Brønsted acid functionalized carbon catalyst for synthesis of biologically active coumarin-substituted bis(indolyl)methanes

Abstract

Abstract A novel carbon based catalyst has been prepared for the synthesis of potential anticancer compounds with low toxicity by an ionic liquid assisted doping process. Sulphonic acid functionalized nitrogen sulphur co-doped graphite (SO3H-NSG) based catalyst was prepared by coating the carbon surface with the sulphonic acid bearing ionic liquid and annealing the resulting compound. X-ray photoelectron spectroscopy revealed the successful doping of nitrogen and sulphur atoms in the graphitic matrix and the functionalization of the surface with sulphonic acidic sites. The catalyst was used for the synthesis of biologically active coumarin-substituted bis(indolyl)methanes that were finally evaluated for their toxicity and anticancer properties. The cytotoxicity results unveiled that the iodo derivative of the coumarin-substituted bis(indolyl)methanes showed best anti-cancer activity among the four derivatives synthesized.