Preparation of N′4‐[11C]methyl‐ciprofloxacin for positron emission tomography studies

The synthesis of N′₄‐[¹¹C]methyl‐ciprofloxacin for pharmacological studies using positron emission tomography is described. The starting material was treated with [¹¹C]methyl iodide at 120°C in DMF for 5 min. After HPLC separation on a C₁₈‐column with water/ethanol as mobile phase, the [¹¹C]methyl labelled compound was produced with a radiochemical yield of at least 25% (end of synthesis from [¹¹C]CO₂). Activities from 1.48 to 2.22 GBq (40 to 60 mCi) were obtained 1 h after the irradiation, ready for intravenous injection. The carrier ranged between 0.05 and 0.08 μmol (0.010–0.016 μmol/ml). Copyright © 2002 John Wiley & Sons, Ltd.