On triazoles XLV [1]. synthesis of 5,7‐diamino‐1,2,4‐triazolo[1,5‐a] [1,3,5]triazines

Abstract

The reaction of differently substituted 5-amino-1,2,4-triazoles (5) with isothiourea derivatives (3) to yield isomeric 5,7-diamino-1,2,4-triazolo[1,5-a][1,3,5]triazines (6 and 7), previously described as not proceeding in melt, was performed in different solvents as well as in the melt at 150-160°. It was proved that the above reaction had rather general validity. The structure of isomers 6 and 7 were proved spectroscopically. The structure of 6/5 (Q = ethylamino) was corroborated with single crystal X-ray diffraction determination, as well.

Synthesis of 5,7-Diamino[1,2,4]triazolo[1,2-a][1,3,5]triazines via Annulation of 1,3,5-Triazine Ring onto 3(5)-Amino-1,2,4-triazoles

“…For the comparison purpose 1,2,4-triazole (9) was prepared analogously from 6. The assignments were made based on the literature data [14][15] for related compounds as well as comparisons with 2-amino and methylthio substituted 5,7-diamino [1,2,4]triazolo [1,5-a] [1,3,5]triazines (2a,h) and unsubstituted at position 2 of the heterocyclic core (2i). 5 In order to provide conclusive results on the structure of the reaction products, for the comparison purpose, we decided to prepare 2,5,7-triamino[1,2,4]triazolo[1,5-a][1,3,5]triazine (2a) which structure had been previously established using X-ray crystallography.…”

Synthesis of azoles and azines and their condensed derivatives based on N-cyano-S-alkylthioureas (Review)

“…In reaction with 5-aminotriazole 43 N-cyanoisothiourea 3 reacts initially at the nitrogen atom at position 1 of the heterocycle. Subsequent cyclization in the intermediate with the participation of the amino group and the cyano group leads to the formation of 5,7-diamino-1,2,4-triazolo[1,5-a][1, 3,5]triazines 44 with yields of 4% [10]. With N-cyanoisothiourea 2 (R = Me, R 1 = Et) this reaction takes place in two directions with the formation of regioisomeric 5,7-diamino-1,2,4-triazolo[1,5-a][1, 3,5]triazines 45 and 46 [10].…”

“…By using various mono-or dialkylamines in this reaction it is possible to obtain good yields of the corresponding isothioureas 2 and 3 [8][9][10]. The reaction with aliphatic amines takes place at room temperature, while the reaction with aromatic amines takes place on heating in alcohol.…”