Synthesis of new s-triazolo[4,3-b] pyridazines

A new synthesis of s-triazolo4,3-b]pyridazine derivatives has been achieved starting from 3,6-dichloropyridazine. The method opens the way to substitutions in the 2- or 3- positions. A tri-cycloderivative, a bis-s-triazolopyridazine, has also been synthesized.