Synthesis and structure elucidation of novel 5-dinitromethyl-7-alkylamino-1,2,4-triazolo[4,3-a]-1,3,5-triazines

Synthesis of new 5-aza-isosteres of guanine—5-aminosubstituted 1,2,4-triazolo[1,5-a]-1,3,5-triazin-7-ones

“…15 Moreover, the triazole ring proton resonance in the 1 H NMR spectra of 1,2,4-triazolo[4,3-a]-1,3,5-triazinones appears at a lower field (8.80e8.82 ppm). 16 Although these data are suggestive of the structure of isomers, only the analysis of the 13 C spectra and 2D HMBC experiments followed by an X-ray analysis of selected compounds 3a and 3g allowed unambiguous structural assignments to be made. The 1,2,4-triazole carbon resonance at the range of 150e156 ppm in the 13 C NMR spectra of 3aeg confirms the formation of the [1,5-a]-isomers on the basis of existing structural data.…”

Bicyclic 5-6 Systems With One Bridgehead (Ring Junction) Nitrogen Atom: Four Extra Heteroatoms 2:2

“…X-ray crystal structure analyses have proven the structure of the products (Scheme 59). 114 All the reported procedures for the access to this fused ring systems rely on the use of 2-amino-1,3,4-oxa-or thia-diazole derivatives which undergo a cyclocondensation or an intramolecular cyclization to build the triazine ring.…”