Microwave assisted catalyst-free synthesis of azaarene-substituted 3-hydroxy-2-oxindoles by the functionalization of sp3 C–H bond in methyl pyridine

A highly efficient synthesis of azaarene-substituted 3-hydroxy-2-oxindoles in catalyst-free conditions is described by the reaction of 2-methyl pyridines with isatins under microwave irradiation in aqueous medium. Simple reaction conditions, high yields of the products and environmentally benign medium are attractive features of the present protocol.