Pyridazine and its related compounds. Part 36. Synthesis and antimicrobial activity of some novel pyrimido[4′,5′:4,5]thieno[2,3-c]pyridazine derivatives

Novel derivatives of pyrimidothienopyridazine were designed and synthesized through a versatile method. Some of the target compounds bearing the sulfonamide group were evaluated for their antimicrobial activity against representative Gram-positive bacteria, Gram-negative bacteria, and fungi by applying the agar plate diffusion technique. The results showed that derivatives 11a have promising inhibitory activity against Gram-positive bacteria, and derivatives 11b and 11e have also potent inhibition against fungi. Rest of the compounds showed moderate to low activity against the examined micro-organisms.