Abstract When 1H-2-methyl-1-p-nitrophenyl-3-ethoxycarbonylpyrido [3, 2-b] indole (1) is heated in alcoholic solutions of ammonia, we observe a previously unknown recyclization leading to formation of 2-alkoxycarbonyl-3-methyl-9-p-nitrophenylimino-9H-pyrrolo [1, 2-a] indoles (3, 6).
![ethyl 1-{4-nitrophenyl}-2-methyl-1H-pyrido[3,2-b]indole-3-carboxylate Structure](https://image.chemsrc.com/caspic/178/374697-64-0.png)
![ethyl 1-methyl-4-oxopyrrolo[1,2-a]indole-2-carboxylate Structure](https://image.chemsrc.com/caspic/064/60706-06-1.png)