β-Cyclodextrin as a supramolecular catalyst for the synthesis of 2H-indazolo[2,1-b]phthalazine-trione derivatives in water and their antimicrobial activities

Abstract

An efficient and green method has been developed for the synthesis of 2H-indazolo[2,1-b]phthalazine-triones derivatives by employing 15 mol% β-cyclodextrinvia a one-pot multicomponent reaction of aldehyde, dimedone, hydrazine hydrate with succinic anhydride/phthalic anhydride in water at 80°C for first time. The catalyst could be recovered and reused for four consecutive cycles without appreciable loss in catalytic activity and evaluated for in vitro antimicrobial activity against different Gram-positive and Gram-negative bacterial strains. The outcome of the screening study showed that compound 6d, 6f and 7n exhibited excellent activity against E. coil. Whereas, compound 6f and 6h exhibited excellent activity against P. aeurginosa, and compound 6c, and 6e displayed again excellent activity against Staphylococcus aureus whereas compound 7o shows excellent activity against S. aureus and B. subtilis when compared with Ampicillin (standard control). The results indicated that maximum compounds are moderately effective against bacterial growth and their effectiveness is highest against standard drugs.