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. (C) 2012 Elsevier Ltd. All rights reserved.