Several phthalazine derivatives were synthesized by the one-pot three-component condensation in good to high yields in the presence of diatomite-SO3H as a solid acid catalyst. Then, a series (n=14) of phthalazine sulfonamides were synthesized by the reaction phthalazine sulfonyl chloride and various amines under solvent-free conditions. The prepared compounds were screened for antibacterial activity against Escherichia coli (E. coli ATCC 25922) and Staphylococcus aureus (S. aureus ATCC 5213) as gram negative and positive respectively. Also, in silico physicochemical parameters of synthesized compounds were studied to predict absorption and permeability using Molinspiration online property calculation server.
