Piperazine

Piperazine
File:Piperazine structure.svg	File:Piperazine-3D-balls-B.png
IUPAC name piperazine
Other names Hexahydropyrazine Piperazidine Diethylenediamine
style="background: #F8EABA; text-align: center;" colspan="2" | Identifiers
CAS number	110-85-0 Y
PubChem	4837
ChemSpider	13855459
ATC code	P02CB01
SMILES
style="background: #F8EABA; text-align: center;" colspan="2" | Properties
Molecular formula	C4H10N2
Molar mass	86.14 g mol−1
Melting point	106°C
Boiling point	146°C
Acidity (pKa)	5.68, 9.82
style="background: #F8EABA; text-align: center;" colspan="2" | Pharmacology
Protein binding	60-70%
style="background: #F8EABA; text-align: center;" colspan="2" | Hazards
NFPA 704	75px 2 2 0
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Piperazine is an organic compound that consists of a six-membered ring containing two opposing nitrogen atoms. Piperazine exists as small alkaline deliquescent crystals with a saline taste.

The piperazines are a broad class of chemical compounds, many with important pharmacological properties, which contain a core piperazine functional group.

Origin and naming

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.

Chemistry

Piperazine is freely soluble in water and ethylene glycol, but insoluble in diethyl ether. It is a weak base with a pK_b 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.

As an anthelmintic

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.

Other uses

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 (due to their similarity in effect to amphetamines like MDMA).

Piperazine is also a fluid used for CO₂ and H₂S scrubbing in association with methyl diethanolamine (MDEA).

Piperazine derivatives as drugs

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:

Antianginals

• Ranolazine
• Trimetazidine

Antidepressants

• Alnespirone
• Amoxapine
• Befuraline
• Binospirone
• Buspirone
• Flesinoxan
• Gepirone
• Ipsapirone
• Nefazodone
• Piberaline
• Tandospirone
• Trazodone
• Vilazodone
• Zalospirone

Antihistamines

• Buclizine
• Cetirizine
• Cinnarizine
• Cyclizine
• Hydroxyzine
• Levocetirizine
• Meclizine
• Niaprazine

Antipsychotics

• Typical
  • Flupentixol
  • Fluphenazine
  • Perphenazine
  • Prochlorperazine
  • Thiothixene
  • Trifluoperazine
  • Zuclopenthixol
• Atypical
  • Amperozide
  • Aripiprazole
  • Clozapine
  • Lurasidone
  • Olanzapine
  • Perospirone
  • Ziprasidone

Recreational Drugs

• 4-Bromo-2,5-dimethoxy-1-benzylpiperazine (2C-B-BZP)
• 1-Benzylpiperazine (BZP)
• 2,3-Dichlorophenylpiperazine (DCPP)
• 1,4-Dibenzylpiperazine (DBZP)
• 4-Methyl-1-benzylpiperazine (MBZP)
• 3-Chlorophenylpiperazine (mCPP)
• 3,4-Methylenedioxy-1-benzylpiperazine (MDBZP)
• 4-Methoxyphenylpiperazine (MeOPP)
• 4-Chlorophenylpiperazine (pCPP)
• 4-Fluorophenylpiperazine (pFPP)
• 3-Trifluoromethylphenylpiperazine (TFMPP)

Urologicals

• Sildenafil
• Vardenafil

Others

• 6-Nitroquipazine
• Antrafenine
• Fipexide
• Imatinib
• Piperazine (itself)
• Quipazine

Most of these agents can be classified as either phenylpiperazines, benzylpiperazines, diphenylmethylpiperazines (benzhydrylpiperazines), pyridinylpiperazines, pyrimidinylpiperazines, or tricyclics (with the piperazine ring attached to the heterocyclic moiety via a side chain).

See also

• Pyridine
• Piperidine

References

• 12px This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed (1911). "Piperazin". Encyclopædia Britannica (11th ed.). Cambridge University Press. 

External links

• Erowid piperazine vault
• Piperazine Reviews and Information

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