Premium
Synthesis of tritium‐labelled phosphonium choline
Author(s) -
Sim Edith
Publication year - 1984
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.2580210612
Subject(s) - chemistry , phosphonium , tritium , chloride , methylene , radiochemistry , deuterium , hydrogen , proton , inorganic chemistry , medicinal chemistry , nuclear chemistry , organic chemistry , physics , quantum mechanics , nuclear physics
Tritium‐labeled phosphonium choline chloride ([2‐hydroxyethyl] trimethyl phosphonium chloride) has been synthesized using base‐catalyzed hydrogen exchange of the hydrogen atoms attached to the carbon adjacent to the phosphonium phosphorus. Using 3 H 2 O diluted in 2 H 2 O, during the exchange reaction, it is shown by proton‐NMR that substitution of the methylene protons is almost complete when only 25% of the methyl protons have exchanged. Comparison of the measured specific activity (16.12mCi/mmol) with that calculated from the total proton exchange values shows that there is a large isotope effect favouring exchange to deuterium rather than tritium.