The efficient synthesis of carbon–carbon double bonds via Knoevenagel condensation using red mud packed in a column

Red mud (RM) is generated as a by-product during the production of alumina from bauxite ore. In this study, RM packing in a column is used as a catalyst for carbon–carbon double bond formation via Knoevenagel condensation. The reactants are added to the top of the column and then eluted with solvent. The products are collected in high yields and short time. RM packed in a column eliminates a catalyst separation step from the reaction mixture in this work.