Radiolabeling of 11C-sertraline by fast and easy loop method with [11C]CH3OTf

Cis-(1S,4S)-4-(3,4-dichlorophenyl)-1,2,3,4-tertrahydro-N-methyl-1-naphthalenamine (sertraline) hydrochloride from among selective serotonin reuptake inhibitors (SSRIs) is a treatment of major depression. For the differential diagnosis by metabolizing serotonin in a patient with neurological disorders, the radiolabeled $^{11}C$-sertraline was developed for non-invasive positron emission tomography in living brain and use the evaluation of new drug for SSRIs. We release the results of a fast and easy radiolabeling method applied a one-step loop method with $[^{11}C]CH_3OTf$ for routine clinical applications of $^{11}C$-sertraline. 1 mg of a precursor for $^{11}C$-sertraline in 0.1 mL DMF and $5{\mu}L$ of 1N NaOH, were injected into the loop of semi-prep high-performance liquid chromatography (HPLC). $[^{11}C]CH_3OTf$ was passed through the loop at room temperature (RT). The $^{11}C$-sertraline was separated by the semi-preparative HPLC. $^{11}C$-sertraline was eluted at 28.0 min was collected and evaluated by analytical HPLC and mass spectrometer. The total radiolabeling efficiency of $^{11}C$-sertraline was $30.7{\pm}8.7%$. The specific activity was $64.8{\pm}51.4GBq/{\mu}mol$. The radiochemical and chemical purities were higher than 99%. The mass spectrum of the product showed m/z peaks at 307.1 (M+1), indicating the mass of sertraline. By the one-step loop method with $[^{11}C]CH_3OTf$, $^{11}C$-sertraline could be quickly and easily prepared for clinical application.