A Facile Synthesis of Pyrido[2′, 3′:3, 4]pyrazolo[1, 5-a]pyrimidine and Pyrido[2′, 3′:3, 4]pyrazolo[5, 1-c][1, 2, 4]triazine Bearing a Thiophene Moiety. (14th November 2013)

• Record Type: Journal Article
• Authors: Elsaman, Tilal; Fares, Mohamed; Abdel-Aziz, Hatem A.; Attia, Mohamed I.; Ghabbour, Hazem A.; Dawood, Kamal M.
• Other Names: Gabriele Bartolo Academic Editor.
• Is Part Of: Journal of chemistry. Volume 2013(2013)
• Publication Date: 2013-11-14
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1155/2013/463515
• Languages: English
• ISSNs: 2090-9063

Abstract

Abstract : Pyridinone derivative 8 was synthesized and transformed into the respective chloropyridine 9, which was allowed to react with hydrazine hydrate to afford pyrazolo[3, 4- b ]pyridin-3-amine derivative 11 . Compound 11 was used as a key intermediate for a facile synthesis of the title compounds 14, 15, 17, 21a, b, and 24a–c where the reaction of 11 with some 1, 3-dielecrophiles resulted in the formation of pyrido[2′, 3′:3, 4]pyrazolo[1, 5- a ]pyrimidines 14, 15, and 17, whereas diazotization of compound 11 gave the respective diazonium salt 18 which was coupled with some active methylene-containing compounds to give the corresponding hydrazones 19a, b and 22a–c . Cyclization of the latter hydrazones yielded the pyrido[2′, 3′:3, 4]pyrazolo[5, 1- c ][1, 2, 4]triazines 21a, b and 24a–c, respectively.