21410-06-0

21324-31-2

21410-06-0

General procedure for the synthesis of 3-benzyl-7-chloro-3H-[1,2,3]-triazolo[4,5-d]pyrimidines from 3-benzyl-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7-ol: To chloroform (50 mL) containing 3-benzyl-7-hydroxy-3H-[1,2,3]triazolo[4,5-d]pyrimidines (10.56 mmol) suspension, N,N-dimethylformamide (DMF, 2 mL) and thionyl chloride (9 mL) were added sequentially. The reaction mixture was heated to reflux for 3 hours. After completion of the reaction, the solvent was removed by evaporation under reduced pressure at a temperature below 35 °C. The crude product was purified by silica gel column chromatography with mixed petroleum ether-ethyl acetate solvent as eluent. The final white solid product 3-benzyl-7-chloro-3H-[1,2,3]-triazolo[4,5-d]pyrimidine (1.14 g, 44% yield) was obtained.