Preparation, Characterization and Application of Silica-Supported Tungstophosphoric (HPW/SiO₂) Acid Catalyst to the Synthesis of 1, 8-Dioxoacridine Carboxylic Acid Derivatives in Semi Aqueous Condition

An efficient, recyclable silica supported tungstophosphoric acid (HPW/SiO₂) catalyst was prepared by simple stirring method. The catalyst was characterized using FT-IR, X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM) techniques. The catalyst was explored in semi aqueous condition toward synthesis of 1,8-dioxoacridine carboxylic acid derivatives. It was recycled up to four runs and a very marginal loss was detected. The targeted compounds were synthesized in a very short time period and simple work procedure with excellent yield.