| Abstract: | Two new tetracyclic structures, containing the diazepine ring, were synthesized: 5,6-dihydro-12H-benzofuro[3,2-b][1,5]benzodiazepin-6-one and 5,6-dihydro-12H-benzofuro[3,2-b]pyrido[3,2-f][1,5]diazepin-6-one. Thus N-(2-haloaryl)-2-[(2-cyanophenyl)oxy]acetamides were cyclized to the corresponding N-(2-haloaryl)-3-amino-2-benzofurancarboxamides and then, through the formation of the central diazepine ring, to the title compounds. Formation of the diazepine ring took place only when an electron-withdrawing group was present in the molecule to facilitate the nucleophilic attack of an amine in the benzofuran intermediate. |
