2-Arylhydrazononitriles as building blocks in heterocyclic synthesis: A novel route to 2-substituted-1,2,3-triazoles and 1,2,3-triazolo[4,5-b]pyridines

2-Arylhydrazono-3-oxobutanenitriles 2 was reacted with hydroxylamine hydrochloride to yield amidooxime 3. This was cyclized into the corresponding oxadiazole 4 on refluxing in acetic anhydride. When refluxed in DMF in presence of piperidine, the corresponding 1,2,3-triazoleamine 5 was formed. The latter was acylated to 6 by addition of acetic anhydride while treatment of 5 with malononitrile gave the 1,2,3-triazolo [4,5-b]pyridine 8. Treatment of acetyl derivative 6 with DMFDMA gave enaminone 9. The enaminone 9 was coupled with benzenediazonium chloride to yield phenylazo-1,2,3-triazolo [4,5-b]pyridine 10. Trials to convert compound 14 into 1,2,3-triazolo [4,5-d]pyrimidine 15 via refluxing in AcOH/NH(4)OAc failed. Instead the hydrolyzed product 5 was formed

with Active Methylene Reagents: Formation of 2-Hydroxyand 2-Amino-6-substituted-5-arylazonicotinates and Pyrido[3,2-c]cinnolines via 6π-Electrocyclization Reactions

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On the reaction of phenacylmalononitrile with hydrazines: A new route to pyrazolo[3,4-c]pyridazine, isoxazolo[5,4-c]pyridazine and pyrimido[4,5-c]pyridazine

AbstractThe reaction of arylmalononitiles 1a,b with hydrazine hydrate at room temperature has afforded 3-oxo-6-aryl-2,3,4,5-tetrahydropyridazine-4-carbonitrile 3a,b as the sole isolable product. These 3-oxopyridazin-4-carbonitriles underwent aromatization to 3-oxo-6-phenylpyridazine-4-carbonitrile 4 on attempted coupling with benzene diazonium chloride. Compound 3a reacted with hydrazine hydrate as well as urea to yield pyrazolo[3,4-c]pyridazine 5 and pyrimido[4,5-c]pyridazine 6. On the other hand, amidoximes 7a,b were isolated from reaction of 3a,b with hydroxylamine hydrochloride. Amidoximes 7a could be cyclized successfully into 5-phenylisoxazolo[5,4-c]pyridazin-3-amine 8 while 7b could not be cyclized on our hand

Article A Facile Synthesis of Arylazonicotinates for Dyeing Polyester Fabrics under Microwave Irradiation and Their Biological Activity Profiles

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Polyfunctional nitriles in organic syntheses: A novel route to aminopyrroles, pyridazines and pyrazolo[3,4-c]pyridazines

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