2H-Benzimidazole 1,3-dioxides undergo thermal isomerization to 3H-2,1,4-benzoxadiazine 4-oxides which are converted to 2H-benzimidazole 1-oxides on further heating. Irradiation of 3H-2,1,4-benzoxadiazine 4-oxides with sunlight induces their transformation to 2H-benzimidazole 1,3-dioxides. 3H-2,1,4-Benzoxadiazine 4-oxides containing nucleophilic heterocyclic substituents are considerably more stable to sunlight
使2 H-
苯并咪唑1,3-二氧化物热异构化为3 H -2,1,4-苯并恶二嗪4-氧化物,然后进一步加热将其转化为2 H-
苯并咪唑1-氧化物。用阳光照射3 H -2,1,4-苯并恶二嗪4-氧化物诱导其转化为2 H-
苯并咪唑1,3-二氧化物。含有亲核杂环取代基的3 H -2,1,4-苯并恶二嗪4-氧化物对日光的稳定性更高,可用作光致变色化合物。