Some analogues of 1,4-disubstituted piperazines as hypnotic and sedative agents. 
Preparation, analytical data, and biological properties such as acute toxicity, influence on spontaneous and amphetamine induced locomotor activity, hypnotic activity, influence on hexobarbital narcosis and anticonvulsant activity of new analogues of pyrimidyl piperazines--ethyl 3-[4-(2-pyrimidyl)-1-piperazinyl]-3-oxopropanoate (4), 1-[4-(2-pyrimidyl)-1-piperazinyl]-1,3-butandione (5), ethyl 3-[4-(2-pyrimidyl)-1-piperazinyl]butanoate (6) and 1-[4-(2-pyrimidyl)-1-piperazinyl]-2-acetyl-1-hexanone (7)--are reported.