Water Extract of Red Mud, a Renewable Aqueous Medium for the Synthesis of Functionalized Xanthene Derivatives via a One-Pot Three-Component Reaction: Mechanistic Studies and Reaction Scope

In this study, an efficient and convenient three-component cyclization protocol is presented for the synthesis of xanthene derivatives using a water extract of red mud (WERM). Red mud is produced in large quantities as waste in aluminum industries, and this is the first report to use WERM as an efficient and renewable medium in the synthesis of xanthenes. We focused our attention on domino condensation/Michael addition/intramolecular cyclization both experimentally and in density functional theory (DFT) studies, where the formation of chromenopyrimidines was suppressed simultaneously. Furthermore, our innovation operates in a straightforward and cost-effective manner, accommodates numerous functional groups, encompasses a broad range of substrates, produces exceptional yields, eliminates the need for column chromatography, enables scalable syntheses, and allows reusability of reaction media, all of which contribute to the principles of green and sustainable chemistry.