Syntheses of heterocyclic compounds. Part XXVI. Photo-rearrangements of benzimidazole N-oxides and related systems
Abstract
2,3-Dialkyl- and 2,3-polymethylene-benzimidazole 1-oxides are shown to rearrange when irradiated in neutral solution to give 1,3-dialkyl- and novel 1,3-polymethylene-benzimidazolones. The scope and mechanism of this rearrangement are discussed. Analogous 2,3-polymethylenequinoline 1-oxides and quinazolone 1-oxides react differently.