1
050
J. S. Yada6 et al. / Tetrahedron Letters 44 (2003) 1047–1050
4. (a) Deyrup, J. A.; Moher, C. L. J. Org. Chem. 1969, 34, Recycling of ionic liquid: In the case of the hydrophilic
1
75; (b) Crooks, P. A.; Szyudler, R. Chem. Ind. (London)
ionic liquid, i.e. [bmim]BF , the reaction mixture was
4
1
973, 1111.
diluted water and extracted with ethyl acetate (2×10 mL).
The combined organic extracts were washed with water,
dried over anhydrous Na SO and concentrated in vacuo
and the resulting product was purified either by column
chromatography or by recrystallization to afford pure
product. The ionic liquid can be recovered either by
extracting the aqueous phase with ethyl acetate or by
evaporating the aqueous layer in vacuo. The ionic liquid
thus obtained was further dried at 80°C under reduced
pressure for use in subsequent runs.
5
. (a) Meguro, M.; Asao, N.; Yamamoto, Y. J. Chem. Soc.,
Perkin Trans. 1 1994, 2597; (b) Chini, M.; Crotti, P.;
Favero, L.; Macchia, F.; Pineschi, M. Tetrahedron Lett.
2
4
1
1
994, 35, 433; (c) Auge, J.; Leroy, F. Tetrahedron Lett.
996, 37, 7715.
6
. (a) Sekar, G.; Singh, V. K. J. Org. Chem. 1999, 64, 287;
b) Rampalli, S.; Chaudhari, S. S.; Akamanchi, K. G.
(
Synthesis 2000, 78.
7
. (a) Das, U.; Crousse, V.; Kesavsn, V.; Daniele, B. D.;
Begue, J. P. J. Org. Chem. 2000, 65, 6749; (b) Curini, M.;
Epifano, F.; Marcotullio, M. C.; Rosati, O. Eur. J. Org.
Chem. 2001, 4149; (c) Harrak, Y.; Pujol, M. D. Tetra-
hedron Lett. 2002, 43, 819.
. Yamada, J.; Yumoto, Y.; Yamamoto, Y. Tetrahedron
Lett. 1989, 30, 4255.
. (a) Welton, T. Chem. Rev. 1999, 99, 2071; (b) Wasser-
scheid, P.; Keim, W. Angew. Chem., Int. Ed. 2000, 39,
3
Spectral data for selected products:
2
3
3
-Phenylamino-2-phenyl ethanol (2a): Liquid; IR (neat): w
1
328, 2925, 1542, 1233, 1041, 760; H NMR (CDCl ): l
3
.75 (dd, 1H, J=6.9, 10.9 Hz), 3.95 (dd, 1H, J=3.9, 10.9
8
9
Hz), 4.50 (dd, 1H, J=6.9, 10.9 Hz), 6.50 (d, 2H, J=8.0
Hz), 6.70 (t, 1H, J=7.8 Hz), 7.10 (t, 2H, J=7.9 Hz)
+
7
.30–7.40 (m, 5H); EIMS m/z: 213 M , 195, 107, 91, 77,
57.
772.
trans-2-(Phenylamino)cyclohexanol (4d): Solid; mp 60–
1
1
0. (a) Sheldon, R. J. Chem. Soc., Chem. Commun. 2001,
6
1
1
2
3
7
4
1
1°C; IR (KBr): w 3073, 2960, 1547, 1449, 1375, 1263,
2
5
399; (b) Peng, J.; Deng, Y. Tetrahedron Lett. 2001, 42,
917.
1
042, 974, 702; H NMR (CDCl ): l 1.0–1.2 (m, 1H),
3
.30–1.45 (m, 3H), 1.70–1.90 (m, 2H), 2.10–2.20 (m, 2H),
.80 (brs, NH, 1H), 3.15 (ddd, 1H, J=10.5, 9.5, 4.0 Hz),
.30 (ddd, 1H, J=9.8, 9.8, 4.5 Hz), 6.70–6.80 (m, 3H),
1. (a) Park, S.; Kazlauskas, R. J. J. Org. Chem. 2001, 66,
395; (b) Bonhote, P.; Dias, A. P.; Papageorgiou, N.;
Kalyanasundaram, K.; Gratzel, M. Inorg. Chem. 1996,
5, 1168.
8
+
.15–7.25 (m, 2H); EIMS m/z: 191 M , 174, 99, 82, 77,
3
1.
1
2. General procedure: A mixture of epoxide (1 mmol), aryl
1
-(Phenylamino)-3-phenoxy-2-propanol (3f): Liquid;
H
amine (1 mmol), in [bmim]BF or [bmim]PF (1 mL) was
4
6
NMR (CDCl ): l 3.10 (dd, 1H, J=7.0, 12.5 Hz), 3.25
3
stirred at ambient temperature for the appropriate time
see Table 1). After completion of the reaction, as indi-
(
(
dd, 1H, J=4.0, 12.5 Hz), 3.40–3.55 (m, 2H), 3.95–4.0
(
m, 1H), 6.50–6.70 (m, 3H), 7.10–7.40 (m, 7H); EIMS
cated by TLC, the reaction mixture was washed with
diethyl ether (3×10 mL). The combined ether extracts
were concentrated in vacuo and the resulting product was
directly charged on to a small silica gel column and
eluted with a mixture of ethyl acetate:n-hexane (1:9) to
afford pure b-amino alcohol. The rest of the viscous ionic
liquid was further washed with ether and dried at 80°C
under reduced pressure to retain its activity in subsequent
runs.
+
m/z: 243 M , 225, 134, 121, 108, 91, 77, 45.
1
-(4-Methylphenylamino)hexan-2-ol (3k): Liquid; IR
1
(
neat): w 3027, 2929, 1549, 1447, 1269, 964, 754; H NMR
CDCl ): l 0.95 (t, 3H, J=6.8 Hz), 1.25–1.60 (m, 6H),
(
3
2.20 (s, 3H), 2.95 (dd, 1H, J=8.5, 12.5 Hz), 3.25 (dd, 1H,
J=3.5, 12.5 Hz), 3.80 (m, 1H), 6.60 (d, 2H, J=8.0 Hz),
+
6.90 (d, 2H, J=8.0 Hz); EIMS m/z: 207 M , 190, 178,
135, 121, 107, 91, 84, 57.