A mixture of 20.0 g of 3-hydrazino-4-methyl-6-piperidinopyridazine in 100 ml
of aqueous 99% formic acid was heated at the boiling temperature under
reflux for 3 h and then evaporated to dryness. The residue, containing 8-
methyl-6-piperidino-s-triazolo[4,3-b]pyridazine formate was taken up in
excess aqueous sodium carbonate and extracted with chloroform. After
evaporation of the chloroform solvent the 8-methyl-6-piperidino-s-
triazolo[4,3-b]pyridazine was crystallized from ethyl acetate. Yield 4.4 g,
melting point 118-120°C.
