Reaction of 6-aminouracils with aldehydes in water as both solvent and reactant under FeCl<sub>3</sub>·6H<sub>2</sub>O catalysis: towards 5-alkyl/arylidenebarbituric acids
5-Alkyl/arylidenebarbituric acids were efficiently synthesized through an FeCl3·6H2O catalyzed domino reaction of 6-aminouracils, water and aldehydes with water serving a dual role as both solvent and reactant, under benign conditions.