Bis(indoline-2,3-diones): versatile precursors for novel bis(spirooxindoles) incorporating 4$H$-chromene-3-carbonitrile and pyrano[2,3-$d$]pyrimidine-6-carbonitrile derivatives

Multicomponent reaction of dimedone or 1,3-dimethylbarbituric acid and malononitrile with a series of bis(indoline-2,3-diones) afforded the corresponding bis(2-amino-7,7-dimethyl-2',5-dioxo-5,6,7,8-tetrahydrospiro[chromene-4,3'-indoline]-3-carbonitrile) and bis(7'-amino-1',3'-dimethyl-2,2',4'-trioxo-1',2',3',4'-tetrahydrospiro[indoline-3,5'-pyrano [2,3-d]pyrimidine]-6'-carbonitrile) derivatives in good to excellent yield.