Syntezy i aktywność biologiczna pochodnych pirydopirydazyny

For many years all six isomers of pyridopyridazines have been an interesting class of heterocyclic compounds because of their biological and chemical properties. Endralazine is a hypotensive drug, which contain pyrido[4,3-c]pyridazine structure. Presented in this paper selected compounds exhibit antiviral [20] and antibacterial [21, 22] activity. Based on review of the chemical literature, derivatives of pyridopyridazine showed a multipharmacological effects such as analgesic [23–29] and diuretic [33–38] activity. Some chemical compounds, containing pyridopyridazine moiety showed anticancer activity in vitro with different mechanism of action [12, 15, 18, 19]. Novel pyrazolopyridopyridazine derivatives have been identified as more potent and selective phosphodiesterase 5 (PDE5) inhibitors than sildenafil [41]. Pyrido[2,3-d] pyridazine derivatives were synthesized as selective PDE4 inhibitors [44–46], with good selectivity profile and less undesiderable side effects. 2,3,8-Trisubstituted pyrido[ 2,3-d]pyridazines were novel classes of GABA-A receptor benzodiazepine binding site ligands [30, 31]. While pyrido[2,3-c]pyridazine derivatives were selective agonists for the benzodiazepine site of GABA-A receptor [32]. Some of new substituted pyrido[3,2-c]pyridazine derivatives possess molluscicidal activity [54] and can be used as biodegradable agrochemicals.