An expedient and straightforward solvent‐free synthesis of 1,8‐dioxo‐octahydroxanthenes using eco‐friendly aluminized polyborate catalyst
Dilip Aute, Akshay Kshirsagar, Bhagwat K. Uphade, Anil Gadhave
Abstract
Abstract The present work deals with a catalytic application of aluminized polyborate as a mild solid acid catalyst for multicomponent synthesis of 1,8‐dioxo‐octahydroxanthenes under solvent‐free condition at 100°C‐110°C. It involves selective domino Knoevenagel‐Michael reaction of 1 mole of aromatic aldehyde with 2 moles dimedone. The aluminized polyborate is simply synthesized by using boric acid and aluminum trichloride and characterized by FT‐IR, XRD, SEM and EDAX techniques. The mild Lewis acidity, crystalline solid nature, stability and recyclability are significant features of the catalyst. The solvent‐free condition, clean reaction profile, inexpensive and non‐toxic catalyst, operational simplicity, good to excellent product yields, reduced reaction time and applicability to wide range of substrate are crucial features of this protocol.