28610-05-1Relevant academic research and scientific papers
Fused heterocyclic systems with an s-triazine ring. 34. Development of a Practical Approach for the Synthesis of 5-Aza-isoguanines
Junaid, Ahmad,Lim, Felicia Phei Lin,Zhou, Yvonne Peijun,Chui, Wai Keung,Dolzhenko, Anton V.
, (2019/05/02)
Purine isosteres present excellent opportunities in drug design and development. Using isosteres of natural purines as scaffolds for the construction of new therapeutic agents has been a valid strategy of medicinal chemistry. Inspired by the similarity to isoguanine, we attempted to develop a practical method for the preparation of 5-aza-isoguanines. Several synthetic approaches were explored to establish a robust general protocol for the preparation of these compounds. The significant difference in the reactivity of the C-5 and C-7 electrophilic centers of 1,2,4-triazolo[1,5-a][1,3,5]triazines (5-azapurines) towards nucleophiles was demonstrated. The most practical and general method for the preparation of 5-aza-isoguanines involved a regioselective reaction of ethoxycarbonyl isothiocyanate with a 5-aminotriazole. The intramolecular ring closure of the resulted product followed by the S-methylation afforded 7-methylthio-2-phenyl-1,2,4-triazolo[1,5-a][1,3,5]triazin-5-one, which could be effectively aminated with various amines. The resulted 5-aza-isoguanines resemble a known purine nucleoside phosphorylase inhibitor and could be interesting for further investigations as potential anticancer agents.
A convenient method for the synthesis of 7-amino-substituted 1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amines
Dolzhenko, Anton V.,Pastorin, Giorgia,Dolzhenko, Anna V.,Chui, Wai Keung
scheme or table, p. 7180 - 7183 (2009/04/10)
A new practical synthesis of 7-amino-substituted 1,2,4-triazolo[1,5-a][1,3,5]triazin-5-amines is developed. The triazine ring closure of 5-guanidino-3-phenyl-1,2,4-triazole with trichloroacetonitrile proceeds chemo- and regioselectively depending on the n
Synthesis of 5,7-diamino1,2,4 triazolo[1,2-a1,3,5 triazines via annulation of 1,3,5-triazine ring onto 3(5)-amino-1,2,4-triazoles
Dolzhenko, Anton V.,Dolzhenko, Anna V.,Chui, Wai-Keung
, p. 429 - 436 (2008/02/09)
The 5,7-diamino[1,2,4]triazoeo[1,5-a][1,3,5]triazines were synthesized by cyclocondensation of 3(5)-amino-1,2,4-triazoles with cyanoguanidine. The substituted 3(5)-amino-1,2,4-triazoles were prepared from corresponding hydrazides and S-methylisothiourea via ring closure of the intermediate acylaminoguanidines. The 3,5-diamino-1,2,4-triazoles were prepared using partial aminolysis of dimethyl N-cyanodithiocarbonimidate followed by cyclization of the obtained N-substituted N′-cyano-S-methylisothioureas with hydrazine. The structures of the prepared compound were confirmed using NMR spectral data.
