A mild, rapid synthesis of freebase [¹¹C]nicotine from [¹¹C]methyl triflate

A rapid, mild radiosynthesis of freebase [¹¹C]nicotine was developed by the methylation of freebase nornicotine with [¹¹C]methyl triflate in acetone (5min, 45°C). A basic (pH 10.5-11.0) HPLC system reproducibly yielded freebase [¹¹C]nicotine as a well-defined single peak. The freebase [¹¹C]nicotine was concentrated by solid phase extraction and formulated in 50µL ethanol (370MBq/50µL) without evaporative loss suitable for a cigarette spiking study. A radiochemical yield of 60.4±4.7% (n=3), radiochemical purity ≥99.9% and specific activity of 648GBq/µmol at EOB for 5min beams were achieved.