Phosphorylation of 5'-deoxy-5-fluorouridine with inorganic phosphorylating agents.

The phosphorylation of 5'-deoxy-5-fluorouridine (doxifluridine, 5'-DFUR) has been achieved using inorganic cyclo-triphosphate (P(3m), Na(3)P(3)O(9)) and monoimido-cyclo-triphosphate (MCTP, Na(3)P(3)O(8)NH) in aqueous solution. In the reaction of 5'-DFUR with P(3m), 2'-monophospho-5'-DFUR and 3'-monophospho-5'-DFUR were synthesized with a total yield of more than 95%. In the reaction of 5'-DFUR with MCTP, 2'-diphosphoramidophosphono-5'-DFUR and 3'-diphosphoramidophosphono-5'-DFUR were synthesized with a total yield of more than 40%. The phosphorylated products with P(3m) and MCTP were stable in neutral and alkaline solutions.