The Eggshell Waste Transformed Green and Efficient Synthesis of K-Ca(OH)2 Catalyst for Room Temperature Synthesis of Chalcones

We explored the green and eco-friendly synthesis of Ca(OH)2 and K-Ca(OH)2 catalysts from chicken eggshell waste. The highly efficient synthesized catalysts were characterized by means of UV, FTIR, XRD, SEM, and EDS techniques for their optical, structural, morphological, and compositional study, respectively. The potassium impregnated (K-Ca(OH)2) catalyst was synthesized from Ca(OH)2. The K-Ca(OH)2 provides basic nature in reaction solution as compare to Ca(OH)2. The Ca(OH)2 and K-Ca(OH)2 catalysts are efficient, inexpensive, stable and recyclable. Claisen–Schmidt condensation reaction was successfully conducted by using 5 mol% K-Ca(OH)2 at room temperature in combination of ethanol and water solvent. We imparted the green catalytic application of Ca(OH)2 and K-Ca(OH)2 catalysts for synthesis of some chalcones, ranged the yields from 74% to 92% in aqueous ethanol at room temperature. All synthesized chalcone derivatives were confirmed by FTIR and proton NMR spectroscopic techniques.