Synthesis of ion liquid 1-allyl-3-methylimidazolium trifluoromethanesulfonate and application as green solvent on the Friedel-Crafts acylation

Abstract

ZnCl₂ in 1-allyl-3-methylimidazolium trifloromethanesulfonate was found to be a good catalyst for the Friedel-Crafts acylation. The ketone product was isolated easily from the reaction mixture. The reactions were found to proceed smoothly under microwave irradiation. The isolated yield was high with 95% selectivity of pisomer within a few minutes. Moreover, ZnCl2 and ion liquid have been recovered and reused several times without significant loss of catalytic activity.