Synthesis of [3H]- and -[14C]-labeled sulprostone

The synthesis of N-methanesulfonyl 16-phenoxy-omega-tetranor PGE2 carboxamide (sulprostone--CP-34,089/ZK-57,671) labeled with tritium and carbon-14 is described. Sulprostone labeled with tritium in the phenoxy moiety by means of catalytic hydrogenolysis was obtained in a 17% radiochemical yield with a specific activity of 1.0 Ci/mmol. The methanesulfonamide-14C derivative of sulprostone was prepared from methyl-14C iodide in an 11.8% radiochemical yield having a specific activity of 18.8 mCi/mmol.