The following new derivatives of pyrido [2,3-d]-pyrimidin-4(3H)-one were synthesized: 3-(2-N,N-dimethylaminoethyl), 3-(2-N-pyrolidynylethyl), 3-(2-piperidinylethyl) and 3-(2-N-morpholidinylethyl). Their chemical structures were confirmed by MS, IR and 1H NMR spectroscopic data. Newly synthesized compounds were investigated pharmacologically for their central properties in mice and rats. It was shown that compound [III] showed anxiolytic action in the four-plate test and two compounds produced analgesic effects in mice.