Microwave-assisted rapid and efficient synthesis of chromene-fused pyrrole derivatives through multicomponent reaction and evaluation of antibacterial activity with molecular docking investigation

The current study aimed to identify a new strategy of FeCl₃ catalyzed multicomponent synthesis of substituted 2H-chromene–fused pyrrole derivatives. A series of chromene-based pyrrole prepared by employing an array of 3-nitro-2H-chromenes, aniline, and acetylacetone in toluene under microwave irradiation. Using FeCl₃ as a prompt catalyst and microwave irradiation to synthesize 2H-chromene–fused pyrrole motifs significantly reduces the reaction time and facilitates to high yields (83%-95%). Structure of all synthesized compounds analyzed by spectroscopic analysis. One-pot reaction, short reaction period, and simple experimental procedure are the fascinating properties associated with this protocol. The in vitro antibacterial activity of the entire series was assessed against Staphylococcus aureus and Escherichia coli. Out of all the compounds, 15b and 15h revealed most excellent potency against both the bacterial strains relative to the reference gentamicin. Docking study was employed to determine the possible binding orientation of DNA gyrase with the active sites of chromene-fused pyrrole analog. The docking results show that compounds 15b and 15h have higher binding affinity with energy −8.00 and −8.80 kcal/mol. These results illuminate the mode of binding progression and provide an esteemed pathway for the design and the structural modification of chromene-fused pyrroles as a newly advanced class of antibacterial agent.