R. Gail, H. Coenen
1994
Citations
0
Influential Citations
13
Citations
Journal
Applied Radiation and Isotopes
Abstract
4-[18F]Fluorobromo- and [18F]fluoroiodobenzene are interesting precursors for organometallic nucleophilic reagents. A one-step preparation of these synthons was achieved by n.c.a. nucleophilic exchange on the corresponding 4-bromo- and 4-iodophenyl-trimethylammonium salts. The leaving ability of the trimethylammonium group increases strongly with decreasing basicity of the counter anion with the sequence: tosylate < methyl sulphate < iodide < (perchlorate) < triflate. Systematic optimization leads to radiochemical yields of 50 ± 5% and 80 ± 5% using dimethyl acetamide as a solvent within 5 min.