Several new pyrazolo [3, 4-d] pyridazin derivatives were prepared by the reaction of two new 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 ...
