Pyrimidinylpiperazine

1-(2-Pyrimidinyl)piperazine (1-PP, 1-PmP) is a chemical compound and piperazine derivative. It is known to act as an α₂-adrenergic receptor antagonist, and as a 5-HT_1A receptor partial agonist to a much lesser extent. It does not appear to have any significant affinity for the D₂ or α₁-adrenergic receptors.

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.