The first design and synthesis of [11C]MKC-1 ([11C]Ro 31-7453), a new potential PET cancer imaging agent.

Bisindolylmaleimide MKC-1 (formerly known as Ro 31-7453) is a novel, orally active, small-molecule, cell cycle inhibitor with broad-spectrum antitumor effects. [(11)C]MKC-1 ([(11)C]Ro 31-7453) was first designed and synthesized as a new potential positron emission tomography cancer imaging agent through two different strategies. The first strategy was to prepare a carbon-11-labeled bisindolyl maleic anhydride intermediate followed by the conversion to maleimide. The second strategy involved the condensation of either carbon-11-labeled indole-3-acetamides with indole-3-glyoxalates, or indole-3-acetamides with carbon-11-labeled indole-3-glyoxalates. The radiochemical yields were 15-30%, decay corrected to end of bombardment (EOB), based on [(11)C]CO(2). The specific activity was 222-296 GBq/μmol at EOB and 111-148 GBq/μmol at the end of synthesis, respectively.