Heterocyclic compounds with bridgehead nitrogen atoms. Part IV. Cyclopenta[ij]pyrido[2,1,6-de]quinolizines (cyclopenta[cd]cycl[3,3,3]-azines)

Abstract

Cyclopenta[c]quinolizines react with αβ-acetylenic esters to give cyclopenta[ij]pyrido[2,1,6-de]quinolizines (cyclopenta[cd]cycl[3,3,3]azines). The ¹H n.m.r. spectra of the latter show evidence of aromatic character. Protonation of a dimethylcyclopentacyclazine occurred at the 1-position and treatment with benzoyl chloride gave a 1-benzoyl derivative. Other electrophilic reagents caused decomposition.