The Synthesis of Heterocycles from Indolin-2-one Derivatives and Active Methylene Reagents

Abstract

Investigation the synthesis of multifunctionalized heterocyclic spiro derivatives via the reaction of isatin, ethyl cyanoacetate and an other active methylene compound. It has been found that refluxing of an ethanolic piperidine solution of equimolar ratios of isatin (Ia), ethyl cyanoacetate (II) and barbituric acid (IIIa) or thiobarbituric acid (IIIb) afforded a solid product whose structure was assumed, in accordance with elemental analysis and IR and 1H NMR spectra, to be VIIIa and VIIIb. Confirmation of the structures VIIIa and VIIIb follows from their preparation from compound IV, synthesized separately, and barbituric acids IIIa and IIIb in 1 : 1 molar ratio under the same reaction conditions.