The reaction of anilines, benzaldehydes, and ethyl 3, 3-diethoxypropionate in the presence of Yb (OTf) 3 proceeded under mild reaction conditions to give dihydropyridines (DHPs). We have found that the reaction depended on the solvent and the DHPs were obtained selectively in 1, 4-dioxane as a solvent. Various 2, 6-unsubstituted DHPs were synthesized in one pot in satisfactory yields.