New Synthesis of Diazepino[3,2,1‐ij]quinoline and Pyrido[1,2,3‐de]quinoxalines via Addition–Elimination Followed by Cycloacylation

This paper describes a convenient and efficient synthesis of new fused tricyclic diazepino[3,2,1‐ ij ]quinolines and substituted pyrido[1,2,3‐ de ]quinoxalines. o ‐Phenylenediamines are transformed in the tricycle nucleus in only a few‐step synthetic sequence to produce ethyl 2,8‐dioxo‐1,2,3,4‐tetrahydro‐8 H [1,4]diazepino[3,2,1‐ ij ]quinoline‐7‐carboxylate, ethyl 8‐oxo‐1,2,3,4‐tetrahydro‐8 H ‐[1,4]diazepino[3,2,1‐ ij ]quinoline‐7‐carboxylate and ethyl 2,7‐dioxo‐2,3‐dihydro‐1 H ,7 H ‐pyrido[1,2,3‐ de ]quinoxaline‐6‐carboxylate. The method is economical and simple to perform.