Prostate cancer PET bioprobes: synthesis of [18F]-radiolabeled hydroxyflutamide derivatives.

Approximately 80-90% of prostate cancers are androgen dependent at initial diagnosis. The androgen receptor (AR) is present in most advanced prostate cancer specimens and is believed to have a critical role in its development. Today, treatment of prostate cancer is done by inhibition of AR using antiandrogens such as flutamide (pro-drug of hydroxyflutamide), nilutamide, and bicalutamide. However, there is currently no noninvasive imaging modalities to detect, guide, and monitor specific treatment of AR-positive prostate cancer. (R)-3-Bromo-N-(4-fluoro-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methyl-propanamide [18F]-1 and N-(4-fluoro-3-(trifluoromethyl)phenyl)-2-hydroxy-2-methylpropanamide [18F]-2, derivatives of hydroxyflutamide, were synthesized as a fluorine-containing imaging agent candidates. A three-step fluorine-18 radiosynthesis route was developed, and the compounds were successfully labeled with a 10+/-3% decay corrected radiochemical yield, 95% radiochemical purity, and a specific activity of 1500+/-200 Ci/mmol end of bombardment (n = 10). These labeled biprobes not only may enable for the future quantitative molecular imaging of AR-positive prostate cancer using positron emission tomography but may also allow for image-guided treatment of prostate cancer.

A fast, high-yield preparation of vicinal dinitro compounds using HOF.CH3CN.

HOF.CH3CN, a very efficient oxygen-transfer agent, was reacted with various aliphatic and aromatic vicinal diamino compounds. The products were the rare, vicinal dinitro derivatives formed in excellent yields and short reaction times. This is in contrast to other oxygen-transfer agents which tend to break the central C-C bond of the diamino precursor. This reaction was also used for making dinitro compounds with all four oxygens, being the [18]O isotope.