BackgroundSome novel substituted pyrazolone, pyrazolo[3,4-c]pyridazine, pyrazolo[3,4-d]pyrimidine, pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidinone, thieno[3,2-c]pyrazole and pyrazolo[3′,4′:4,5]thieno[2,3-d]pyrimidine derivatives have been reported to possess various pharmacological activities like antimicrobial, antitumor and anti-inflammatory.ResultsA novel series of azoles and azines were designed and prepared via reaction of 1,3-diphenyl-1H-pyrazol-5(4H)-one with some electrophilic and nucleophilic reagents. The structures of target compounds were confirmed by elemental analyses and spectral data.ConclusionsThe antimicrobial activity of the target synthesized compounds were tested against various microorganisms such as Escherichia coli; Bacillus megaterium; Bacillus subtilis (Bacterial species), Fusarium proliferatum; Trichoderma harzianum; Aspergillus niger (fungal species) by the disc diffusion method. In general, the novel synthesized compounds showed a good antimicrobial activity against the previously mentioned microorganisms.

No abstract

The chemical reactivity of diketone 1 toward some nucleophilic and electrophilic reagents was investigated. diketone 1 was used as a key precursor for the synthesis of many important heterocyclic compounds. The synthesized compounds were characterized by IR, 1H-NMR, MS spectral and elemental analysis.

Abstract2-Aminopyridine was fused with ethyl acetoacetate for two hours to yield the N-2-pyridyl-3-oxobutanamide (1). However, when the reaction time was increased to 5 hours compound 3 was obtained. Condensation of 3 with benzaldehyde gave 4. The reaction of pyridopyridone 3 with arylidenemalononitrile 7a-c afforded 4H-pyran derivatives 10a-c. In contrast to the behavior of arylidenemalononitriles 7a-c towards pyridopyridine 3, benzylidenemalononitrile 7d reacted with compound 3 to give the product 11. Compound 1 was allowed to react with arylidenemalononitriles to give the dihydropyridine derivatives 17a-d. Alkylation of compound 1 with alkylating agents has been also reported. Thus, compound 1 was condensed with [DMF-DMA] in refluxing dioxane to yield 18, but under the reaction conditions we obtained only 21. The pyridopyridone 3 reacted with benzoyl isothiocyanates 25a,b to give thiourea derivatives 26a,b. Cyclization of 26a,b in dry dioxane and conc. sulphuric acid afforded pyridopyrimidine-2-thione derivatives 27a,b. On the other hand, coupling of pyridopyridone 3 with the aryl diazonium salts 28a-e afforded the corresponding azo products 29a-e. Boiling of compound 29 in ethanol and HCl afforded the azo products 30a-e. Treatment of arylhydrazone 30a with malononitrile afforded the pyridazine derivative 31.