A new phosphorylating agent, morpholinophosphorodichloridate was synthesized from phosphorylchloride and morpholine. The reagent was used successfully for the synthesis of adenosine 5'-monophosphate and 6-dimethylamino-9-β-D-ribofuranosylpurine 5'-monophosphate. Starting from 2', 3'-di-O-acetyladenosine, adenosine 5'-di- and triphosphate were synthesized by phosphorylation with this reagent followed by the reaction with inorganic phosphate or pyrophosphate in fairy good overall yield.