Synthesis of Di-and Polynitroxides by Favorskii Rearrangement of Polyamines on Cis-3,5-dibromo-4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl

Abstract

The reaction of cis 3,5-dibromo-4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl (1) with polyamines provides a convenient and a short way to synthesize polynitroxides spin labels in a good yield where 3-carboxy-2,2,5,5-tetramethylpyrrolin-1-oxyl (3) is a nitroxyl moiety obtained by contraction of a ring from six (1) to five (3) in a Favorskii rearrangement under nucleophilic action of primary or secondary amines.