Abstract
124I-FIAU is a PET scan gene probe for the reporter gene-HSV1-tk-gene. When one wants to make 124I-FIAU as a PET scan probe for a therapeutic gene，some molecular biologic technology such as double-gene construct should be employed. By the technology, two genes (therapeutic gene and reporter gene-HSV1-tk-gene) can be connected together via IRES and share the same promoter. When the constructed double-gene is placed in a vector such as virus and transfected into the targeted cell or tissue, therapeutic gene and HSV1-tk gene will express simultaneously, once initiated by the promoter. 124I-FIAU can react with thymidine kianse translated —HSV1-tk gene, and then retain in the targeted cell. Through tracing by 124I-FIAU and PET imaging, the motion of the reporter gene and consequently the active region of therapeutic gene can be observed.This purpose of the thesis is to synthesize FTAU (5-Tributylstannyl -1-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)uracil) which is the precursor of 124I-FIAU as a gene probe for HSV1-tk gene. Several steps of the synthetic procedure for FIAU are crucial and critical, the experiments have been repeated many times. The optimal conditions have been established by which the production yield can reach to a maximum. The synthetic scheme is shown in Fig. 1.For step1, one has to get rid of moisture by using dehydrated solvents and setting a molecular sieve. Since the product of step 2 is unstable, one has to conduct step 3 after step 2 as soon as possible. By keeping the reaction temperature at 150 oC at reflux in step 2, one can get the best production yield at step 3 : 40.05%.When the refluxing time is controlled at about 5 h., one can get a very high production yield at step 4 : 72.95%. For step 6, one has to get rid of moisture so pure 25% ammonia must be used in the deprofection reaction . The whole yield can reach 2.93% by the synthetic procedure in accordance with the established optimal conditions.