Synthesis of new carbon-11 labeled naphthalene-sulfonamides for PET imaging of human CCR8

Carbon-11 labeled naphthalene-sulfonamides, N-(4-(N-(4-[11C]methoxyphenyl)sulfamoyl)naphthalene-1-yl)benzamide ([11C]5a), N-(4-(N-(4-[11C]methoxyphenyl)sulfamoyl)naphthalene-1-yl)-2-methylbenzamide ([11C]5b), N-(4-(N-(4-[11C]methoxyphenyl)sulfamoyl)naphthalene-1-yl)-3-methylbenzamide ([11C]5c), N-[11C]methyl-N-methyl-4-(4-benzamidonaphthalene-1-sulfonamido)piperidine-1-carboxamide ([11C]9a) and N-[11C]methyl-N-methyl-4-(4-(2-methylbenzamido)naphthalene-1-sulfonamido)piperidine-1-carboxamide ([11C]9b), have been synthesized as new potential positron emission tomography (PET) agents for imaging of human CCR8. The target tracers were prepared by either O-[11C]methylation or N-[11C]methylation of their corresponding precursors using [11C]CH3OTf and isolated by either a simplified solid-phase extraction (SPE) purification procedure or a high pressure liquid chromatography (HPLC) method in 30–50% radiochemical yields decay corrected to end of bombardment (EOB), 20–25 min overall synthesis time, and 74–111 GBq/μmol specific activity at end of synthesis (EOS).