Synthesis of spiro[pyrazolo[3,4-b] pyridine-4,3′-indoline] and spiro [benzo[h]pyrazolo[3,4-b]quinoline-4,3′-indoline] derivatives using wet cyanuric chloride under solvent-free conditionS

Abstract

A simple and efficient synthesis of spiro[pyrazolo[3,4-b]pyridine-4, 3′-indoline] and spiro[benzo[h] pyrazolo[3,4-b]quinoline-4,3′- indoline] derivatives has been accomplished by the one-pot condensation of isatins, 3-methyl-1-phenyl-1H-pyrazol-5- amine and Meldrum's acid or 2-hydroxy-1,4-naphthoquinone in the presence of wet cyanuric chloride as a catalyst under solvent-free conditions. [Figure not available: see fulltext.] © 2013 Indian Academy of Sciences.