Labeling of EGFR inhibitor to prepare a potential SPECT agent for molecular imaging of breast cancer via iodine-bromine exchange

A simple method was developed for labeling N-{4-(3-chloro-4-fluorophenyl)amino]quinazolin-6-yl}-3-bromopropionamide, an EGFR inhibitor, with radioactive iodine via nucleophilic iododebromination. The factors affecting the radiochemical yield of ¹²⁵I-EGFR such as reaction medium, substrate concentration, CuCl concentration, and temperature were examined. Reducing agents such as ascorbic acid, SnCl₂, and Na₂S₂O₅ were used to prevent disproportionation. The radiochemical yield and purity of the labeled product were determined by TLC and HPLC.