A new synthetic way is described to prepare 4-trimethylammonio-2, 2, 6, 6- tetramethylpiperidine-1-yloxyl bearing tetrafluoroborate, hexafluorophosphate or bis ( trifluoromethylsulfonylimide) by an anion metathesis of 4-trimethylammonio-2, 2, 6, 6- tetramethylpiperidine-1-yloxyl iodide using the corresponding silver salts. 4- Trimethylammonio-2, 2, 6, 6-tetramethylpiperidine-1-yloxyl iodide is obtained by the ...