Synthesis and labeling 5'-O-(4-4'-dimetoxytrityl) -2,3-anhidrothymidine for preparation of radiopharmaceutical [¹⁸F]FLT

It is has been known that the compound of 3'-deoxy-3,-(¹⁸F] Fluorothymidine or (¹⁸F] FLT is a thymidine derivative radiopharmaceutical used for cancer detection based on DNA metabolism. Synthesis and labeling of 5'-0-(4,4 '-dimetoxytrityl) -2,3' anhidrothymidine precursor for preparation of the radiopharmaceutical [¹⁸F]FL T was carried out. The precursor was synthesized in similar manner and procedure literature and it have been obtained a crystalline product with total yield of 32,4 %. The chemical purity of the product which determined by HPLC was found to be more than 95%. Characterization of the product was done by observing the results of the LC / MS and ¹H-NMR test, the resulted data were found to be very closed to those reported in the literature. Labeling of the precursor was done by nucleophilic fluorination reactions using ¹⁸Fluoride at 160 °C for 15 minutes with kryptofix 2.2.2 catalyst followed hydrolysis using HCI at 100 °C for 10 minutes and then neutralized with NaOH. Purification [¹⁸F]FLT was performed by single cartridge Alumina-N as a substitute HPLC methods. The results have been obtained a label compound [¹⁸F]FLT with high purity as a bulk for preparation of the radiopharmaceutical [¹⁸F]FLT. The label compound of [¹⁸F]FLT undergone a quality test which included a clarity, pH and a radiochemical purity. The results of quality control on four batches of [¹⁸F]FLT showed that these products were colorless clear solution with pH between 6.0-7.5, and radiochemical purity 97.93 ± 1,48% and showed that the label compounds have been obtained [¹⁸F]FLT-free particles form a clear solution with a pH between 6,0 - 7,5, radiochemical purity of 97.93 ± 1,48 %, radiochemical yields 8.18 ± 1.54% (decay uncorrected) and processing time 73 ± 4 minutes. (author)