Rapid radiosynthesis of two [ 18 F]‐labeled nicotinamide derivatives for malignant melanoma imaging

Abstract The rapid synthesis of two radiofluoronicotinamide derivatives, namely, [ 18 F]MEL050 and [ 18 F]MEL-2F has been simply performed starting from commercial materials. [ 18 F]MEL-2F is a new, potential analogue PET-probe for melanoma imaging. [ 18 F]MEL050 is already an excellent PET imaging probe for early specific diagnosis. The synthesis involves coupling step to obtain the precursor followed by radiofluorination. During the synthesis of the precursors different coupling reagents, such as HBTU, TFFH, HOBT, COMU and PyCIU have been applied. PyClU was found the best to reduce the coupling period to