2-(1-Piperazinyl)pyrimidine is an antagonist of α2-adrenergic receptors (α2-ARs; pA2 = 6.8 in rat brain synaptosomes) and active metabolite of various azapirones, including buspirone. It is formed from buspirone by the cytochrome P450 (CYP) isoform CYP3A4 in human liver microsomes. 2-(1-Piperazinyl)pyrimidine inhibits decreases in gastrointestinal transit induced by clonidine in rats (ED50 = 0.8 mg/kg). It increases drinking in the Vogel punished drinking task, indicating anxiolytic-like activity, in rats when administered at doses ranging from 1 to 4 mg/kg.2-(1-Piperazinyl)pyrimidine (0.25-1 mg/kg) also reduces the amplitude of electrically stimulated excitatory post-synaptic potentials (EPSPs) in the hippocampal CA1 region in rats, an effect that can be blocked by the serotonin (5-HT) receptor subtype 5-HT1A antagonist spiroxatrine. It has also been used a phosphopeptide derivatization agent.