W. Banks, D. Hwang
May 1, 1994
Citations
0
Influential Citations
10
Citations
Journal
Applied Radiation and Isotopes
Abstract
Abstract A systematic study of parameters critical to the reproducible and high yield production of [ 18 F]fluoroarylketones via the aromatic nucleophilic substitution reaction (S n Ar) by NCA [ 18 F]F − using enolizable substrates was undertaken. This rational approach involved investigation of the following parameters: substrate, substrate concentration, base, base concentration, and microwave irradiation time. Using this approach, optimal conditions for the production of 4-[ 18 F]fluoroacetophenone (4-[ 18 F]FAP) were found, as reproducible yields approaching 80% (corrected) were realized; however these or other conditions were not applicable for the production of the positional isomer 2-[ 18 F]fluoroacetophenone. They were however found to be applicable with the preparation of 4-[ 18 F]fluoropropiophenone (4-[ 18 F]FPP). To explore the potential use of the bifunctional nature of [ 18 F]FAP, the productions of 1-bromo-4′-[ 18 F]fluoroacetophenone ([ 18F FAPBr), 1-(4′-[ 18 F]fluorophenyl) ethanol, and methyl 4-[ 18 F]fluorophenyl acetate were investigated. Optimization of the bromination of [ 18 F]FAP using a variety of reaction conditions was also investigated. Using the optimized reaction conditions, the desired monobrominated product was reproducibly obtained in radiochemical yields in excess of 80% (corrected). The latter two derivatives, 1-(4′-[ 18 F]fluorophenyl) ethanol and methyl 4-[ 18 F]fluorophenyl acetate were obtained in high yield and in rapid reaction times with no required optimization.