Novel 4-(3-nitrophenyl)pyridine and 4-(3-nitrophenyl)pyrimidine derivatives, possessing three-atom linkages between basic nitrogen and at the C-5 (or C-3) position of the pyrimidine (or pyridine) ring, were synthesized and tested for anti-anoxic (AA) activity in mice. Among them, 6-methyl-4-(3-nitrophenyl)-2-phenyl-5-(pyrrolidinomethylcarbonyl-amino)pyrimidine (10f) had the most potent AA activity (3.2 mg/kg, i.p.). Three-dimensional molecular electrostatic potentials (3D-MEP) around the nitrogeneous basic moiety of 6-methyl-5-(4-methylpiperazin-1-ylcarbonyl)-4-(3-nitrophenyl)-2-phenylpyrimidine (FK 360) and 10f were compared. The negative zone of 10f is broader and deeper and positioned somewhat differently to that of FK 360, although there is a co-occupied spacial area in part.