Rapid synthesis of 1-amidoalkyl-2-naphthols over sulfonic acid functionalized imidazolium salts

Novel sulfonic acid functionalized imidazolium salts including 3-methyl-1-sulfonic acid imidazolium chloride {[Msim]Cl} (an ionic liquid), 1,3-disulfonic acid imidazolium chloride {[Dsim]Cl} (an ionic liquid) and 3-methyl-1-sulfonic acid imidazolium tetrachloroaluminate {[Msim]AlCl4} (a solid) efficiently catalyze one-pot multi-component condensation of β-naphthol with aromatic aldehydes and amide derivatives under solvent-free conditions to afford 1-amidoalkyl-2-naphthols in excellent yields (81–96%) and in very short reaction times (1–40 min).

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► Introducing two new catalysts (as ionic liquid) for organic transformations.
► Superiority of the catalysts with respect to the reported catalysts.
► Introducing an efficient new method for synthesis of 1-amidoalkyl-2-naphthols.
► Generality of the method, high yields and very short reaction times.
► Application of solvent-free conditions in the reaction.