Selective reduction of 1,4-diarylimidazoline-3-oxides to imidazolidin-1-ols and hydroxylamine derivatives

Abstract

C-2-unsubstituted imidazoline-3-oxides were reduced with NaBH4 in THF to give the corresponding trans-3,5-diarylimidazolidin-1-ols, while under the same conditions C-2-substituted derivatives gave the corresponding ring-chain-ring tautomers. Treatment of the crude reaction mixture from the reduction of C-2-unsubstituted imidazoline-3-oxides with a MeOH-H2O mixture provided reductive C-N bond cleavage to give hydroxylamines, while under the same conditions ring-chain-ring tautomers remained unchanged.