An efficient and rapid synthesis of 3-hydroxy-3-alkyl-2-oxindoles via Zn-mediated barbier-type reaction under aqueous conditions

Abstract

A robust and rapid synthesis of 3-hydroxy-3-alkyl-2-oxindoles from isatins is described. This method introduces an ecofriendly, un-activated Zn dust, solid $$\hbox {NH}_{4}\hbox {Cl}$$ and substrates under aqueous conditions, which has produced the product in moderate to good yields. Without using column chromatography, majority of the compounds were isolated in analytically pure form. The progress of the reaction could be visualized by naked eye. SYNOPSIS A robust and rapid synthesis of 3-hydroxy-3-alkyl-2-oxindoles from isatins is described. This method introduces an ecofriendly method using un-activated Zn dust, solid $$\hbox {NH}_{4}\hbox {Cl}$$ and substrates under aqueous conditions, which has produced the products in moderate to good yields.