الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The aminopyrazole compounds have been easily obtained by the reaction of nitrile derivatives with hydrazine hydrate, and are very useful as precursors for the synthesis of fused heterocyclic ring systems. The fused heterocyclic compounds play an important role in biological and pharmacological activities, and they can also be used as intermediates in the dyestuff industry. The starting compound 3(5)-amino-5(3)-hydrazinopyrazole dihydrochloride (1) was obtained by the condensation of hydrazine hydrate and malononitrile. In contract to the behavior of malononitrile, arylhydrazono-malononitrile 2 reacts with hydrazine hydrate in hot ethanol to afford the corresponding 3,5-diamino-4-arylazopyrazoles 3. Condensation of 1 with aromatic aldehydes 4 e.g. p-N,N-dimethylaminobenzaldehyde and vanillin gave the corresponding hydrazones 5. The reaction of 1 with 2-acetylferrocene proceeded in hot water containing sodium acetate to furnish the corresponding Schiff base compound 6. The reaction of 3(5)-amino-5(3)-hydrazinopyrazole dihydrochloride (1) with two moles of ninhydrin was carried out in hot water and sodium acetate to afford the corresponding condensation product 7. The formation of fused pyrazol-1’-ylpyrazolopyrimidine derivative 9 was established as refluxing two moles of α-arylhydrazono acetyl acetone 8 with 1 in EtOH : H2O (1:1) or H2O. The reaction of 1 with ethyl α-arylhydrazono acetoacetate 10 was carried out under reflux in EtOH : H2O (1:1) or H2O to give the corresponding pyrazol-1’-ylpyrazolopyrimidine derivative 11. The reaction of 1 with two moles of 3,5-diphenylcyclohex-2-enone was carried out under reflux in ethanol-water mixture to furnish the corresponding condensation product 12.Compounds 3a,b react with arylidenemalononitrile 22 in refluxing ethanol catalyzed by piperidine to yield pyrazolo[1,5-a]pyrimidines 24. The formation of 24 from the reaction of 3 with 22 is assumed to proceed via initial Michael addition of the amino group in 3 to the activated double bond in 22 to yield the corresponding Michael adduct which then cyclizes to give 23, which loses H2 to give 24 .The synthesized compounds 3, 5, 6, 7, 12, 16, 17, 18, 21 and 24 were screened for their antibacterial and antifungal activities.