Synthesis and Crystal Structures of Dibromo-Triazoles and their Amination

Triazole heterocyclic compounds have a wide range of applications in the fields of medicine, pesticide, energetic materials, etc. Introducing halogen atoms and amino groups into the triazole ring can obtain a series of important intermediates that can be further modified. 4,5-Dibromo-1-H-1,2,3-triazole (5), 3,5-dibromo-1-H-1,2,4-triazole (6), 3,5-dibromo-4-H-1,2,4-triazole (7) and 1-amino-4,5-dibromo-1,2,3-triazole (8), 2-amino-4,5-dibromo-1,2,3-triazole (9) and 1-amino-3,5-dibromo-1,2,4-triazole (10) were synthesized through the bromination and amination of 1,2,3-triazole (1), 1-amino-1,2,3-triazole (2), 1,2,4-triazole (3) and 4-amino-1,2,4-triazole (4). Their structures were characterized by IR, EI-MS, ESI-MS, 1H and13C-NMR techniques. Single crystals of these compounds were grown by evaporation solution growth technique. The cell parameters and crystal structures were determined by X-ray single crystal diffraction studies. Among these compounds, 6 and 7, 8 and 9 were isomers, respectively. Through intermolecular hydrogen bonding, 1 forms zigzag chain structure, while 4 and 5 form cyclic trimers.