The new convenient synthesis of 6-fluoropurine and its 7-/9-unsubstituted analogues
6-Fluoropurine and its 7-/9-unsubstituted analogues have good biological activity and serve as important pharmaceutical intermediates. This paper describes a new and convenient synthesis of 6-fluoropurine and its 7-/9-unsubstituted analogues, by first replacing the chlorine atoms with trimethylammonio groups through the reaction of 6-chloropurine and its 7-/9-unsubstituted analogues with trimethylamine, and then replacing the trimethylammonio groups with fluorine atoms using safe and cheap TBAF·3H2O as fluorinating agent at room temperature. Compared with reported methods, the new synthesis has milder conditions, shorter reaction times, simpler post-processing and higher (or similar) yields.