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).

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (158 K)Download as PowerPoint slideHighlights► 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.