A versatile synthesis of 2‐amino‐4H‐pyrido[1,2‐a][1,3,5]triazin‐4‐ones from 2‐aminopyridines

Abstract

The quasi-one pot synthesis of new 2-aminopyrido[1,2-a][1,3,5]triazin-4-ones starting from 2-aminopyridine and 2-aminopicolines is herein described in order to obtain a library of cyclic guanidines.

A Facile Three-Steps, One-Pot Synthesis of Novel 2-Alkylamino and 2-Dialkylamino-4H-Pyrido[1,2-A][1,3,5] Triazin-4-Ones from 2-Aminopyridine and 2-Aminopicolines

“…iii) one-pot: DMF, 80°C, 2h Primas et al [12] have recently studied one pot syntheses of pyrimidocarbazole starting from 3-aminocarbazoles. In another paper, the same authors [13] described a three-steps methodology, one pot synthesis of novel 2-alkyl(aryl)amino and 2dialkylamino-7H-[1, 3,5]triazino [3,4-b] pyridoilndol-4-one andderivatives starting 3-amino-β-carbolines in similar conditions to our work [14]. Finally, this project aims at synthesizing series of pyrido[1, 2-a][1, 3,5]triazines analogues [14], via ring annulations, as potential TP inhibitors.…”

“…In another paper, the same authors [13] described a three-steps methodology, one pot synthesis of novel 2-alkyl(aryl)amino and 2dialkylamino-7H-[1, 3,5]triazino [3,4-b] pyridoilndol-4-one andderivatives starting 3-amino-β-carbolines in similar conditions to our work [14]. Finally, this project aims at synthesizing series of pyrido[1, 2-a][1, 3,5]triazines analogues [14], via ring annulations, as potential TP inhibitors. In the following, we will report a new simple and efficient one-pot synthesis of hitherto unknown title compounds.…”

“…On the other hand, we ourselves published [14] in 2002 a quasi-one-pot synthesis of 2-amino-4H-pyrido[1,2-a][1, 3,5]triazin-4-ones from 2-aminopyridine (Figure 4). The isolation of the intermediates was not necessary and this sequence became applicable to parallel chemistry techniques.…”

A rapid and versatile synthesis of novel pyrimido[5,4-b]carbazoles

“…26 This method involved the introduction of the dialkylamino group in the reaction intermediate, i.e., formation of a ethoxycarbonylguanidine, before carrying out the ring closure step. Thus, the formation of the ethoxycarbonylguanidines 7 was performed in one pot starting from the 3-aminocarbazole 1a by successive addition of the reagents: ethoxycarbonylisothiocyanate, diethylamine, and HgCl 2 to the reaction mixture with the indicated stoichiometry as shown in Scheme 2.…”

Oxidant‐Mediated Nitrogenation and Recyclization of Imidazo[1,2‐a]pyridines with Sodium Azide: Synthesis of 4H‐Pyrido[1,2‐a][1,3,5]triazin‐4‐ones

“…Among various derivatives of [1,3,5]triazin‐4‐ones, pyrido[1,2‐ a ]‐1,3,5‐triazin‐4‐ones have been rarely studied and only a few relevant reports were documented, whereas they were used as key structures in DNA oligomers . The traditional methods for the synthesis of diversely substituted pyrido[1,2‐ a ]‐1,3,5‐triazin‐4‐ones constituted the reaction of N ‐fluoropyridinium salts with cyanate ion and carbonitriles, the reaction of 2‐amino‐pyridine with ortho ‐ester and trimethylsilyl isocynante or with ethoxycarbonyl isothiocyanate and mercury(II) salt,, and the reaction of 2‐amino‐pyridine with N ‐Benzyloxycarbonyl‐2,2,2‐trifluoroacetimidoyl chloride . However, the above synthetic approaches suffered from multistep reaction procedures, low efficiency and poor regioselectivity, or the necessity of pre‐functionalized starting materials.…”