Radioiodination and biodistribution of newly synthesized 3-benzyl-2-([3-methoxybenzyl]thio)benzo[]quinazolin-4-(3)-one in tumor bearing mice.

3-Benzyl-2-((3-methoxybenzyl)thio)benzo[]quinazolin-4(3)-one was previously synthesized and proved by physicochemical analyses (HRMS, H and C NMR). The target compound was examined for its radioactivity and the results showed that benzo[]quinazoline was successfully labeled with radioactive iodine using NBS via an electrophilic substitution reaction. The reaction parameters that affected the labeling yield such as concentration, pH and time were studied to optimize the labeling conditions. The radiochemical yield was 91.2 ± 1.22% and the studies showed that the target compound was stable for up to 24 h. The thyroid was among the other organs in which the uptake of I-benzoquinazoline has increased significantly over the time up to 4.1%. The tumor uptake was 6.95%. Radiochemical and metabolic stability of the benzoquinazoline and biodistribution studies provide some insights about the requirements for developing more potent radiopharmaceutical for targeting the tumor cells.