By condensating ethyl pyruvate with 4-dialkylaminoalkyl-5-aminopyrimidine, obtained by hydrogenolysis of the corresponding 6-chloroderivatives, were prepared 3-methyl-6,8-diazaquinoxalinee-2(1H)-ones which carry on position 1 a tert-aminoalkyl chain (dimethylaminoethyl-, morpholinylethyl-, dimethylaminopropyl- and N-methylpiperazinylpropyl-). The synthetized compounds were tested to verify the effects on acquisition and modification of a conditioned avoidance response (C.A.R.) in rats. In these tests 1-dimethylaminoethyl-3-methyl-6,8-diazaquinoxalin-2(1H)-one, shows activity comparable with that of the cloropromazine.