Utility of N-2-pyridyl-3-oxobutanamide in heterocyclic synthesis: Synthesis of new dihydropyridine, fused pyridine, pyridopyridine, pyridazine and pyridopyrimidinethione derivatives
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引用次数: 0
Abstract
2-Aminopyridine was fused with ethyl acetoacetate without solvent for two hours to yield the N-2-pyridyl–3-oxobutanamide 1. However, when the reaction time was increased to 5 hours a structure 3 was obtained. Condensation of the structure 3 with benzaldehyde gave 4. The reaction of pyridopyridone 3 with arylidenemalononitrile7a-c afforded 4 H-pyran derivative 10a-c. In contrast to the behavior of arylidenemalononitrile 7a-c towards pyridopyridine3, benzylidenemalononitrile 7d reacted withcompound 3 to give a product 11. Compound 1 was allowed to react with arylidenemalononitrile to give the dihydropyridine derivative 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 benzoylisothiocyanate 25a,b to give thiourea derivatives 26a,b Cyclization of 26a,b in dry dioxane and conc. sulphuric acid afforded pyridopyrimidinethione derivatives 27a,b. On the other hand, coupling of pyridopyridine 3 with the aromatic diazonium salt 28a-e afforded the corresponding azo products 29a-e. Boiling of compound 29 in aqueous solution of HCl afforded the hydrazo products 30. Treatmentof arylhydrazone 30a with malononitrile afforded the pyridazine derivatives 31.
期刊介绍:
Afinidad was founded in 1921 and is the oldest journal in theoretical and applied chemistry published nowadays in Spanish language. Afinidad accepts reviews, original articles and short communications about all aspects of chemical engineering, process engineering, chemistry and biotechnology.