Reductive cyclization of carbohydrate 2-nitrophenylhydrazones to chiral functionalized 1,2,4-benzotriazines and benzimidazoles
作者:Jens Andersch、Dieter Sicker
DOI:10.1002/jhet.5570360302
日期:1999.5
The 2-nitrophenylhydrazones 2 of D-arabino-2-hexulopyranosonic acid, D-arabinose, D-galactose and D-galacturonic acid are used as precursors to form chiral functionalized 1,2,4-benzotriazines and benzimidazoles by reductive cyclization methods. Catalytic hydrogenation provided the amine derivatives which are cyclized and air oxidized in alkaline solution to yield the novel 1,2,4-benzotriazines 3 as
2- nitrophenylhydrazones 2 D-的阿拉伯-2- hexulopyranosonic酸,d阿拉伯糖,d半乳糖和d半乳糖醛酸被用作前体以形成通过还原环化方法手性官能1,2,4-苯并三嗪类和苯并咪唑类。催化氢化提供了胺衍生物,其在碱性溶液中被环化并被空气氧化,以产生新的1,2,4-苯并三嗪3作为主要产物,而在酸催化下形成了苯并咪唑4。