LABELING PHARMACEUTICALS WITH RADIOACTIVE ISOTOPES December 1, 1975 to November 30, 1976

摘要

The purpose of this research is to prepare iodo- and bromoaliphatic amino acid analogs labeled with γ-emitting isotopesn( 131I, 123I and 77Br) ror possible use as pancreas localizing agents.nStudies on the halogen exchange reaction (I- for C1-) for the synthesis of 0-iodo-a-aminobutyric acid (a valine analog) have suggested that the iodo compound was formed initially. However, the desired compound cannot be isolated because of its chemical instability. Distribution studies in rats with the crude halogen exchange reaction mixture confirmed this finding. Studies on the addition of hydrogen iodide to allylglycine under various conditions for the synthesis of γ-iodo-α-aminopentanoic acid (a leucine analog) suffered the same obstacle; the chemical instability of the desired iodo compound precludes isolation and characterization.