15294-81-2

288-36-8

15294-81-2

Example 120: Preparation of 4,5-dibromo-1H-1,2,3-triazole. Bromine (1.5 mL, 29 mmol) was slowly added to a solution of 1H-[1,2,3]triazole (1.26 mL, 21.7 mmol) in water (10 mL) at 5 °C. The reaction mixture was stirred at 5°C for 1.5 h. The white solid (2.375 g) was isolated by filtration and washed with cold water (5 mL). Bromine (1.5 mL, 29 mmol) was added again to the combined filtrates. The mixture was stirred at room temperature for 20 h. More white solid (1.83 g) was separated by filtration and washed with cold water (5 mL). Bromine (1.5 mL, 29 mmol) was added a third time to the combined filtrates. The reaction mixture was stirred at room temperature for 20 h. Additional white solid (375 mg) was isolated by filtration and washed with cold water (5 mL). All white solids were combined and dried to give 4,5-dibromo-1H-[1,2,3]- triazole (4.92 g, 93% yield). Melting point: 194.7°C.