Synthesi of 3-Heterocyclic-5,6-diphenylpyridazines

The reactions of 5,6-diphenyl-3-hydrazinopyridazine with different reagents and methods of synthesis of some of pyridazine derivatives, e.g. 3-[pyrazol-1-yl] pyridazines, 1-[pyridazin-3-yl] pyrazolo [3,4-d] pyrimidines, 3-[pyridazin-3-yl] pyridazines, s-triazolo [4,3-b] pyridazines and tetrazolo [1, 5-b] pyridazines were carried out. The structure were confirmed by spectral methods [IR, 1H-NMR, MS]

Synthesis and reactions of 4,6-diaryl-2,3,4,5-tetrahydropyridazin-3-ones

The hitherto unknown 4,6 - diaryl - 2,3,4,5,- tetrahydro - pyridazin - 3-ones III a - e were synthesised from the alpha- aryl, beta-aroylpropionic acids II a-e either by their reaction with hydrazine hydrate or by their conversion to alpha, gamma-diaryl- delta beta, gamma - butenolides [XI], and treatment of the latter with hydrazine hydrate, III afforded 3-chloropyridazin derivative [IV] on its reaction with POCl[3], PCl[5]. The 3-chloropyridazine was treated either with sodium azide producing the tetrazolopyridazine derivative [V] or with acylhydrazines to give the triazolopyridazine derivatives [VI] a-c. 3-Acylpyridazines [VII] a and b were obtained on treatment of III with acetyl chloridies. Ill a was converted to its corresponding thione [VIII], also reacted with benzyl- amine giving 3-N-benzyIpyridazine [IX]. Ill a was dehydrogenated to the corresponding dihydropyridazinone [X]

Synthesis and reactions of 4- [benzyl] -6- [2- [5, 6, 7, 8-tetrahydronaphthyl]] -3 [2H] -one

The present investigation deals with the synthesis and some reactions of 4-benzyl-6-[2-[5,6,7,8-tetrahydronaphthyl]]- pyridazin- 3[2H]-one. Such compound was prepared by base catalysed condensation of benzaldehyde with 6-[2-[5,6,7,8]- tetrahydronaphthyl]] -4, 5-dihydropyridazin-3[2H]-one [1]. The reaction proceeded smoothly to give 4-benzyl-6-[2-[5,6,7,8- tetrahydronaphthyl]]-pyridazin -3[2H]-one [3], via prototropic rearrangement of the intermediate [5,6,7,8-tetrahydronaphthyl]]- pyridazin-3[2H]-one [2]

Acid-base properties of 2,4-dihydroxy benzaldehyde-3 [6-phenyl] pyridazinyl hydrazone [DBP3H] formation constants of some of it's complexes

The objective of this study was to present some details of the synthesis, properties and the analytical behavior of the new reagent; namely, 2,4-dihydroxy-benzaldehyde-3 [6-phenyl] pyridazinyl hydrazone [DBPzH] and its possible applications for the determination and detection of some cations. The finding was based on the evaluation of the dissociation constant of the reagent, the composition and formation constants of the complexes by spectrophotometric and potentiometric methods