Efficient One-Pot Synthesis of Spiro[Indoline-3,11'-Pyrazolo[3,4-a]Acridine]-2,10'(1'H)-Dione Derivatives Catalyzed by L-Proline

An efficient eco-friendly procedure for the synthesis of spiro[indoline-3,11'-pyrazolo[3,4-a]acridine]-2,10'(1'H)-dione derivatives has been developed through a one-pot three-component condensation of 1H-indazol-6-amine, isatin, and 5,5-dimethyl cyclohexane-1,3-dione or cyclohexane-1,3-dione, in the presence of catalytic amount L-proline in EtOH at 60 degrees C conditions. The advantages of this protocol include mild reaction condition, green, and nontoxic solvent, high yield, and operational simplicity. IR, H-1 NMR, C-13 NMR, HRMS spectras, and elemental analyses were used to identify the structures of all the synthesized compounds.

Automated summary

An efficient and eco-friendly procedure for the synthesis of unique spiro[indoline-3,11'-pyrazolo[3,4-a]acridine]-2,10'(1'H)-dione derivatives has been developed through a one-pot reaction using ethanol as solvent and catalytic amount of L-proline. This method offers advantages such as mild reaction conditions, high yield, and simplicity.