Synthesis of carbon-11-labeled casimiroin analogues as new potential PET agents for imaging of quinone reductase 2 and aromatase expression in breast cancer

Carbon-11-labeled casimiroin analogues were first designed and synthesized as new potential PET agents for imaging of quinone reductase (QR) 2 and aromatase expression in breast cancer. [C-11]casimiroin (6-[C-11]rnethoxy-9-methyl-[1,3]dioxolo[4,5-h]quinolin-8(9H)-one, [C-11]11) and its carbon-11-labeled analogues 5,6,8-trimethoxy-1-[C-11]methyl-4-methylquinolin-2(1H)-one ([C-11]17), 8-methoxy-1-[C-11]methyl-4-methylquinolin-2(1H)-one ((11)[C]21a), 6,8-dimethoxy-1-(11)[C]methyl-4-methylquinolin-2(1H)-one ([C-11]21b), and 5,8-dimethoxy-1-[C-11]methyl-4-methylquinolin-2(1H)-one ([C-11]21c), were prepared from their corresponding precursors with [C-11]methyl triflate ([C-11]CH3OTf) under basic conditions (NaH) through either O- or N-[C-11]methylation and isolated by semi-preparative HPLC method in 40-50% radiochemical yields decay corrected to end of bombardment (EOB), based on [C-11]CO2, and 111-185 GBq/mu mol specific activity at the end of synthesis (EOS). (C) 2010 Elsevier Inc. All rights reserved.