New Synthesis of Nitroxyl Radicals of the Piperidine and Tetrahydropyridine Series

Abstract

1-Oxyl-2,2,6,6-tetramethyl-4-piperidone cyanohydrin (5) was prepared by addition of HCN to 1-oxyl-2,2,6,6-tetramethyl-4-piperidone (4). The cyanohydrin was used to synthesize 1-oxyl-4-carboxy-2,2,6,6-tetramethylpiperidine (2) and 1-oxyl-4-carboxy-2,2,6,6-tetramethyl-1,2,5,6-tetrahydropyridine (3) which are useful nitroxyl radicals for spin labeling studies.