Pyrimidinylpiperazine
1-(2-Pyrimidinyl)piperazine (1-PP, 1-PmP) is a chemical compound and piperazine derivative. It is known to act as an antagonist of the α-adrenergic receptor (K = 7.3–40 nM) and, to a much lesser extent, as a partial agonist of the 5-HT receptor (K = 414 nM; E = 54%). It has negligible affinity for the dopamine D, D, and D receptors (K > 10,000 nM) and does not appear to have significant affinity for the α-adrenergic receptors. Derivatives. A number of pyrimidinylpiperazine derivatives are drugs, including: The anxiolytics are also classified as azapirones due to  the azaspirodecanedione moiety in their structures. 1-PP is a common metabolite of most or all of the listed agents. Alnespirone, binospirone, and enilospirone, despite being azapirones, are not piperazines and therefore do not metabolize to 1-PP, and while perospirone and tiospirone are piperazines, they are instead benzothiazole-substituted piperazines and do not metabolize to 1-PP either.