Hetero-Cope rearrangement for the synthesis of potassium 5-tert-butyl-2-(tert-butyl-aminoxy)-benzoate, a highly water-soluble stable free radical

The hetero-Cope rearrangement of 4-tert-butyl-phenyl-tert-butylhydroxylamine provides an easy access to the corresponding ortho-bromoaniline, converted to the new highly water-soluble nitroxide, potassium 5-tert-butyl-2-(tert-butyl-aminoxy)-benzoate. The parent carboxylic acid was found to be very persistent in water at pH 1.