What is "pyridazine"

n. (context organic compound English) A diazine in which the two nitrogen atoms are in the ortho- positions; many of its derivatives are pharmaceuticals, herbicides etc

Pyridazine is a heterocyclic organic compound with the molecular formula (CH)N. It contains a six-membered ring with two adjacent nitrogen atoms, and is aromatic. It is a colorless liquid with a boiling point of 208 °C. It is isomeric with two other (CH)N rings, pyrimidine and pyrazine.