Photochemical isomerization of 2H-imidazoleN-oxides
摘要:
1,3-Diaza-6-oxabicyclo[3.1.0]hex-3-enes and their 3-oxides were obtained by the photolysis of 2H-imidazole 1-oxides and 2H-imidazole 1,3-dioxides. 1,3-Diaza-6-oxabicyclo[3.1.0]hex-3-ene 3-oxides are thermally unstable and are converted to the starting 2H-imidazole 1,3-dioxides; their further photolysis affords a mixture of stereoisomeric 1,3-diaza-4,7-dioxatricyclo[4.1.0.0(3,5)]heptanes.
Synthesis of nitroxyl radicals ? Derivatives of 5,5-dimethoxy-3-imidazoline-3-oxide-1-oxyl from 2H-imidazole 1,3-dioxides
摘要:
2H-Imidazole 1,3-dioxides containing an aldonitrone fragment in the heterocyclic ring are obtained by the oxidation of 5-unsubstituted 1-hydroxy-3-imidazoline 3-oxides. Their further oxidation by lead dioxide in methanol leads to the formation of stable nitroxyl radicals - 5,5-dimethoxy-3-imidazoline-3-oxide-1-oxyls.