Ultrasonication-Induced Synthesis and Antimicrobial Evaluation of Some Multifluorinated Pyrazolone Derivatives

A series of novel fluorine containing pyrazole-pyrazolone (4a-j) and chromone-pyrazolone (5a-i) was synthesized from multifluorinated pyrazolone by the Knoevenagel condensation reaction. All compounds were synthesized by conventional heating as well as ultrasound irradiation technique. It was found that ultrasonication method was more efficient than conventional heating method. The newly synthesized compounds were subjected for in vitro antimicrobial screening against four bacterial pathogens, namely, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, and Pseudomonas aeruginosa and three fungal pathogens Candida albicans, Aspergillus niger, and Aspergillus clavatus, using broth microdilution (MIC) method (CLSI guidelines). Among them, some compounds exhibited promising antibacterial activity against the tested strains. All synthesized compounds were characterized by IR, H-1-NMR, mass, and elemental analysis.