An improved method for the reaction of 2,4-dichlorothiazole-5-carbaldehyde (2) with secondary amines was established using potassium carbonate in acetonitrile at room temperature instead of deprotonation with butyllithium in tetrahydrofuran at −78°. The method is convenient and the yields of 3 even higher. Compound 2 could also be reacted by this method with thiophenols to yield 4-chloro-2-phenylt