Synthesis and chemistry of 4,5-dihydro-6 [2,4-dimethyl phenyl] -3- [2H] pyridazinone azine

Pyridazine derivatives are known to exhibit antiallergic, antihypertensive as well as plant growth regulating effects. In continuation to our previous study in this field we here report the isolation of 4,5-dihydro6-[2,4-dimethyl phenyl]-3-[2H] pyridazinone azine [II a] from the reaction of 6-[2,4-dimethyl phenyl] 4,5-dihydro-pyridazin-3-one [I a] with hydrazine hydrate