Simple and effective method for producing [11C]phosgene using an environmental CCl4 gas detection tube

IntroductionCarbon-11-labeled phosgene is an important labeling precursor for PET molecular probes. Despite the usefulness of [11C]phosgene, some difficulties, especially in the formation of [11C]phosgene process from [11C]CCl4, hamper its use. The present article shows a simple preparation method for [11C]phosgene.Method[11C]CCl4 was obtained using the conventional method by passing a mixture of [11C]CH4 and Cl2 through a heated quartz tube. The [11C]CCl4 was transformed to [11C]phosgene simply by passing through a pretreatment tube of a Kitagawa gas detection system for the working-environmental CCl4 concentration measurement at room temperature with a flow rate of 50 ml/min.ResultThis tube successfully transformed [11C]CCl4 to [11C]phosgene at room temperature. [11C]Phosgene was obtained at nearly 80% radiochemical yield (EOB) in a short synthesis time with high reproducibility.ConclusionA high yield and reliable [11C]phosgene production method using a gas detector tube system for working-environmental CCl4 concentration measurement was developed.