Novel quinoline–imidazolium adducts via the reaction of 2-oxoquinoline-3-carbaldehyde and quinoline-3-carbaldehydes with 1-butyl-3-methylimidazolium chloride [BMIM][Cl]

A library of hydroxyquinolin-3-ylmethylimidazolium adducts were prepared in high yields from the reaction of [BMIM][Cl] with various substituted quinoline-3-carbaldehydes and 2-oxoquinoline-3-carbaldehydes under mild conditions by using sodium acetate in MeCN under ultrasound irradiation. The use of sodium acetate and imidazolium chloride was crucial for the success of these CC bond forming reactions. Attempted coupling with thiazolium bromide led instead to quinoline-3-carboxylic acid.