Synthesis of fluorescent hydroxyl naphthalene-1,4-dione derivatives by a three-component reaction in water

Abstract

An efficient one-pot synthesis of fluorescent hydroxyl naphthalene-1,4-dione derivatives by a simple, atom-economical and three-component reaction of 2- hydroxynaphthalene-1,4-dione, aromatic aldehydes and heterocyclic or carbocyclic amines in the presence of a catalytic amount of InCl 3 in refluxing water is reported. The structures of the compounds were confirmed by IR, 1H NMR, 13C NMR, and elemental analysis. UV- visible absorption coefficient, maximum wavelength and fluorescence emission wavelength were measured in methanol. The products were fluorescent in solution emitting at green light (546–560 nm). The advantages of this procedure are mild reaction conditions, high yields of products, operational simplicity and easy work-up procedures. The workup of these very clean reactions involves only a filtration and simple washing step with EtOH.