A ONE POT THREE-COMPONENT SYNTHESIS OF SPIROOXOINDOLES USING Cu-NANOPARTICLES GRAFTED ON CARBON MICROSPHERES AS CATALYST

Abstract

The copper nanoparticles grafted on carbon microsphere is employed for an efficient one-pot three-component synthesis of spirooxoindole derivatives involving isatin, malononitrile and enolizable ketones such as 3-methyl-1-phenyl-2-pyrazolin-5-one, 3-methyl-1-(2chlorophenyl)-2-pyrazoline 5-one, 4-hydroxy-6-methyl-2-pyrone and 1-methyl-4-hydroxyquinoline-2-one. The cheap starting material, easy separation, high catalytic efficiency and reusability of the catalyst for several times without loss of its efficiency, good yield of products, and simple workup are promising features of the reaction in 1:1 (v/v) aqueous-alcoholic medium.

Recent update on synthesis of spiro-heterocycles in alcohol using malononitrile as a building block

“…Pawar et al also independently developed 44 a multi-component methodology to synthesize pyran containing spiro-oxindole derivatives using malononitrile, enolizable ketones and isatins in (1:1) aqueous ethanol solvent under the catalytic influence of Cu nanoparticles embeded on carbon microsphere under reflux.…”

Palladium and Copper: Advantageous Nanocatalysts for Multi-Step Transformations

“…A simple procedure for the syn-Scheme 43. CuNPs catalyzed the synthesis of heterocycles [175,180,181,[183][184][185].…”

“…PXRD evidenced the presence of merely crystalline Cu(0), while Raman spectroscopy and SEM both exhibited resin carbonization. Pawar and co-workers employed the same catalyst for a three-component synthesis of spirooxoindole derivatives ( Scheme 43 ) [ 181 ]. Actually, more than 20 compounds were prepared in ethanol/water reflux, achieving high yields (>86%) in less than 60 min.…”