We synthesized and evaluated N-(5-fluoro-2-phenoxyphenyl)-N-(2-[18F] fluoromethyl-5- methoxybenzyl) acetamide ([18F]-FMDAA1106) and N-(5-fluoro-2-phenoxyphenyl)-N-(2- [18F] fluoroethyl-5-methoxybenzyl) acetamide ([18F] FEDAA1106) as two potent radioligands for peripheral benzodiazepine receptors (PBR).[18F] FMDAA1106 and [18F] FEDAA1106 were respectively synthesized by fluoroalkylation of the desmethyl precursor ...