Amberlyst-15: An Efficient and Reusable Catalyst for One Pot Synthesis of Pyrazoline Derivatives Bearing an Indole Moiety as New Antimicrobial Agents

摘要

Heterogeneous Amberlyst-15 catalyst exhibit an efficient catalytic properties for the cyclization of 1-(4-Fluoro-phenyl)-3-(1H-indol-3-yl)-propenone (chalcones) with various aryl/alkyl hydrazines under microwave irradiation to yield 3-[5-(4-Fluoro-phenyl)-4,5-dihydro-1H-pyrazol-3-yl]-1H-indole derivatives (3a-3j). The newly synthesized compounds were evaluated for their antimicrobial activity against gram-positive bacteria (Salmonella abony and Pseudomonas aeruginosa) and gram negative bacteria (Escherichia coli and Klebsiella pneumonia) by using disc diffusion method. The results reveal that the current synthetic pathway provides many advantages, such as commercially available inexpensive starting materials and recyclable catalyst, ecofriendly reaction conditions, shorter reaction time with excellent yields and all the synthesized compounds are reflecting worthy biological activity.