Research on nitrogen heterocyclic compounds. XII. Synthesis of 5H-pyrrolo[1,2-b][2]benzazepine derivatives

Several routes to the synthesis of the unknown 5H-pyrrolo1,2-b]2]benzazepine ring system have been explored. 1-(2-Cyanobenzyl)pyrrole was useful as starting material to obtain 1-(2-earboxymelhylbenzyl)pyrrole and 1-(2-chloromethylbenzyl)-2-pyrrolecarboxaldehyde. Poly-phosphoric acid catalyzed intramolecular cyclization of the former substance and treatment of the latter compound with potassium cyanide led to 11-oxo-10,11-dihydro-5H-pyrrolo1,2-b]-2]benzazepine and to 10-cyano-5H-pyrrolo1,2-b]2]benzazepine, respectively. Starting from these materials the synthesis of the parent nucleus 5H-pyrrole1,2-b]2]benzazepine and its 10,11-dihydro- and 1,2,3,10,11,11a-hexahydroderivatives has been realized.