Ionic liquid mediated esterification of alcohol with acetic acid

Abstract

Highly efficient esterification of alcohols with acetic acid by using a Brønsted acidic ionic liquid, i.e., 1-methyl-2-pyrrolidonium hydrogen sulfate ([Hnmp]HSO₄), as catalyst has been realized. The turnover numbers (TON) were able to reach up to 11000 and turnover frequency (TOF) was 846. The catalytic system is suitable for the esterification of long chain aliphatic alcohols, benzyl alcohol and cyclohexanol with good yields of esters. The procedure of separating the product and catalyst is simple, and the catalyst could be reused. [Hnmp]HSO₄ had much weaker corrosiveness than H₂SO₄. The corrosive rate of H₂SO₄ was 400 times more than that of [Hnmp]HSO₄ to stainless steel.

Keywords

ionic liquid / Brønsted acid / esterification / catalyst

References

[1] Larock R C. Comprehensive Organic Transformations. New York: John Wiley and Sons Inc, 1999

[2] Forbes D C, Weaver K J. Brønsted acidic ionic liquids: the dependence on water of the Fischer esterification of acetic acid and ethanol. J Mol Catal A: Chem, 2004, 214: 129-132

[3] Welton T. Room-temperature ionic liquids: solvents for synthesis and catalysis. Chem Rev, 1999, 99: 2071-2083

[4] Wasserscheid P, Welton T, eds. Ionic Liquids in Synthesis. Weinheim: Wiley-VCH, 2003

[5] Sheldon R. Catalytic reactions in ionic liquids. Chem Commun, 2001, 2399-2407

[6] Holbrey J D, Seddon K R. Ionic liquid. Clean Prod Process, 1999, 1: 223-236

[7] Zhang S J, Lv X M. Ionic liquid-from foundational research to industrial application. Beijing: Science Publication, 2006

[8] Judeh Z M A, Shen H Y, Chi B C, Feng L C, Selvasothi S. A facile and efficient nucleophilic displacement reaction at room temperature in ionic liquids. Tetrahedron Lett, 2002, 43: 9381-9384

[9] Deng Y Q, Shi F, Beng J J, Qiao K. Ionic liquid as a green catalytic reaction medium for esterifications. J Mol Catal A: Chem, 2001,165: 33-36

[10] Cole A C, Jensen J L, Ntai I, Tran K L T, Weaver K J, Forbes D C, Davis J H, Novel Brønsted acidic ionic liquids and their use as dual solvent-catalysts. J Am Chem Soc, 2002, 124: 5962-5963

[11] Zhu H P, Yang F, Tang J, He M Y. Brønsted acidic ionic liquid 1-methylimidazolium tetrafluoroborate: a green catalyst and recyclable medium for esterification. Green Chem, 2003, 5: 38-39

[12] Gui J Z, Cong X H, Liu D, Zhang X, Hu Z, Sun Z. Novel Brønsted acidic ionic liquid as efficient and reusable catalyst system for esterification. Catal Commun, 2004, 5: 473-477

RIGHTS & PERMISSIONS

Higher Education Press and Springer-Verlag Berlin Heidelberg