Development of chalcone synthesis: Optimization of synthetic method

Flavonoids have been developed as the main molecular model of medical and industrial applications through the years. Chalcones (1,3-diphenyl-2-propen-1-one) are biological compounds and biogenetic precursors of flavonoids and isoflavonoids abundant in plants. Moreover, chalcone is the main precursor in the synthesis of various heterocyclic compounds. The broad utilization of chalcone encourages research on chalcone synthesis development to be carried out to improve the reaction quality. Therefore it is essential to develop highly efficient strategies in chalcone synthesis. This research aims to optimize the methods of chalcone synthesis. In this research, chalcone was synthesized through a Claisen-Schmidt condensation by reacting acetophenone and benzaldehyde with KOH as a base catalyst using reflux and grinding. Ethanol is used as a solvent in the reflux method, while the reaction was carried out neatly in the grinding process. Furthermore, chalcone was purified through the recrystallization and its purity test by thin-layer chromatography and melting point. All of the obtained chalcones were characterized using UV-Vis spectroscopy. In previous studies, synthesis chalcone derivative using grinding process gave a higher yield 74-80% than the reflux method. From this research, the reflux method gave a 9.2% yield while the grinding process yielded 32.6% product. It could be concluded that the grinding techniques could provide a higher result than the reflux method. It also could be chosen as a green synthesis method as it uses less solvent, shorter reaction time, and ambient temperature.