The reaction of 2'-deoxy-5-fluoro-3'-O-oleoyluridine (I) with 2-bromoethylphosphodichloridate (II) by means of lutidine in THF gives 2'-deoxy-5-fluoro-3'-O-oleoyluridine 5'-(2-bromoethyl)phosphate (III), which is then condensed with trimethylamine (IV) in toluene.