Behavior of 1-hydroxy-2,2,5,5-tetramethyl-3-imidazoline-3-oxide and the corresponding nitroxyl radicals in superacid media

Abstract

The protonation of 1-R-2,2,5,5-tetramethyl-3-imidazoline-3-oxides (R=OH, O) in superacid media was investigated with1H and13C NMR. The hydroxylamino dication forming on protonation can undergo imidazoline ring opening to form an isomeric mixture of diprotonated N-(2-hydroxyimino-1,1-dimethylethyl),α,α-dimethylnitrones.