A simple synthesis of N-aryl-3-aminodihydropyrrol-2-one-4-carboxylates via one-pot multi-component reaction of amines, dialkyl acetylenedicarboxylates and formaldehyde in the presence of oxalic acid dihydrate (20 mol%) as catalyst in methanol is described. This homogeneous catalytic procedure offers advantages including mild reaction conditions, good to high yields, short reaction time, simple and readily available starting materials, easy work-up and there is no need for column chromatography.