Eco-friendly polyethylene glycol (PEG-400): a green reaction medium for one-pot,four-component synthesis of novel asymmetrical bis-spirooxindole derivatives at room temperature

PEG-400 has been used as a green and biodegradable polymeric solvent for the one-pot, two-step, multi-component synthesis of novel asymmetrical bis-spirooxindole derivatives by the reaction of N-alkyl isatin, isatin derivatives, alkylmalonates and C–H activated carbonyl compounds in the presence of K₂CO₃ at room temperature. Using this procedure, all the products were obtained in good to excellent yields.

PEG-400 has been used for the synthesis of novel asymmetrical bis-spirooxindoles by the reaction of N-alkyl isatin, isatin derivatives, alkylmalonates and C–H activated carbonyl compounds in the presence of K₂CO₃ at room temperature.