4,5-Dihydropyridines bearing an N,N-disubstituted amino group in the 2-position, carbonyl functions in the 3- and 5-positions and being optionally substituted in the 6-position by lower alkyl or phenyl and, in the 4-position by lower alkyl, phenyl, substituted phenyl or a heterocyclic group, are antihypertensive agents and coronary vessel dilators. The compounds, of which 2-pyrrolidino-6-methyl-4-(3-nitrophenyl)-4,5-dihydropyridine-3,5-dicarboxy lic acid 3,5-diethyl ester is a representative embodiment, are prepared through condensation of an ylideneacetoacetic acid ester and a substituted 3,3-diaminoacrylate.