Lee Jihye, Cheong Il-Koo, Lee Sang-Yoon
Neuroscience Research Institute, Gachon University, 24, Namdong-daero 774 beon-gil, Namdong-gu, Incheon, Korea.
Gachon Advanced Institute for Health Science and Technology, Graduate School, Gachon University, 155, Gaetbeol-ro, Yeonsu-gu, Incheon, Korea.
Appl Radiat Isot. 2016 Dec;118:382-388. doi: 10.1016/j.apradiso.2016.10.006. Epub 2016 Oct 11.
[C]Raclopride is one of the most popular PET tracers used in Parkinson's disease studies. We previously prepared [C]raclopride with reasonable yields using NaOH as an inorganic base, but the reaction patterns fluctuated. In this study, we describe the successful application of a commercially available 'super basic' proton sponge, TMGN, as a base for the [C]methylation step using [C]CHOTf. This novel TMGN method produced better radiochemical yields, as well as enhanced reproducibility and a reduction in side products. Under optimal conditions (1.2 equiv. of TMGN), the radiochemical yield was 14.4±0.2% (ndc, EOS, n=5) and the specific activity was 66.6±13.3 GBq/mmol (n=5).
