Barbituric Acid: A Green And Efficient Organocatalyst For The Synthesis of 1,8-dioxo-octahydroxanthenes Under Solvent-Free Conditions

A simple, direct and efficient method for synthesis of 1,8-dioxo-octahydroxanthenes by condensation of various aromatic aldehydes with 5,5-dimethyl-1,3-cyclohexanedion (dimedone) under solvent-free conditions using barbituric acid as an organocatalysis is described. Barbituric acid or malonylurea or 6-hydroxyuracil is an organic compound based on a pyrimidine heterocyclic skeleton. It is an odorless powder soluble in water. Barbituric acid is the parent compound of barbiturate drugs. The development the method has several merits such as high yields, short reaction times, simple work-up and use of easily available, cheap and environmentally benign organocatalysis. The structures of products were confirmed from the analysis of their IR, 1H-NMR, melting points.

Keywords:

1 , 8-dioxo-octahydroxanthenes , barbituric acid , solvent-free conditions , 5 , 5-dimethyl-1 , 3-Cyclohexanedion , aromatic aldehydes