Ultrasound-Assisted Syntheses of Some Derivatives Chalcones and Their Potential Antibacterial Activity

Three chalcone derivatives have been synthesized via Claisen-Schmidt condensation by reacting 4-methyl acetophenone and three benzaldehyde derivatives (4-chloro benzaldehyde, 4-methoxy benzaldehyde, and 4-methyl benzaldehyde) under ultrasonic irradiation and conventional method. The synthesized compound structure was confirmed by FTIR, 1H-NMR, and 13C-NMR, confirming that the synthesized chalcones were 4-chloro-4'-methyl chalcone, 4-methoxy-4'-methyl chalcone, and 4-methyl-4'-methyl chalcone (Yield 76.7-90.4%). Chalcone synthesis using ultrasonic irradiation was more effective than conventional methods because the reaction time was shorter, the energy consumption was lower, the synthesis process was more straightforward, and a higher yield was obtained. Antibacterial activity was determined using an agar disk diffusion test against Staphylococcus aureus and Escherichia coli. The results showed that the three synthesized chalcones inhibited E. coli more strongly than S. aureus. 4-methoxy-4'-methyl chalcone showed more activity against E coli than the other chalcones. Meanwhile, 4-chloro-4'-methyl chalcone has more potent antibacterial activity against S aureus.