Urea-Inorganic Phosphate Mixtures as Prebiotic Phosphorylating Agents

Previous attempts to phosphorylate nucleosides by heating with inorganic phosphate succeeeded only when acid phosphates such as Ca(HPO$_{4}$)$_{2}$ were used. The addition of urea and ammonium chloride to the reaction mixture permits phosphorylation in high yield with neutral or basic phosphates at temperatures in the range of 65° to 100 °C. Since the abundant mineral, hydroxylapatite, is a satisfactory substrate for this reaction, we believe that this procedure provides a plausible model for prebiotic phosphorylation.