A convenient synthesis of 5-fluoropyrimidines using 1-(chloromethyl)-4-fluoro-1,4-diazabicyclo[2.2.2]octane bis(tetrafluoroborate)-SELECTFLUOR reagent

Article abstract of DOI:10.1021/jo00127a046

The pyrimidine bases uracil and thymine react with the titled reagent in water to generate the corresponding fluorohydrins. Uracil fluorohydrin provides 5-fluorouracil on sublimation. Triacetyluridine reacts similarly in the presence of H₂O, AcOH, or MeOH to form the respective adducts from which 5-fluorotriacetyluridine was obtained. The fluorohydrin of diacetylthymidine and the difluoromethoxy derivative of triacetylcytidine were also obtained by reaction of the nucleosides with 1-(chloromethyl)-4-fluoro-1,4-diazobicyclo[2.2.2]octane bis(tetrafluoroborate)-SELECTFLUOR in H₃O and MeOH, respectively. This method represents a new practical and direct route to 5-fluoropyrimidine nucleoside.