Synthesis of new 7-(substituted)amino-1-alkyl-2-aryl-1H-2,3-dihydroimidazo[1,2-a]py rimidin-5- ones bearing the 4-arylpiperazin-1-yl moiety connected by ethyl or acetoyl two-carbonyl chain extension was described. The arylpiperazinyl moiety was introduced by alkylation or acylation with corresponding halogeno-derivatives. Preliminary pharmacological screening showed the 7-(substituted)-amino derivatives of the system investigated to exhibit the CNS activity lesser than that of the 7-amino derivatives and to have no effect on the serotonin neurotransmission pathway.