One-pot three-component reaction for the synthesis of biologically important spiro[benzo[f]quinoline-3,3′-indoline] derivatives

A previously unknown class of highly substituted benzoquinoline–spirooxindole are easily prepared by a novel application of a mild and efficient catalyst SbCl₃ for carbon–carbon and carbon–nitrogen bond formation reaction involving isatin, alkyne (dialkyl but-2-ynedioate) with aromatic amine (2-naphthylamine) in a one-pot three-component reaction. This protocol of one-pot synthesis afforded a library of dialkyl 2′-oxo-4H-spirobenzof]quinoline-3,3′-indoline]-1,2-dicarboxylate derivatives, a potential bioactive compound in very good to excellent yields.