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

Dedicated to Professor András Messmer on the occasion of his 80^th birthday

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.