Facile Synthesis of 3-Hydroxy Oxindole by a Decarboxylative Aldol Reaction of β-Ketoacid and Isatin in WERSA

Facile synthesis of bioactive 3-hydroxy-oxindole by decarboxylative aldol reaction via in-situ generated methyl enolate of beta-ketoacid and isatin in Water Extract of Rice Straw Ash (WERSA) is described. This method provides clean, simple and useful alternative to synthesize 3-hydroxy-oxindole. The products were isolated in excellent yield without using column chromatography. The green chemistry matrices calculated, and it also shows green protocol used.