Brönsted acidic ionic liquids: A green, efficient and reusable catalyst system and reaction medium for Fischer esterification

Brönsted acidic ionic liquid containing nitrogen-based organic cations 1-methylimidazole and 1-butyl-3-methylimidazolium and inorganic anions of the type BF4−, PF6− and PTSA− has been synthesized in good yields and used as a catalysts and reaction medium for Fisher esterification of alcohols with acids.