Pyridazines refer to nitrogen-containing six-membered heterocyclic azine compounds, as isomers of pyrimidines and pyrazines respectively. They are insoluble in petroleum ether, but soluble in methanol, ethanol and miscible with water, benzene and dimethylformamide. Pyridazine is a weak base that can form salts with picric acid, hydrochloric acid, etc.
Pyridazine is not prone to nucleophilic and electrophilic aromatic substitution reaction and is very stable under potassium permanganate. It can be converted to 1,4-diaminobutane after the open-chain reduction by sodium and alcohols. Pyridazine is widely used as pharmaceutical raw materials, such as long-term sulfa SMP, a pyridazine derivative, 4-amino-cinnoline as an antimalarial, hydralazine as a hypotensor, etc. , all of which are made from pyridazine; also used as raw material of pesticides such as herbicides,pyramine, ethirimol,brompyrazon, Kusakira,maleic hydrazide,insecticide,Ofunack and so on.