Nitrogen atom containing heterocyclic compounds, pyridazines, pyridazinones and phthalazines are important structural feature of many biologically active compounds and show diverse pharmacological properties. Pyridazines and phthalazines hold considerable interest relative to the preparation of organic intermediates and physiologically active compounds. On the basis of literature, pyridazines, pyridazinone and phthalazines further focus our attention because of their easy fictionalization at various ring positions, which makes them attractive synthetic compounds for designing and development of the novel pyridazines and phthalazines drugs in future.