Synthesis of 2-Amino-6-fluoro-9-(4-hydroxy-3-hydroxymethylbutyl)purine

The fluorinated nucleoside analogue 2-amino-6-fluoro-9-(4-hydroxy-3- hydroxymethylbutyl)purine (1) is a potential antiviral agent and ¹⁸F-radiopharmaceutical reference compound. Its synthesis was described. 2-Amino-6-chloro-9-(4-acetoxy-3-acetoxymethylbutyl)purine (2) was hydrolyzed to 2-amino-6-chloro-9-(4-hydroxy-3-hydroxymethylbutyl)purine (3) by using potassium carbonate in a mixed solution of water and methanol at 0 °C, then was converted to the corresponding trimethylammonium chloride (4) by treatment with trimethylamine (TMA) in ethanolic solution in a mild condition. Compound 4 was reacted with anhydrous KF in DMF to produce 2-amino-6-fluoro-9- (4-hydroxy-3-hydroxymethylbutyl)purine (1) in 87.3% yield. The structures of the products were characterized by UV-vis, IR, NMR and MS spectra. Some factors affecting the yield of fluorination reaction were investigated.