Synthetic routes to benz- and naphth-indenoquinolines

Abstract

The Mannich base formed in situ from indane-1,3-dione, formaldehyde, and piperidine reacted with 1- and 2-naphthylamines in acetic acid to give 7-oxobenz[h]- and 9-oxobenz[f]-indeno[2,1-c]quinolines. Indan-1,3-dione and 2-naphthylamine gave 3-(2-naphthylimino)indan-1-one, converted by treatment with aromatic aldehydes into 13-aryl-12-oxobenz[f]indeno[1,2-b]quinolines. 1-Naphthylamine and 2-anthrylamine similarly gave 7-aryl-8-oxobenz[h]- and 14-aryl-13-oxonaphth[2,3-f]-indeno[1,2-b]quinolines, respectively. The Mannich bases 2-arylaminomethyl-N-(3-oxoinden-1-yl)indane-1,3-dione were isolated from the reaction product of indane-1,3-dione and formaldehyde with aromatic amines.