Vol 8, No 3 (2018)

Nitrogen atom containing heterocycles showed diverse biological properties are important structural feature of many physiologically active compounds. Pyridazines and phthalazines hold considerable interest relative to the preparation of physiologically active compounds. The pyridazine compounds also show antifeeedant, insecticidal, herbicidal, molluscicidal, plant growth regulatory and other agrochemical activities. The various pyridazine drugs are selective PDE-III inhibitors possessed positive inotropic effect combined with vasodilation. These agents are effective in different cardiovascular diseases like acute and chronic heart failure, myocardial infarction, angina, arrhythmia, and hypertension. Pyridazines and phthalazines further focus our attention because of their easy functionalization at various ring positions, which makes them attractive synthetic compounds for designing and development of the novel pyridazines and phthalazines drugs in future. Various substituted pyridazine derivatives were also reported to show antibacterial, antifungal, and antiviral properties. We considered some compounds bearing pyridazine in their molecular framework.