Synthesis of [14C]A‐62514, a radiolabelled derivative of erythromycin a, via [2‐14C]N, N‐dimethylethylenediamine

The synthesis of [14C]A-62514, 11-deoxy-11-[carboxy(2-dimethylamino-[1-14C]ethyl)amino]-6-0-methyl-erythromycin A 11,12-(cyclic ester), was performed in five steps. The key intermediate, [2-14C]N, N-dimethylethyl-enediamine, was obtained in 80% yield by reacting Eschenmoser's salt with K14CN and reducing the resulting [1-14C]N, N-dimethylglycinonitrile with H12 and Raney Ni in methanol and ammonium hydroxide. The final product was obtained 97% radiochemically pure in an overall radiochemical yield of 14%, with a specific activity of 39 mCi/mmol.