Two-step radiosynthesis of [18F]N-succinimidyl-4-fluorobenzoate ([18F]SFB)
Abstract
The acylation reagent [18F]N-succinimidyl-4-fluorobenzoate (18F-SFB) has been prepared using a new two-step approach. The starting material p-[18F]fluorobenzaldehyde (18F-FBA) was obtained by an improved radiosynthesis with a decay-corrected radiochemical yield of 66±6 % (n=3). Reaction of 18F-FBA with (diacetoxyiodine)benzene and N-hydroxysuccinimide and preparative HPLC purification furnished 18F-SFB in an r.c.y. of 49±6 % (n=3), based on the starting radioactivity of 18F-FBA. The radiochemical purity of 18F-SFB was >99%. Alternatively, purification by solid phase extraction gave 18F-SFB with an r.c.y. of 77±9% (n=4) and a radiochemical purity of 89±5% (n=4). This radiochemical synthesis only used non-aqueous solvents, which simplifies the method and facilitates subsequent applications of 18F-SFB. Copyright © 2009 John Wiley & Sons, Ltd.