FeCl3-catalyzed three-component reaction: a novel synthesis of tetrahydro-2,6-dioxopyrimidin-4-yl-2,3-dihydrophthalazine-1,4-dione derivatives under solvent-free conditions

Three-component coupling of phthalhydrazide, aldehydes, and barbituric acid has been accomplished in the presence of 15 mol % FeCl₃ under solvent-free conditions to afford the corresponding tetrahydro-2,6-dioxopyrimidin-4-yl)-2,3-dihydrophthalazine-1,4-dione derivatives in excellent yields. This method provides high yields, shorter reaction time, and mild reaction conditions. This is the first example of the condensation of phthalhydrazide, aldehydes, and barbituric acid to provide a novel series of phthalhydrazide derivatives.