DMF mediated Henry reaction of isatins: an efficient synthesis of 3-hydroxy-2-oxindole

Abstract An efficient Henry reaction has been described for the synthesis of 3-hydroxy-3-(nitroalkyl)-2-oxindole by the reaction of isatins with nitroalkanes in N,N-dimethylformamide (DMF) under anhydrous condition. This method provides high yield of 3-hydroxy-2-oxindoles under mild reaction condition. Moreover, the procedure is environmentally benign in nature, efficient, and applicable to variety of isatins as well as nitroalkanes.