Acid catalyzed Knoevenagel condensation of thiobarbituric acid and aldehyde at room temperature

Knoevenagel reactions have been performed by the action of various unsymmetrical thiobarbituric acids containing activated methylene carbon and electron deficient center of aromatic aldehydes using small amount of acetic acid as initiator in ethanolic medium. The present protocol proceeded smoothly on room temperature stirring using ethyl alcohol as solvent with the help of initiator. The work-up procedure is very simple and products have been purified by simple recrystallization. Thus rendering the methodology is good and all synthesized molecules were characterized by H-1, C-13 NMR, and MS spectra.