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A new and efficient synthesis of monotritiomethyl iodide
Author(s) -
Saljoughian Manouchehr,
Morimoto Hiromi,
Dorsky Albert M.,
Rapoport Henry,
Andres Hendrik
Publication year - 1989
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.2580270705
Subject(s) - chemistry , tritium , iodide , dimethylformamide , methyl iodide , reagent , chloride , tritium illumination , radiosynthesis , yield (engineering) , zinc bromide , paraformaldehyde , bromide , nuclear magnetic resonance spectroscopy , zinc , radiochemistry , organic chemistry , nuclear chemistry , physics , materials science , microbiology and biotechnology , solvent , in vivo , nuclear physics , metallurgy , biology
A new and efficient synthesis of high specific activity TCH 2 I containing one atom of tritium per molecule is reported. The precursors for this reagent, chloromethyl p‐phenylbenzoate or bis‐chloromethyl terephthalate, were prepared by the condensation of the corresponding acid chlorides with paraformaldehyde in the presence of zinc chloride. Tritiodehalogenation of the precursors with tritium gas and Pd‐C (10%) in dimethylformamide afforded the desired tritioesters. Cleavage of the esters by lithium iodide at 180°C (SN 2 type reaction), or by HI at 140°C gave mono tritium labeled methyl iodide in more than 95% yield. The reaction of the latter with a number of amines yielded tritium labeled N‐methylated products readily as was shown by Radio‐HPLC. The specificity of the labeling in the final products was confirmed by tritium nmr spectroscopy.