Synthesis of tritium labeled (±) 15‐deoxyspergualin trihydrochloride

Tritium labeled (±) 15‐deoxyspergualin, (±)‐7‐[(aminoiminomethyl) amino]‐N‐[2‐[[4‐[(3‐aminopropyl) amino]butyl]amino]‐1‐hydroxy‐2‐oxoethyl][4,5‐3H2]heptanamide trihydrochloride was prepared from the acid catalyzed condensation of 7‐guanidino[4,5‐3H2] heptanamide hydrochloride and glyoxyloylspermidine dihydrochloride in a total yield of 14.5%. The radiochemical purity was determined to be 91.1% and 95.4% on two different HPLC systems.