Abstract New tetracyclic systems containing a pyrrolobenzodiazepine 5 or a pyrrolobenzotriazepine 6 moiety bounded by a spiro linkage to the piperidine nucleus are described. They have been synthesized by a simple reaction involving the interaction between proper aromatic amines and 4-oxopiperidines substituted or not at the 1-position in the presence of maleic acid as a catalyst. The synthesis of spiropyrrolo [1, 2-a] quinoxaline ...
