Rodnick ME, Brooks AF, Hockley BG, Henderson BD, Scott PJH. A fully-automated one-pot synthesis of [18F]fluoromethylcholine with reduced dimethylaminoethanol contamination via [18F]fluoromethyl tosylate.
Appl Radiat Isot 2013;
78:26-32. [PMID:
23665261 DOI:
10.1016/j.apradiso.2013.04.017]
[Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 04/02/2013] [Accepted: 04/08/2013] [Indexed: 02/02/2023]
Abstract
INTRODUCTION
A novel one-pot method for preparing [(18)F]fluoromethylcholine ([(18)F]FCH) via in situ generation of [(18)F]fluoromethyl tosylate ([(18)F]FCH2OTs), and subsequent [(18)F]fluoromethylation of dimethylaminoethanol (DMAE), has been developed.
METHODS
[(18)F]FCH was prepared using a GE TRACERlab FXFN, although the method should be readily adaptable to any other fluorine-(18) synthesis module. Initially ditosylmethane was fluorinated to generate [(18)F]FCH2OTs. DMAE was then added and the reaction was heated at 120 °C for 10 min to generate [(18)F]FCH. After this time, reaction solvent was evaporated, and the crude reaction mixture was purified by solid-phase extraction using C(18)-Plus and CM-Light Sep-Pak cartridges to provide [(18)F]FCH formulated in USP saline. The formulated product was passed through a 0.22 µm filter into a sterile dose vial, and submitted for quality control testing. Total synthesis time was 1.25 h from end-of-bombardment.
RESULTS
Typical non-decay-corrected yields of [(18)F]FCH prepared using this method were 91 mCi (7% non-decay corrected based upon ~1.3 Ci [(18)F]fluoride), and doses passed all other quality control (QC) tests.
CONCLUSION
A one-pot liquid-phase synthesis of [(18)F]FCH has been developed. Doses contain extremely low levels of residual DMAE (31.6 µg/10 mL dose or ~3 ppm) and passed all other requisite QC testing, confirming their suitability for use in clinical imaging studies.
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