Abstract

Background: Now a day’s green synthesis for multicomponent reactions is a powerful tool for construction of five membered/six membered heterocyclic ring systems. The synthesis of regio and stereoselective complex architectural motifs following 1,3-dipolar cycloaddition reactions via ecofriendly methods are well reported. The synthesis of pyrrolidine/piperidine based heterocycles has been the center of attraction because of their pronounced biological activities.

Methods: The present methodology deals with one pot three component cycloaddition reaction of isatin based azomethine ylide and substituted nitrochromene to synthesize new spirooxindole-pyrrolidine/piperidine fused nitrochromanes in refluxing ethanol within 2 hr.

Results: A series of new spirooxindole-pyrrolidine/piperidine fused nitrochromanes were synthesized in good to excellent yield (78-89%) via one pot three component cycloaddition reactions. The obtained products were isolated in good yield by simple filtration. All the synthesized compounds were well characterized (¹H, ¹³C, Mass and M.P). The regio/ stereochemical results were ascertained by X-ray crystallographic study.

Conclusion: We have developed an ecofriendly method to synthesize twelve new and novel spirooxindolepyrrolidine/ piperidine fused nitrochromanes via one pot three component 1,3-dipolar cycloaddition reaction in nontoxic solvent in a shorter time. It offers several advantages such as regio/stereoselective synthesis of spirooxindolepyrrolidine/ piperidine fused nitrochromanes, shorter reaction time, mild reaction conditions, simple and environmentally friendly operational procedure.

Keywords: Isatin, 1, 3-dipolar cycloaddition reaction, heterocycles, spirooxindole, piperidine, pyrrolidine.

Graphical Abstract