Abstract
Adenosine 5'-phosphate was converted to the 2', 3'-cyclic phosphate by the treatment with dimethylformamide at reflux temperature. The reaction was shown to be proceeded by the initial release of the phosphoryl group as an"activated phosphoric acid"and rephosphorylated to furnish the 2', 3'-cyclic phosphate. In fact a ribonucleoside and phosphoric acid, pyrophosphoric acid, or polyphosphoric acid gives a 2', 3'-cyclic phosphate in a satisfactory yield in refluxing dimethylformamide. This procedure will serve for the preparation of the 2', 3'-cyclic phosphate of synthetic ribonucleoside of a limited quantity.
