Synthesis and Biological Evaluation of Bicyclic Pyrazolines with Promising Antimicrobial Activities

The efficient photochemical synthesis of bicyclic pyrazolines using flow technology as well as the subsequent antimicrobial evaluation of these scaffolds is reported. Low minimal inhibitory concentration values of 0.5-4 μg mL^-1 are found against a series of multidrug resistant bacterial strains including different Staphylococcus and Enterococcus genera species. The lead compound, which is decorated by a halogenated aryl ring system, appears to be bacteriostatic and shows excellent physicochemical and pharmacokinetic properties. Due to low levels of predicted toxicity combined with a high level of drug-likeness, these bicyclic pyrazolines therefore are promising candidates for further studies as antibacterial species.