Synthesis and biodistribution of 123I N-(2-aminoethyl)-5-iodo-2-pyridinecarboxamide (Ro 43-0463), a monoamine oxidase B inhibitor.

N-(2-Aminoethyl)-5-iodo-2-pyridinecarboxamide (Ro 43-0463) was radiolabeled with 123I in 22% radiochemical yield by anionic isotopic exchange in acidic medium. Biodistribution studies of this radioligand in rats showed peak brain uptake of 0.50% of the injected dose at 30 min and slow washout over 60 min.