Highly efficient synthesis of 3-pyrrolyl-indolinones and pyrrolyl-indeno[1,2-b]quinoxalines catalyzed by heteropolyacids

Simple and improved conditions have been found for the synthesis of 3-pyrrolyl-indolinones and pyrrolyl-indeno[1,2-b]quinoxalines by coupling of 4-hydroxyproline with isatins and 11H-indeno[1,2-b]quinoxalin-11-ones using Keggin (H3PW12O40) and Well-Dawson tungsten heteropolyacids (H6P2W18O62).

Simple and improved conditions have been found for the synthesis of 3-pyrrolyl-indolinones and pyrrolyl-indeno[1,2-b]quinoxalines by coupling of 4-hydroxyproline with isatins and 11H-indeno[1,2-b]quinoxalin-11-ones using Keggin (H3PW12O40) and Well-Dawson tungsten heteropolyacids (H6P2W18O62).