The reaction of ethyl 3,3-diaminoacrylate with quinoline-3-carbaldehydes and 3-nitrobenzaldehydes to give a dihydropyridine and condensed azine has been studied with respect to the number and reactivity of the halogen atoms in an ortho position to the formyl groups. For the series of quinoline-3-carbaldehydes it was found that the reaction course is determined by the number of chlorine atoms. 2-and 4-Chloroquinoline-3-carbaldehydes give dihydropyridines and a benzo[c][2,7-]naphthyridine is formed in the reaction with 2,4- dichloroquinoline-3-carbaldehyde. The main products in the case of nitrobenzaldehydes are dihydropyridines which points the deciding influence of the low electrophilicity of aromatic ring.