One-pot synthesis of naphthopyranopyrimdine derivatives using nano silica phosphoric acid under thermal and solvent-free conditions

Abstract

Nano silica phosphoric acid (nano-SPA) as a recoverable solid catalyst was prepared by the reaction of nano silica chloride with phosphoric acid. The structure of the prepared solid acid was characterized by FESEM, TEM, XRD, FT-IR, BET and EDS mapping techniques. The synthesized nanoparticles were used for one pot synthesis of naphthopyranopyrimdine derivatives via a three component condensation of N,N-dimethylbarbituric acid, aromatic aldehydes and 2-naphthol. This green process has advantages such as short reaction times, simple work-up, easy purification technique, high yields and solvent-free conditions.