Synthesis and antimicrobial activities of novel 1,2,4-triazolo [3,4-a] phthalazine derivatives.

A series of novel 1,2,4-triazolo [3,4-a] phthalazine derivatives were synthesized in five steps from a common precursor, phthalic anhydride. Most of synthesized phthalazine derivatives showed inhibitory activity against Staphylococcus aureus. One of phthalazine derivatives 5l showed inhibitory activity against all tested bacterial and fungal strains.