INSTANTANEOUS PREPARATION OF RADIOLABELED 5-IODO-2'-DEOXYURIDINE

The fastest and most reliable preparation of radiolabeled 5-iodo-2'-de oxyuridine ([I-123/125/131]IUdR) is accomplished by iododemetallation. We describe a series of improvements to a previously published synthe sis of radiolabeled IUdR by demercuration whereby [I-123/125/131]IUdR is synthesized instantly following the incubation of an aqueous soluti on of the chloromercury precursor with (NaI)-I-123/125/131 in the pres ence of Iodogen. The total procedure is completed in 5 min and does no t require purification. Mercury content is low and HPLC indicates the total transformation of iodide into IUdR with no detectable UV-absorbi ng by-products.