ZnCl2-catalyzed three-component coupling reaction involving a variety of functionalized enamines, triethyl orthoformate, and ammonium acetate, which leads to the production of 4,5-disubstituted pyrimidinederivatives in a single step. The procedure can be successfully applied to the efficient synthesis of mono- and disubstituted pyrimidinederivatives, using methyl ketone derivatives instead of enamines