82 (m,
2H, Ph). MS, m/z: 384 [M+]. IR spectrum (KBr pellet,
cm−1): 3115, 2940, 2880, 1480, 1432, 1330, 1280,
1240, 1192, 1145, 1125, 1096, 1050,1038, 1010, 958, 930,
840.
3.2.2. 1-Ferrocenylmethyl-2-(trifluoromethoxyfluoro-
methyl)benzimidazole (1)
Prepared from ferrocenylmethanol (10) and 2-(tri-
fluoromethoxyfluoromethyl)benzimidazole (6) accord-
ing to the general procedure. Yield 93%. Rf 0.29 (ben-
zene). M.p. 125–127°C. Anal.: Found C, 56.03; H,
3.72; F, 16.95; N, 6.16%. Calc. for C20H16F4FeN2O: C,
3.2.6. 1-(h-Ethylferrocenyl)-2-(h%-hydrotetrafluoro-
ethyl)benzimidazole (5)
1
56.03; H, 3.73; F, 17.58; N, 6.48%. H-NMR (acetone-
The title compound was prepared as an orange oil
from 1-ferrocenylethanol (11) and 2-(a-hydrote-
trafluoroethyl)benzimidazole (7) according to the gen-
eral procedure. The crystal product was obtained after
recrystallyzation from hexane, yield 73%. M.p. 121–
124°C. Rf 0.26 (hexane/diethylether 2:1). Anal.: Found
C, 58.43; H, 4.23; Fe, 12.96; N, 6.40%. Calc.
for C21H18F4FeN2: C, 58.63; H, 4.22; Fe, 12.98; N,
6.51%. 1H-NMR (acetone-d6, TMS): 1.92-2.06 (m,
3H, CH3), 4.00–4.37 (m, 9H, 2Cp), 4,77 (sbr, 1H,
CH), 6.42–6.94 (m, 1H, CHF), 7.07–7.75 (m, 4H,
Ph). MS, m/z: 430 [M+]. IR spectrum (KBr pellet,
cm−1): 3115, 3000, 2970, 1790, 1675, 1625, 1600,
1525, 1470, 1425, 1395, 1375, 1350, 1340, 1305,
1292, 1215, 1165, 1120, 1080, 1020, 942, 910.
d6, TMS): 4.15 (s, 2H, C5H4), 4.28 (s, 5H, Cp), 4.55(s,
2H, C5H4), 5.50 (s, 2H, CH2), 7.35, 7.75 (m, 4H, Ph),
7.60 (s, 1H, CHF). MS, m/z: 432 [M+]. IR spectrum
(KBr pellet, cm−1): 3108, 3007, 1540, 1479, 1438, 1240,
1191, 1110, 1018, 826.
3.2.3. 1-Ferrocenylmethyl-2-(h-hydrotetrafluoro-
ethyl)benzimidazole (2)
The title compound was prepared from ferrocenyl-
methanol
(10)
and
2-(a-hydrotetrafluoroethyl)
benzimidazole (7) according to the general procedure.
Yield 100%. Rf 0.26 (hexane/diethylether 2:1). Anal.:
Found C, 57.84; H, 4.12; Fe, 13.45; N, 6.37%. Calc.
0
for C20H16F4FeN2: N, 57.72; H, 3.87; Fe, 13.42; N,
6.73%. 1H-NMR (acetone-d6, TMS): 4.16 (s, 2H,