One-pot Synthesis of Indenonaphthopyrans Catalyzed by Copper(II) Triflate: A Comparative Study of Reflux and Ultrasound Methods

Abstract

An effective and environment-friendly protocol for the synthesis of indenonaphthapyranes has been developed by one-pot reaction of 2-naphthol; various aromatic aldehydes; and 1,3-indandione, in the presence of copper(II) triflate as catalyst, while using reflux (Method A) and ultrasound (Method B). The Method B approach offers the advantages of reaction, a simple method, short reaction time, excellent yield, and the economic importance of the catalyst or processes.