Radioiodination of amitriptyline by isotope exchange

The catalysed isotope exchange method was studied with the aim to elaborate the optimal procedure for labeling of amitriptyline with iodine¹²⁵I. Besides the catalysts published, cuprous salts and ammonium sulphate, a series of transition metal complexes as catalysts were tested at different reaction conditions. The best result (91% radiochemical yield) was achieved with trans-chlorocarbonylbis-(triphenylphosphine) iridium complex (Vaska catalyst) and sonification.