2065-75-0

61-82-5

89167-24-8

General procedure for the synthesis of 6-bromo-[1,2,4]triazolo[1,5-a]pyrimidines from 2-bromomalonaldehyde and 1H-1,2,4-triazol-5-amine: 3-amino-1H-1,2,4-triazole (6 mmol, 0.5 g) was dissolved in 5 mL of anhydrous acetic acid and slowly added dropwise at room temperature to a 2-bromomalonaldehyde (6 mmol, 0.9 g) in 5 mL of anhydrous acetic acid in suspension. The reaction mixture was heated to 80 °C and maintained for 7 hours. Upon completion of the reaction, the acetic acid was removed by evaporation under reduced pressure. Dichloromethane (DCM) was added to the residue, and the organic phase was washed with saturated sodium bicarbonate solution and brine, dried over anhydrous sodium sulfate, and concentrated to dryness under reduced pressure to yield 918 mg (78% yield) of 6-bromo-[1,2,4]triazolo[1,5-a]pyrimidine, which was of sufficient purity to meet the requirements for subsequent use.