A simple and catalyst-free three-component method for the synthesis of spiro[indenopyrazolopyridine indoline]diones and spiro[indenopyridopyrimidine indoline]triones

An efficient, simple and catalyst-free synthesis of spiro[indeno[1,2-b]pyrazolo[4,3-e]pyridine indoline]diones and spiro[acenaphthylene-indeno[1,2-b]pyrazolo[4,3-e]pyridine]diones by the three-component reaction of 1,3-indandione, pyrazol-5-amines and isatins or acenaphthylene-1,2-dione in refluxing ethanol is reported. Reaction of 2,6-diaminopyrimidin-4(3H)-one with 1,3-indandione and isatins resulted in the formation of 1H-spiro[indeno[1,2-b]pyrido[2,3-d]pyrimidine-5,3′-indoline]-2′,4,6(11H)-triones.