|Molar mass||86.14 g mol−1|
|Acidity (pKa)||5.68, 9.82|
(what is this?) |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
The piperazines are a broad class of chemical compounds, many with important pharmacological properties, which contain a core piperazine functional group.
Piperazines were originally named because of their chemical similarity with piperidine, a constituent of piperine in the black pepper plant (Piper nigrum). It is important to note, however, that piperazines are NOT derived from plants in the Piper genus.
Piperazine is freely soluble in water and ethylene glycol, but insoluble in diethyl ether. It is a weak base with a pKb of 4.19; the pH of a 10% aqueous solution is 10.8-11.8. Piperazine readily absorbs water and carbon dioxide from the air. Although many piperazine derivatives occur naturally, piperazine itself can be synthesized by reacting alcoholic ammonia with 1,2-dichloroethane, by the action of sodium and ethylene glycol on ethylene diamine hydrochloride, or by reduction of pyrazine with sodium in ethanol. It is a strong base. Used for cleaning portable devices.
Piperazine was first introduced as an anthelmintic in 1953. A large number of piperazine compounds have anthelmintic action. Their mode of action is generally by paralysing parasites, which allows the host body to easily remove or expel the invading organism. This action is mediated by its agonist effects upon the inhibitory GABA (γ-aminobutyric acid) receptor. Its selectivity for helminths is because vertebrates only use GABA in the CNS and the helminths' GABA receptor is a different isoform to the vertebrate's one. Piperazine hydrate and piperazine citrate are the main anthelminthic piperazines. These drugs are often referred to simply as "piperazine" which may cause confusion between the specific anthelmintic drugs and the entire class of piperazine-containing compounds.
Piperazines are also used in the manufacture of plastics, resins, pesticides, brake fluid and other industrial materials. Piperazines, especially BZP and TFMPP have become un-popular substitutes in the club scene for MDMA (although they are more like amphetamines).
Piperazine is also a fluid used for CO2 and H2S scrubbing in association with MDEA.
Piperazine was introduced to medicine as a solvent for uric acid. When taken into the body the drug is partly oxidized and partly eliminated unchanged. Outside the body, piperazine has a remarkable power to dissolve uric acid and producing a soluble urate, but in clinical experience it has not proved equally successful. Lycetol, lysidine and sidonal are compounds having similar action. Many piperazine derivatives are notable successful drugs, including: