Syntheses of 4-Indolylquinoline Derivatives via Reductive Cyclization of Indolylnitrochalcone Derivatives by Fe/HCl

Abstract

An easy and efficient procedure for the synthesis of 4-indolylquinoline derivatives is described. This process involves two steps, the first of which is the Michael addition of indole to nitrochalcones promoted by sulfamic acid under solvent free conditions and the second step is a reductive cyclization of the indolylnitrochalcone intermediates to 4-indolylquinoline derivatives by Fe/HCl in ethanol. In both steps, the reactions are clean and the yields of products are high.

Keywords

• Fe/HCl
• reductive cyclization
• 4-indolylquinoline
• indolylchalcone