Dipyrimidine-fused pyridine derivatives were synthesized using 1,3-diketone, aldehyde, different ammonium salts, and water, as the solvent. Aromatization was observed when ammonium nitrate was used as the source of nitrogen, and thus, dipyrimidine-fused pyridine derivatives were synthesized in one-pot synthetic procedure. This environmentally benign procedure leads to high yield of products (80%–90%) in a single step, with greater purity using water as the solvent.Key words: water, aromatization, dipyrimidopyridine, ammonium salts.