title: Investigation of the role of the base in the synthesis of [18F]FLT.
abstract: The role of the base in the synthesis of 3'-deoxy-3'-[18F]fluorothymidine, [18F]FLT, via nucleophilic substitution of the nosyl group with [18F]fluoride was investigated. The rate of 18F-incorporation into the molecule dramatically changed as a function of the precursor-to-base ratio. In the presence of excess base, the precursor was consumed by elimination before substitution was complete. When the precursor-to-base ratio was optimal, an overall [18F]FLT yield of 30-40% was achieved even if the precursor amount was as small as 8-13 mg.
authors.affiliation: Citigroup Biomedical Imaging Center, Weill Medical College of Cornell University, 516 East 72nd Street, New York, NY 10021, USA. suehirom@MSKCC.ORG
authors.forename: Makiko
authors.initials: M
authors.lastname: Suehiro
authors.forename: Shankar
authors.initials: S
authors.lastname: Vallabhajosula
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Goldsmith
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Ballon
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D015224:Dideoxynucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D006801:Humans; D015394:Molecular Structure; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D015224:Dideoxynucleosides; D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; C002854:alovudine