Used as an intermediate in the synthesis of pharmaceutical compounds, particularly in the development of nitrogen-containing heterocyclic systems. Its structure allows for functionalization at multiple sites, making it valuable in medicinal chemistry for constructing phthalazine-based bioactive molecules. Commonly employed in research settings to prepare potential enzyme inhibitors or receptor ligands. Also utilized in the preparation of fluorescent probes due to the aromatic and electron-deficient nature of the phthalazine core. Suitable for use in coupling reactions and cyclizations under mild conditions, facilitating rapid library generation in drug discovery.