Grindstone chemistry: one-pot synthesis of spiro[diindenopyridine-indoline]triones and spiro[acenaphthylene-diindenopyridine]triones

A one-pot, pseudo four-component, and simple synthesis of spiro[diindenopyridine-indoline]triones and spiro[acenaphthylene-diindenopyridine]triones via the reaction of 1,3-indandione, aromatic amines and isatins or acenaphthylene-1,2-dione using a 'Grindstone Chemistry' method is reported.