PAPER
HF/BF3-Catalysed Reaction of Substituted Benzenes with CO
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1-Butyl-3-methylimidazolium Tetrafluoroborate [BMIM]BF4
BF4H (48% aq solution; 89.36 g, 0.44 mol) was added dropwise
with stirring to an aq solution of [BMIM]Cl (77.31 g, 0.44 mol, 140
mL) at 0 °C. When the addition of the BF4H was complete, the tem-
perature of the reaction medium was increased to 20 °C and the
mixture left overnight. The ionic liquid was extracted with CH2Cl2
(5 × 80 mL), traces of unreacted BF4H were removed by washing
the organic phase with distilled H2O (10 × 100 mL) and the organic
phase was concentrated in vacuo overnight (120 °C).
References
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of Chemical Technology, 4th ed., Vol. 13; Howe-Grant, M.,
Ed.; John Wiley: New York, 1994, 1030–1042.
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of Industrial Chemistry, 6th ed.; Wiley-VCH: Weinheim,
2002, electronic release.
(4) Imamura, J. Yuki Gusei Kagaku Kyokaishi 1979, 37, 667;
1-Octyl-3-methylimidazolium Tetrafluoroborate [OMIM]BF4
An aq solution of [OMIM]Cl (101.54 g, 0.44 mol, 140 mL) fur-
nished [OMIM]BF4 by a similar procedure to the one described
above.
Chem. Abstr. 1980, 92, 6158.
(5) Degner, D.; Barl, M.; Siegel, H. (BASF, AG) German Patent
DE 2848397, 1980; Chem. Abstr. 1980, 93, 56963.
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1966, 69, 907. (d) Fujiyama, S.; Kasahara, T. Hydrocarbon
Process. 1978, 57, 147.
1-Butyl-3-methylimidazolium Hexafluorophosphate
[BMIM]PF6
To an aq stirred solution of [BMIM]Cl (118.19 g, 0.6773 mol, 150
mL) at 0 °C was added an aq solution of HPF6 (60% solution; 200
mL, 1.5 equiv). The resulting bi-phasic system was stirred for 4 h,
extracted with CH2Cl2 (5 × 80 mL) to remove the ionic liquid, the
organic phase was washed with distilled H2O (10 × 100 mL) to re-
move unreacted acid and the organic phase was concentrated in
vacuo overnight (120 °C).
(7) March, J. Advanced Organic Chemistry, 3rd ed.; John Wiley
& Sons: New York, 1985, 488.
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Compounds; Plenum Press: New York and London, 1991.
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Chemistry Library 8, Roots of Organic Development;
Desmurs, J.-R.; Ratton, S., Eds.; Elsevier: Amsterdam,
1996, 325–335.
(11) Although care should be taken in the handling of the highly
reactive alcohol 16, it could be prepared in almost
quantitative yield via NaBH3 reduction of the corresponding
ketone.
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39, 3772. (b) Holbrey, J. D.; Seddon, K. R. Clean Prod.
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1994, 277.
(14) Sasol Technology R&D, 2001, unpublished results.
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(Mitsubishi Gas Chemical Co.) German Patent DE 2558164,
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L.; Panizo, M. An. R. Soc. Esp. Fis. Quim. 1944, 40, 394.
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Chem. Nat. Compd. (Engl. Transl.) 1990, 26, 232.
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Chem. Eur. J. 2001, 7, 3005.
1-Hexyl-3-methylimidazolium Hexafluorophosphate
[HMIM]PF6
To a stirred solution of [BMIM]Cl (137.31 g, 0.6773 mol) and H2O
(150 mL) at 0 °C was added an aq solution of HPF6 (60% solution;
200 mL, 1.5 equiv) slowly. The resulting bi-phasic system was
stirred for 4 h, extracted with CH2Cl2 (5 × 80 mL), the organic
phase was washed with distilled H2O (10 × 100 mL) to remove the
unreacted acid and the organic phase was concentrated in vacuo
overnight (120 °C).
1-Octyl-3-methylimidazolium Hexafluorophosphate
[OMIM[PF6
An aq solution of [OMIM]Cl (156.30 g, 0.6773 mol) at 0 °C was
added to an aq solution of HPF6 (60% solution; 200 mL, 1.5 equiv),
which furnished [OMIM]PF6 by a similar procedure to the one de-
scribed above.
1-Butyl-3-methylimidazolium Tetrachloroaluminate
[BMIM]AlCl4·0.67(AlCl3)
Freshly sublimed AlCl3 (99.9%; 89.34 g, 0.67 mol) was carefully
added to [BMIM]Cl (57.64 g, 0.33 mol) with stirring under an argon
atmosphere. The resulting ionic liquid was stored under argon.
1-Butyl-3-methylimidazolium Tetrachloroaluminate
[BMIM]AlCl4·75(AlCl3)
Freshly sublimed AlCl3 (99.9%; 100.0 g, 0.75 mol) was carefully
added to [BMIM]Cl (43.67 g, 0.25 mol) with stirring under an ar-
gon atmosphere. The resulting ionic liquid was stored under argon.
1-Ethyl-3-methylimidazolium Tetrachloroaluminate
[EMIM]AlCl4·0.67(AlCl3)
Freshly sublimed AlCl3 (99.9%; 89.34 g, 0.67 mol) was carefully
added to [EMIM]Cl (48.38 g, 0.33 mol) with stirring under an argon
atmosphere. The resulting ionic liquid was stored under argon.
(19) (a) Nystrom, R. F.; Berger, C. R. A. J. Am. Chem. Soc. 1958,
80, 2896. (b) Horning, E. C.; Parker, J. A. J. Am. Chem. Soc.
1952, 74, 3870.
(20) (a) Kauffmann, H.; Pannwitz, P. Chem. Ber. 1912, 45, 771.
(b) Singh, S.; Chhina, S.; Sharma, V. K.; Sachdev, S. J.
Chem. Soc., Chem. Commun. 1982, 453. (c) Baeyer, A.;
Villiger, V. Ber. Dtsch. Chem. Ges. 1902, 35, 1210.
Acknowledgment
The authors would like to express their gratitude to Merisol and Sa-
sol Technology R&D (Pty) Ltd for permission to publish this work.
Synthesis 2006, No. 15, 2543–2550 © Thieme Stuttgart · New York