2-Substituted-pyridazin-3(2H)-ones as Green Electrophilic Agents in Synthesis

Pyridazin-3(2H)-ones are inexpensive, stable, and easily prepared heterocycles. Since pyridazin-3(2H)-ones readily form stable anions, and can act as good leaving group. Their utility as synthetic auxiliaries was recently demonstrated by Yoon’s group. 2- Substituted-pyridazin-3(2H)-ones are also useful both the electrophilic agents and equivalents for the functionalization of the electron rich compounds and active methylenes, and synthones. 2-Substituted-pyridazin-3(2H)-ones are novel green agents because that can be recovered quantitatively and recycled. In this review, the preparation and the synthetic application of 2-substituted-pyridazin-3(2H)-ones are described.