One-Pot Synthesis of Phthalazines and Pyridazino-aromatics: A Novel Strategy for Substituted Naphthalenes.

A new one-pot strategy for the synthesis of phthalazines and pyridazino-aromatics starting from aromatic aldehydes has been developed. A variety of substituents ranging from electron withdrawing to donating is tolerated furnishing the desired 1,2-diazine in good to excellent yields. The products have been applied to the bidentate Lewis acid catalyzed inverse electron-demand Diels–Alder (IEDDA) reaction opening a novel two-step entry into substituted naphthalenes, such as Naproxen. [ABSTRACT FROM AUTHOR]