Pyridazine Chemistry in Crop Protection

An overview is given of the significance of the pyridazine scaffold in crop protection chemistry. The main herbicidally, fungicidally, and insecticidally active pyridazine classes are presented, together with their synthesis routes, modes of action, and biological efficacies. In addition, the role of pyridazines as an isosteric replacement or as lead structure of other agrochemicals is reported. Also, benzannulated pyridazines, such as cinnolines and phthalazines as well as partially and fully saturated pyridazine derivatives, are covered.