[18F]-2-(2-Nitroimidazol-1-yl)-N-(3, 3, 3-trifluoropropyl)-acetamide ([18F]-EF3) has been prepared, in 65% chemical yield and 5% radiochemical yield, by coupling 2, 3, 5, 6- tetrafluorophenyl 2-(2-nitroimidazol-1-yl) acetate 1 with [18F]-3, 3, 3-trifluoropropylamine 7. This original radiolabelled key-synthon was obtained in 40% overall chemical yield by oxidative [18F]-fluorodesulfurization of ethyl N-phthalimido-3-aminopropane dithioate 4, ...