Synthesis of seven-and eight-membered[1,2-a]alicyclic ring-fused benzimidazoles and 3-aziridinyIazepino[1,2-a]benzimidazolequinone as a potential antitumour agent

摘要

Azepino and azocino[1,2-a]benzimidazoles were obtained either by treatment of 1-nitrophenyl-2-aza-cycloalkanes via a one-pot catalytic hydrogenation/acetylation or by treatment of the acetamides generated in the latter reaction with performic acid.This represents the first facile synthesis of eight-membered[1,2-a]alicyclic ring-fused benzimidazoles.3-Methoxy-azepino[1,2-a]benzimidazole was elaborated to the novel potential cytotoxin,3-(N-aziridinyl)-7,8,9,10-tetrahydro-6H-azepino[1,2-a]benz-imidazole-1,4-dione.The synthesis included clarification of the reactivity of methoxy-substituted benzimidazoles towards nitration.