title: Synthesis of 18F-6-fluoropurine and 18F-6-fluoro-9-beta-d-ribofuranosylpurine.
abstract: Introduction of fluorine-18 into the 6-position of purines is described. 18F-6-fluoropurine and 18F-6-fluoro-9-beta-D-ribofuranosylpurine were prepared with high radiochemical yields by nucleophilic displacement of the trimethylammonio-group of purine with 18F-fluoride under mild conditions. 18F-labeling conditions such as reaction temperature and time, addition of crown ether and dose of a substrate have been studied. Under adequate conditions, yields of about 38% in the case of free base and about 63% in the case of ribofuranosyl derivative have been obtained. The latter compound has also been prepared in a non-carrier-added state. The stability of 18F-purines was examined in Tris buffer at 37 degrees.
mesh_terms: D005472:Fluorouracil / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D007553:Isotope Labeling; D009369:Neoplasms / Q000000981:diagnostic imaging; D011687:Purines / Q000138:chemical synthesis*; D011877:Radionuclide Imaging; D011956:Receptors, Cell Surface / Q000032:analysis; D011983:Receptors, Purinergic
chemical_list: D011687:Purines; D011956:Receptors, Cell Surface; D011983:Receptors, Purinergic; C035106:6-fluoropurine; C035107:6-fluorouracil; D005472:Fluorouracil