Synthesis of isatin derivatives employing ZnO-NPs and diethyl oxalate

We report on the preparation of a series of isatins in the presence of ZnO-nanorods as the catalyst in water. These biologically important compounds were prepared via a condensation reaction of anilines with diethyl oxalate. The use of inexpensive and reusable catalyst in water, and with easier isolation of the products in high yields makes this protocol eco-friendly and versatile compared to the existing procedures.