Abstract
Pyridazine and pyridazinone are heterocycles that contain two adjacent nitrogen atoms and shown wide range of pharmacological activities such as antimicrobial, antidepressant anti-hypertensive, anticancer, antiplatelet, antiulcer, herbicidal, antifeedant and various other anticipated biological activities. Pyridazine ring are present in some commercially available drugs and agrochemicals. Pyridazine based systems have been shown to have numerous practical applications.