A highly effective and mild protocol for the production of 1-thioamidoalkyl-2-naphthols using 1,3-disulfonic acid imidazolium trifluoroacetate as a dual-functional catalyst

Abstract

Abstract A solvent-free protocol for the production of 1-thioamidoalkyl-2-naphthols via a one-pot multi-component reaction of arylaldehydes with 2-naphthol and thioacetamide using the ionic liquid 1,3-disulfonic acid imidazolium trifluoroacetate ([Dsim][TFA]) is described. Furthermore, a plausible and attractive mechanism based on the dual functionality of the catalyst is proposed. Because of the dual functionality of [Dsim][TFA] (possessing acidic and basic sites), it is found to be generally highly effective, affording the products in high yields and short reaction times under mild conditions. We claim that this is one of the best protocols for the synthesis of 1-thioamidoalkyl-2-naphthols (in terms of yield, temperature, conditions, and/or the reaction time).