A green and highly efficient solvent-free synthesis of novel calicx[4]resorcinarene derivatives using tungstate sulfuric acid

Abstract

A facile and simple procedure for the synthesis of novel and known calix[4]resorcinarene derivatives were developed via a reaction of arylaldehydes with resorcinol in the presence of catalytic amounts of tungstate sulfuric acid (TSA) under solvent-free conditions. This eco-friendly method has many appealing attributes, such as excellent yields, short reactions times, use of safe and recoverable catalyst, and simple work-up procedures. TSA was characterized by powdered X-ray diffraction (XRD), X-ray fluorescence (XRF) and FTIR spectroscopy.