One-Pot Synthesis of Spiro[diindeno[1,2-b:2′,1′-e]pyridine-11,3′-indoline]-triones

A one-pot and pseudo four-component synthesis of spiro[diindeno[1,2-b:2',1'-e]pyridine-11,3'-indoline]-trione derivatives by cyclo-condensation reaction of isatins, 1,3-indandione, and ammonium acetate in refluxing acetic acid is reported.