Hantzsch reaction with bis-indole-2,3-diones: Synthesis of novel bis-spirocyclic oxindole incorporating acridine, dipyrazolo[3,4-b:4',3'-e]pyridine and pyrido[2,3-d:6,5-d']dipyrimidine

One-pot three-component cyclo-condensation reaction of bis(indole-2,3-diones) with dimedone, 3-methyl-1H-pyrazol-5(4H)-one, or 6-aminouracil in boiling acetic acid afforded bis-spirocyclic oxindole...