Pyridazine and pyridazinone compounds in crops protection: a review

Pyridazine and pyridazinone belong to the same group of six-membered heterocyclic compounds, and both structurally feature two adjacent nitrogen atoms. Pyridazine and pyridazinone derivatives are frequently used as core structures in the development of new green agrochemicals due to their high activity and environmental friendliness, attracting significant attention from researchers in recent years. Over the past 20 years, significant developments have occurred in the field of pyridazine and pyridazinone derivatives, which exhibit insecticidal, fungicidal, herbicidal, antiviral, and plant growth regulating activities. Hence, summarizing the process of creating novel molecules with pyridazine and pyridazinone structures through design concepts, understanding structure–activity relationships, and mechanisms of action is an important undertaking. This review aims to provide a comprehensive overview of these advancements, shedding light on the discovery and mechanism of action of novel pesticides in the pyridazine and pyridazinone categories.