β-Oxo ِAnilides in Heterocyclic Synthesis: Novel Synthesis of Pyridazinones, Pyrazolopyridazines and Cinnolines

Hussein, Abdelhaleem M; El-Gaby, Mohamed; Abushanab, Fathi; Abdel-Raheim, Mohamed; Elapasery, Morsy

doi:10.21608/ejchem.2018.3901.1343

β-Oxo ِAnilides in Heterocyclic Synthesis: Novel Synthesis of Pyridazinones, Pyrazolopyridazines and Cinnolines

Document Type : Original Article

Authors

¹ Department of Chemistry, Faculty of Science, Al Azhar University, Assiut 71524, Egypt

² Dyeing, Printing and Auxiliaries Department, Textile Research Division, National Research Centre, Cairo 12622, Egypt

10.21608/ejchem.2018.3901.1343

Abstract

Compound 1 coupled smoothly with aromatic diazonium salts to yield the corresponding arylhydrazones 2a-d. Compounds 2a-d condensed with DMF-DMA in refluxing xylene to yield the pyridazinones 3a-d. Compounds 3a-d were also established based on its further reaction with some active methylene reagents and some nucleophilic reagents. So, reactions of 3a, b with malononitrile in refluxing ethanolic piperidine afforded arylidinemalononitrile 4a,b. The pyridazinone derivatives 3a, b reacted with hydrazine hydrate to afford the hydrazine derivatives 5a, b. When 3a,b were fused with hydrazine hydrate without solvent, the pyrazolo[4,3-c]-pyridazines 6a,b were obtained. Compounds 6a, b were also obtained when compounds 5a, b melt over melting point for short time. Condensation of 2a, b with ethyl cyanoacetate yield 7a, b. Similarly, reactions of 2a,b with 1 mole of malononitrile afforded the pyridazine derivatives 8a,b. While, when 2 moles of malononitrile reacted with 2a, b in the same experimental conditions to yield the cinnoline derivative (9a, b). Reactions of pyridazine 8a,b with 1 mole of malononitrile afforded 9. Compound 2b was reacted with a mixture of arylidinemalononitrile and acrylonitrile to yield product formulated as triazole moieties 12a, b. Similarly, compound 2b was reacted with a mixture of maleic anhydride and acrylonitrile in the same above experimental conditions to give 13. Also, reactions of 2b with hydroxylamine hydrochloride yield 14.

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