Sulfonated Reduced Graphene Oxide (RGO-SO3H): As an Efficient Nanocatalyst for One-Pot Synthesis of 2-Amino-3-cyano-7-hydroxy-4H-chromenes Derivatives in Water

Sulfonated reduced graphene oxide (RGO-SO₃H) was found to be an efficient catalyst for one-pot synthesis of a class of 2-amino-3-cyano-7-hydroxy-4H-chromenes derivatives using multicomponent reaction (MCR) of phenols, aldehydes and malononitrile under mild and green conditions. The reaction was performed in water as a green solvent and range of 2-amino-3-cyano-7-hydroxy-4H-chromenes were obtained in good to excellent yields. The RGO-SO₃H was reusable at least 5 times without significant decrease in its catalytic activity.