Competition between ethylenic and nitrile groups in the intramolecular capture of nitrile imines
Abstract
o-Vinylphenylhydrazonyl chlorides (2) react with triethylamine in boiling benzene to afford cyclopropa-[c]cinnolines (4) and [1,2,4]triazolo[1,5-a]quinolines (5). Under the same conditions, the structurally related compounds (7) give 1,2-benzodiazepines (10). A mechanism is proposed involving nitrile imine intermediates which cyclise through participation of the nitrile or ethylenic group.