Microwave-assisted synthesis and antimicrobial evaluation of 6-[3-aryl-1-phenyl-4′,5′-dihydro[4,5′-bi-1H-pyrazol]-3′-yl]-2H-chromen-5-ols

A new series of 6-[3-aryl-1-phenyl-4′,5′-dihydro[4,5′-bi-1 H -pyrazol]-3′- -yl]-2 H -chromen-5-ol derivatives was synthesized by Michael addition of chal­cones 5a – j with hydrazine hydrate in presence of sodium acetate under con­ventional heating and microwave irradiation. Structural assignment of the products was confirmed based on IR, 1H-NMR, 13C-NMR, MS and analytical data. All the synthesized compounds 6a – j were screened for their antimicrobial activity against various bacterial and fungal strains. Most of the compounds exhibited variable range of antimicrobial activity and compounds 6c – f and 6i showed promising antimicrobial potency.