Antibacterial and antifungal activities of new pyrazolo[3,4-d]pyridazin derivatives.

Several new pyrazolo[3,4-d]pyridazin derivatives were prepared by the reaction of two [corrected] 1H-pyrazole-3-carboxylic acids and various hydrazines. The compounds were tested for antimicrobial activities against Gram-negative, Gram-positive bacteria and fungi. The compounds named as 7e, f had the highest antimicrobial activities against Gram-negative, Gram-positive bacteria and fungi with minimum inhibitory concentrations in the range of 0.31 to<0.0024 mg ml(-1) .