Synthetic procedure to pyrido[2, 1-f][1, 2, 4]triazinium salt and related compounds. Issue 2 (11th January 2019)

• Record Type: Journal Article
• Authors: Bátori, Sándor; Csányi, Dorottya; Takács, Daniella; Egyed, Orsolya; Riedl, Zsuzsanna; Hajós, György
• Is Part Of: Tetrahedron. Volume 75:Issue 2(2019)
• Page Start: 180
• Page End: 185
• Publication Date: 2019-01-11
• Subjects: Ring closure -- Zwitterion -- Heteroaromatic -- Fused triazinium salt -- Covalent hydrate; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2018.11.070
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: N -aminopyridyl ketone salts were reacted with formamide to yield heteroaromatic pyrido[2, 1- f ][1, 2, 4]triazinium salts. Upon storage of these products in the presence of water, formation of covalent hydrates have been observed. Reaction of the same starting compound with urethane yielded 3-chloropyrido[2, 1- f ][1, 2, 4]triazinium salt which readily reacted with secondary amines to afford 3-amino derivatives. An analogous ring closure reaction of 2-formylaminomethyl- and formaminobenzylpyridine allowed the synthesis of the partially reduced 3, 4-dihydropyrido[2, 1- f ][1, 2, 4]triazinium compounds. The cyclization procedure was also applied for the synthesis of the related pyrimido[2, 1- f ][1, 2, 4]triazinium salt. Graphical abstract: