Piperazine CAS 110-85-0

Introduction：Basic information about Piperazine CAS 110-85-0, including its chemical name, molecular formula, synonyms, physicochemical properties, and safety information, etc.

Piperazine Basic information

• Product Name: Piperazine
• Synonyms: PIPERAZINE;1,4-DIAZACYCLOHEXANE;AKOS 90646;AKOS BBS-00004315;HEXAHYDRO-1,4-DIAZINE;HEXAHYDROPYRAZINE;DIETHYLENEDIAMINE;Anhydrous Piperazine (PIP)
• CAS: 110-85-0
• MF: C4H10N2
• MW: 86.14
• EINECS: 203-808-3
• Product Categories: Organics;blocks;BuildingBlocks;Thiazolines/Thiazolidines;API Intermediate;Heterocycles;Isotope Labelled Compounds;K00001
• Mol File: 110-85-0.mol

Piperazine Chemical Properties

• Melting point: 109-112 °C (lit.)
• Boiling point: 145-146 °C (lit.)
• bulk density: 400kg/m3
• density: 1,1 g/cm³
• vapor pressure: 0.8 mm Hg ( 20 °C)
• refractive index: 1.4460
• FEMA: 4250 | PIPERAZINE
• Fp: 65 °C
• storage temp.: Store below +30°C.
• solubility: H₂O: 0.1 M at 20 °C, clear, colorless
• pka: 9.83(at 23℃)
• form: Crystalline Flakes
• color: White to slightly yellow
• PH: 11.0-12.5 (25℃, 0.1M in H2O)
• Odor: at 0.10 % in dipropylene glycol. ammoniacal
• Odor Type: ammoniacal
• biological source: rabbit
• explosive limit: 14%
• Water Solubility: 150 g/L (20 ºC)
• λmax: λ: 260 nm Amax: 0.035 λ: 280 nm Amax: 0.010
• Sensitive: Air Sensitive & Hygroscopic
• Merck: 14,7464
• JECFA Number: 1615
• BRN: 102555
• Exposure limits: ACGIH: TWA 0.03 ppm
• Stability: Stable. Hygroscopic. Light sensitive. Flammable. Incompatible with strong oxidizing agents.
• InChI: 1S/C4H10N2/c1-2-6-4-3-5-1/h5-6H,1-4H2
• InChIKey: GLUUGHFHXGJENI-UHFFFAOYSA-N
• SMILES: C1CNCCN1
• LogP: -1.24 at 20-25℃
• CAS DataBase Reference: 110-85-0(CAS DataBase Reference)
• NIST Chemistry Reference: Piperazine(110-85-0)
• EPA Substance Registry System: Piperazine (110-85-0)

Safety Information

• Hazard Codes: C,Xn
• Risk Statements: 34-42/43-52/53-62-52-63
• Safety Statements: 22-26-36/37/39-45-61
• RIDADR: UN 2579 8/PG 3
• WGK Germany: 1
• RTECS: TK7800000
• F: 3-8-23
• Hazard Note: Harmful/Corrosive
• TSCA: TSCA listed
• HS Code: 2933 59 95
• HazardClass: 8
• PackingGroup: III
• Storage Class: 4.1B - Flammable solid hazardous materials
• Hazard Classifications: Eye Dam. 1 Flam. Sol. 1 Repr. 2 Resp. Sens. 1B Skin Corr. 1B Skin Sens. 1B
• Hazardous Substances Data: 110-85-0(Hazardous Substances Data)
• Toxicity: LD50 orally in Rabbit: 2600 mg/kg LD50 dermal Rabbit 8300 mg/kg

Piperazine Usage And Synthesis

Important pharmaceutical intermediates

Piperazine is an important pharmaceutical intermediate, is mainly used for the production of anthelmintic piperazine phosphate, piperazine citrate and fluphenazine, strong pain, rifampicin, adipic acid piperazine, piperazine guanidine methyl tetracycline, quinoline piperazine phosphate, piperazine thiazole nitrate, enoxacin, hydroxyzine hydrochloride, trifluoperazine, diethylcarbamazine citrate, cinnarizine, flunarizine, decloxizine strong carbamazepine, prednisolone sodium phosphate, dexamethasone sodium phosphate, PPA, norfloxacin, ciprofloxacin, easy to cough piperazine, a piperazine Lee vancomycin, trimethoprim-triazine and other drugs. It is Also used for the production of surfactants products such as wetting agents, emulsifying agents,and dispersing agents ,and the production of plastic additives such as antioxidants, preservatives, stabilizers and rubber additives. It is derived from Dichloroethane by alcohol solution of ammonia.

Figure 1 The structural formula of piperazine.

Pharmacology and mechanism of action

Piperazine is a heterocyclic organic base widely used as an anthelminthic. It was originally developed for the treatment of gout. Its first successful use in helminthiasis was reported by Mouriquand et al. in 1951 ^[1]. Presently the drug is used in the treatment of infections caused by Ascaris lumbricoides and Enterobius vermicularis.
The drug causes flaccid paralysis in susceptible worms and the parasites lose their attachment to the intestinal wall, and are swept away by the normal bowel peristalsis. The biochemical mechanism behind this action is uncertain. Piperazine causes hyperpolarization of the Ascaris muscle rendering it unresponsive to acetylcholine ^[2].

Indications

Treatment of infections due to Ascaris lumbricoides and Enterobius vermicularis. When cost and availability are not a consideration, safer and more effective drugs such as mebendazole or albendazole should be used instead.

Side effects

Side effects commonly encountered with the recommended doses of piperazine are nausea, vomiting, abdominal cramps and diarrhoea which are usually mild and self-limiting. Although absolute incidence is unknown, severe side effects reported in the literature are rare. They can be classified into:
1. Allergic reactions such as urticaria, exantema, hypersensitivity, lacrimation, rhinorrea, productive cough, and bronchospasm^[3,4].
2. Neuro-psychological reactions^[5-11]:
(a) cerebral type such as vertigo, dizziness, tremor, incoordination, ataxia and hypotonia with EEG changes;
(b) psychic type such as depersonalization, hallucination and paranoic reactions;
(c) miscellaneous such as headache, visual disturbances, somnolence, coma and an increase in the number of petit mal attacks.
Neuro-psychological reactions are rare. Most cases reported concern children with pre disposing factors like neurological symptoms, renal diseases or those who have been treated with high doses of piperazine.
One case of haemolytic anaemia in a patient with G6PD deficiency ^[12], and one case of toxic hepatitis^[13] have also been reported. However, no causal relationships can be established from these cases.
Nitrosation of piperazine to the potential carcinogen N-mononitrosopiperazine in the stomach of patients treated with normal therapeutic doses has been reported^[14]. However, carcinogenicity related to the use of piperazine has not been reported despite the use of the drug over many years. In any case, this is unlikely to have any clinical implications with the short treatment period of nematodes.

Contraindications and precautions

Piperazine should not be given to patients with hypersensitivity or with neurological diseases,especially epileptic patients.

Interactions

In rats and mice, piperazine 1–5 g/kg subcutaneously, potentiates the side effects of chlorpromazine ^[15]. However, this is unlikely to have any clinical significance. Piperazine is antagonistic to pyrantel, bephenium and levamisole , but no potential clinical interactions have been reported.

Preparations

Several preparations, apart from the one mentioned below, containing various piperazine salts are available.
• Antepar® (Wellcome). Oral suspension 150 mg piperazine hexahydrate/ml. Tablets 500 mg piperazine hexahydrate.

Acute oral toxicity

rat LD50: 1900 mg/kg; Oral-Mouse LD50: 600 mg/kg

Data Skin irritation

rabbit 500 mg Mild; Eyes-rabbit 0.25 mg/24 hours of severe

References

1. Mouriquand G, Roman E, Coisnard J (1951). Essai de traitement de l’oxyurose par la piperazine. J Méd Lyon, 32, 189–195.
2. del Castillo J, De Mello WC, Morales T (1964). Mechanism of the paralysing action of piperazine on Ascaris muscle. Br J Pharmacol, 22, 463–477.
3. Macmillan AL (1973). Generalized pustular drug rash. Dermatologia, 146, 285–291.
4. McCullagh SF (1968). Allergenicity of piperazine: a study in environmental aetiology. Br J Ind Med, 25, 319–325.
5. Belloni C, Rizzoni G (1967). Neurotoxic side-effects of piperazine. Lancet, ii, 369.
6. Berger JR, Globus M, Melamed E (1979). Acute transitory cerebellar dysfunction associated with piperazine adipate. Arch Neurol, 36, 180–181.
7. Bomb RS, Bedi HK (1976). Neurotoxic side-effects of piperazine. Trans R Soc Trop Med Hyg, 70, 358.
8. Gupta SR (1976). Piperazine neurotoxicity and psychological reaction. J Ind Med Ass, 66, 33–34.
9. Parsons AC (1971). Piperazine neurotoxicity. ‘Worm wobble’. BMJ, 4, 790–792.
10. Vallat JN, Vallat JM, Texier J, Léger J (1972). Les signes neurologiques d’intoxication par la piperazine. Bordeaux Médicale, 5, 394–400.
11. Nickey LN (1966). Possible precipitation of petit mal seizures with piperazine citrate. J Am Med Ass, 195, 193–194.
12. Buchanan N, Cassel R, Jenkins T (1971). G-6-PD deficiency and piperazine. BMJ, 2, 110.
13. Hamlyn AN, Morris JS, Sarkany I, Sherlock S (1976). Piperazine hepatitis. Gastroenterology, 70, 1144–1147.
14. Bellander T, sterdahl B-G, Hagmar L (1985). Formation of N-mononitrosopiperazine in the stomach and its excretion in the urine after oral intake of piperazine. Toxicol Appl Pharmacol, 80, 193–198.
15. Sturman G (1973). Interaction between piperazine and chlorpromazine. Br J Pharmacol, 50, 153–155.

Flammability and hazardous characteristics

Combustible; decomposition of toxic nitric oxide gas in case of thermal

Storage characteristics

Treasury ventilation low-temperature drying; and stored separately from acid.
Since piperazine is corrosive, the flakes are stored in barrels lined with a polyethylene sack. To avoid yellowing, the barrels should be air tight and not exposed to direct sunlight. The aqueous solution is stored at 50 – 60 ℃ in insulated iron tanks that can be heated.

Extinguishing agent

Water spray, dry powder, carbon dioxide, alcohol-resistant foam

Professional standards

TWA 1 mg/m³; STEL 5 mg/m

Description

Piperazine is contained in pyrazinobutazone, an equimolecularsah of piperazine and phenylbutazone.Among occupational cases, most were reported in thepharmaceutical industry or laboratory, in nurses andin veterinarians.

Description

Piperazine (Item No. 24019) is an analytical reference standard categorized as a piperazine. This product is intended for research and forensic applications.

Chemical Properties

Colorless to yellow solid; salty taste.

Chemical Properties

Piperazine is white to cream-colored needles or powder. Characteristic ammonia-like odor. Combustible solids that do not easily ignite.

Uses

Labelled Piperazine

Uses

keratolytic, antiseborheic

Uses

Piperazine is used as an intermediate in themanufacture of dyes, pharmaceuticals, polymers,surfactants, and rubber accelerators.

Indications

Piperazine (Vermizine) contains a heterocyclic ring thatlacks a carboxyl group. It acts on the musculature of thehelminths to cause reversible flaccid paralysis mediatedby chloride-dependent hyperpolarization of the musclemembrane. This results in expulsion of the worm.Piperazine acts as an agonist at gated chloride channelson the parasite muscle.
Piperazine has been used with success to treat A.lumbricoides and E. vermicularis infections, althoughmebendazole is now the agent of choice. Piperazine isadministered orally and is readily absorbed from the intestinaltract. Most of the drug is excreted in the urinewithin 24 hours.
Piperazine is an appropriate alternative to mebendazolefor the treatment of ascariasis, especially in thepresence of intestinal or biliary obstruction. Cure ratesof more than 80% are obtained following a 2-day regimen.
Side effects occasionally include gastrointestinal distress,urticaria, and dizziness. Neurological symptoms ofataxia, hypotonia, visual disturbances, and exacerbations of epilepsy can occur in patients with preexistingrenal insufficiency. It should not be used in pregnantwomen because of the formation of a potentially carcinogenicand teratogenic nitrosamine metabolite.Concomitant use of piperazine and chlorpromazine orpyrantel should be avoided.

Definition

ChEBI: An azacycloalkane that consists of a six-membered ring containing two nitrogen atoms at opposite positions.

Brand name

Pincets (Marion Merrell Dow);Pinsirup (Marion Merrell Dow);Adelmintex;Adipalis;Adipalit;Adiver;Ancaris thenium;Ancazine;Antelmina;Antepar (b-w);Anterobius;Anthalazine;Anthelmina;Anticucs;Antivermine;Ascalix;Ascarinex;Ascarivet;Asca-trol no.3;Asepar;Askaripar;Averamexan;Bel-zine;Bioxurin;B-piperazine;Brirel;Candizine;Carudol;Ciperazin;Citrazine;Coopane;Dak;Demovermil;Diatesurico;Dicevermin;Digesan;Dilaurazine;Dispermin;Diurazina;Dowzene;Ecosan;Endorid;Entazin;Equizole-a;Escovermin;Esteropipate;Etaphylline (acetyllinate);Gentiazina;Glycopiparsol;Heksapar;Helmacid;Helmezin;Helmicide;Helmifren;Helmipar;Helmirazine (adipate);Helmirazine (citrate);Helmitin;Helmizin;Herb royal round worm treatment;Hexanthelin;Ismiverm;Janes liquid permifu;Jarabe neox;Jetsan supp. (adipate);Justalmin;Kennel-maid;Kihomato;Kontipar;Lamboxil;Lombricida tropico;Lombrifher;Lombrikal;Lombrimade;Mapiprin;Maskito;Noxiurotan;Ogen;Okuside;Optiverm;Oxiril syrup (hydrate);Oxiuran (hydrate);Oxiurasin;Oxiustip elix;Oxivermin;Oxizin;Oxucid;Oxuril;Oxypip;Oxyzin;P.c. (citrate);Padrax;Paravermin;Pariamate;Par-tega;Perin;Piavermit;Pincide;Pipan;Pip-a-ray;Pipenin;Piperacid;Piperamicin;Piperascat;Piperaskat;Piperate;Piperaverm;Piperazinal;Piperazine (adipate);Pipercrean;Piperex;Piperiod;Piperital od;Piperitol;Piper-jodina;Piperol fort;Piperone;Piperoverm;Pipertox;Piperver;Piperzinal;Pipeverm;Pipezol;Pipizan citrate;Pipracid;Piprazid;Piprazyl;Pipricide;Piptelate;Piverma;Polo-verm;Polyquil;Pripsen;Provtovermil;Razinol;Rondelim;Rondoxyl;Santoban;Siropar;Supraverm;Taenifigin;Teniver;Tivazine;Toxocan;Uricida;Uridina;Uroclear (hexamine);Urodan (phosphate);Urosolvina;Uvilon syrup (hydrate);Vanpar (hydrate);Veripar;Vermazine;Vermenter;Vermicompren;Vermidol;Vermifug;Vermilass;Vermipan;Vermiphsarmette;Vermiquimpe;Vermiquimyc;Vermisit;Vermitox;Vermofrik;Verocid;Wairmex;Wurmex;Wurmsirup siegfriedMultifuge;Multifuj;Nea-vermiol;Nemafugan;Nemasin;Nematocton;Nematorazine;Neo-ifusa;.

World Health Organization (WHO)

Piperazine was first used as a treatment for gout earlier thiscentury and its anthelminthic activity was discovered in 1949. It is alsoconsiderably cheaper than other anthelminthic drugs. In some countries whereascariasis is not endemic and where piperazine was used predominantly for thetreatment of pinworm it has been withdrawn from use on the grounds that othermore effective and less toxic drugs are now available (see full list). In other suchcountries, however, piperazine remains available in over-the-counter preparations.Clinical dosages occasionally induce transient neurological signs and concern hasbeen expressed that in some circumstances the drug may generate small amountsof nitrosamine in the stomach. However, it is widely considered that these tracedoses are unlikely to give rise to a significant carcinogenic potential.(Reference: (WHODIB) WHO Drug Information Bulletin, 1: 5, , 1983)

General Description

Needle-like white or colorless crystals. Shipped as a solid or suspended in a liquid medium. Very corrosive to skin, eyes and mucous membranes. Solid turns dark when exposed to light. Flash point 190°F. Used as a corrosion inhibitor and as an insecticide.

Air & Water Reactions

Flammable. Absorbs water and carbon dioxide from air. Soluble in water.

Reactivity Profile

1,4-Diazacyclohexane neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Absorbs carbon dioxide from the air, which can cause dry crystals to seem to melt. May generate hydrogen, a flammable gas, in combination with strong reducing agents such as hydrides. 1,4-Diazacyclohexane is sensitive to light; 1,4-Diazacyclohexane absorbs water and carbon dioxide from air. 1,4-Diazacyclohexane may be corrosive to aluminum, magnesium and zinc. .

Health Hazard

TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Health Hazard

Piperazine is a corrosive substance. The solidand its concentrated aqueous solutions areirritants to the skin and eyes. The irritanteffect in rabbits’ eyes was severe.
The toxic symptoms from ingestion ofpiperazine include nausea, vomiting, excitement,change in motor activity, somnolence,and muscle contraction. The toxicity of thiscompound is low, however. The oral LD50value in rats is 1900 mg/kg. The inhalationtoxicity is very low. The inhalation LC50value in mice is 5400 mg/m³/2 h.

Fire Hazard

Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.

Flammability and Explosibility

Highly flammable

Pharmaceutical Applications

A synthetic chemical, most commonly formulated as the citrate,but also available as the adipate, edetate calcium andtartrate salts.

Contact allergens

Piperazine is contained in pyrazinobutazone, an equimolarsalt of piperazine and phenylbutazone. Among occupationalcases, most were reported in the pharmaceuticalindustry or laboratory workers, in nurses, and inveterinarians.

Mechanism of action

Piperazine increases the resting potentialof the somatic musculature of nematodes, especiallyin the syncytial region, by increasing thepermeability of the membrane to chloride ions.This results in flaccid paralysis of the parasites,which are expelled from the intestine .

Pharmacokinetics

Activity against intestinal worms requires that a substantialamount remains in the gut. However, after oral administrationa variable amount is rapidly absorbed from the smallintestine and subsequently excreted in the urine. Its half-lifeis extremely variable.

Clinical Use

Hexahydropyrazine or diethylenediamine (Arthriticine,Dispermin) occurs as colorless, volatile crystals of the hexahydratethat are freely soluble in water. After the discoveryof the anthelmintic properties of a derivative diethylcarbamazine,the activity of piperazine itself was established.Piperazine is still used as an anthelmintic for the treatmentof pinworm (Enterobius [Oxyuris] vermicularis) and roundworm(Ascaris lumbricoides) infestations. It is available invarious salt forms, including the citrate (official in the USP)in syrup and tablet forms. Piperazine blocks the response of the ascaris muscleto acetylcholine, causing flaccid paralysis in the worm,which is dislodged from the intestinal wall and expelled inthe feces.

Clinical Use

Ascariasis
Pinworm

Side effects

Some people develop hypersensitivity, requiring cessation oftreatment. Transient, mild gastrointestinal or neurologicalsymptoms may occur.

Safety Profile

Moderately toxic byingestion, skin contact, intravenous, andsubcutaneous routes. Mildly toxic byinhalation. A skin and severe eye irritant.Excessive absorption can cause urticaria,vomiting, diarrhea, blurred vision, andweakness. Combustible when exposed toheat or flame; can react vigorously withoxidizing materials. Explodes on contactwith dicyanofurazan. To fight fire, usealcohol foam, mist, dry chemical, waterspray. When heated to decomposition itemits highly toxic fumes of NOx.

Synthesis

Piperazine (38.1.12) is a bulk product in organic synthesis. It is made fromethanolamine by heating it in ammonia at a temperature of 150¨C220??C and a pressure of 100¨C250atm. It is used as a drug in the form of a salt, and as a rule, in the form of adipinate.

Potential Exposure

(Piperazine): Primary irritant (w/o allergic reaction),

Veterinary Drugs and Treatments

Piperazine is used for the treatment of ascarids in dogs, cats, horses,swine and poultry. Piperazine is considered safe to use in animalswith concurrent gastroenteritis and during pregnancy.

Drug interactions

Potentially hazardous interactions with other drugs
Pyrantel: antagonises effect of piperazine.

Carcinogenicity

No increase in lung adenomaswas produced in mice administered 0.69–18.75mg of piperazine/kg in drinking water for 20–25 weeks and sacrificed10–13 weeks later. Mice fed the equivalent of938 mg/kg in the diet for 28 weeks and sacrificed at 40 weeksfailed to show any significant increase in the incidence oflung adenomas. An increase in lung adenomas wasproduced in this bioassay by administration of piperazinetogether with sodium nitrate, suggesting the formation of theactive nitroso derivative. Sodium ascorbate inhibitedtumor formation, in theory, by preventing piperazine nitrosation(304). Coadministration of 250 ppm piperazine and500 ppm sodium nitrate in drinking water did not producetumors in rats. None of these studies were conductedusing currently accepted methods for evaluating carcinogenicpotential but piperazine alone, in these assays, wasnoncarcinogenic.

Environmental Fate

This molecule has a simple chemical structure and molecularweight of 86.14. It has a strong alkaline base soluble in water(1:18), glycerol, and glycols, but is only sparingly soluble inalcohol and insoluble in ether. Piperazine is not expected tohydrolyze in water. The photodegradation half-life is approximately0.8 h. The piperazine molecule is easily denaturalizedby diverse environmental factors and has a low potential forbioaccumulation or biomagnification. To improve its stability,it is usually formulated as different salts such as adipate, citrate,phosphate, hexahydrate, and sulfate. Most piperazine salts arewhite crystalline powders that are readily soluble in water.Exceptions are adipates, which dissolve to only a maximumconcentration of 5% in water, and phosphate, which isinsoluble.

Metabolism

About 25% is metabolised in the liver. Piperazine is nitrosated to form N -mononitrosopiperazine (MNPz) in gastric juice, which is then metabolised to N-nitroso-3-hydroxypyrrolidine (NHPYR).
It is excreted in the urine mainly as metabolites.

Shipping

UN2579 Piperazine, Hazard class: 8; Labels: 8-Corrosive material.

Purification Methods

Piperazine crystallises from EtOH or anhydrous *benzene and is dried at 0.01mm. It can be sublimed under vacuum and purified by zone melting. The hydrochloride has m 172-174o (from EtOH), and the dihydrochloride crystallises from aqueous EtOH and has m 318-320o (dec, sublimes at 295-315o). The picrate has m ~200o, and the picrolonate crystallises from dimethylformamide ( m 259-261o). [Beilstein 23 H 4, 23 I 4, 23 II 3, 23 III/IV 15, 23/1 V 30.]

Toxicity evaluation

Piperazine blocks transmission by hyperpolarizing nervemembranes at the neuromuscular junction, leading to parasiteimmobilization by flaccid paralysis and consequent removalfrom predilection and death. Piperazine is a selective agonist ofGABA receptors, resulting in the opening of chloride channelsand hyperpolarization of the membrane of the muscle cells ofnematode parasites.

Incompatibilities

Aqueous solution is a strong base. Violent reaction with strong oxidizers and dicyanofurazan. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides, nitrogen compounds, carbon tetrachloride. Attacks aluminum, copper, nickel, magnesium and zinc.

Piperazine Preparation Products And Raw materials

• Raw materials: Ammonium hydroxide-->Monoethanolamine-->2-Chloroethanol-->Paraffin wax-->PIPERAZINE HEXAHYDRATE-->PIPERAZINE DIHYDROCHLORIDE-->ETHANOLAMINE HYDROCHLORIDE
• Preparation Products: 1-(3-METHOXYPROPYL)-PIPERAZINE-->1-(3-PHENYLPROPYL)PIPERAZINE-->1-Boc-piperazine acetate-->Sarafloxacin-->TRIFORINE-->1-[5-(Trifluoromethyl)pyridin-2-yl]piperazine-->Terazosin-->Ziprasidone hydrochloride monohydrate-->4-Amino-3-hydrazino-1,2,4-triazol-5-thiol-->2-PIPERAZIN-1-YLISONICOTINIC ACID-->1-[3-(DIMETHYLAMINO)PROPYL]PIPERAZINE-->1,4-Bis(3-aminopropyl)piperazine-->2-PIPERAZIN-1-YL-ACETAMIDEHYDROCHLORIDE-->clopenthixol-->Flunarizine dihydrochloride-->1-(CYCLOHEXYLCARBONYL)PIPERAZINE-->1-BOC-PIPERAZINE-->1-(2-CHLORO-6-FLUOROBENZYL)PIPERAZINE-->4-Piperazinobenzonitrile-->1-Butylpiperazine-->1-(4-PYRIDYLMETHYL)PIPERAZINE-->Amoxapine-->1-(1-Methyl-4-piperidinyl)piperazine-->1-(3-Nitorpyridin-2-yl)piperazine-->Cefbuperazone-->VESNARINONE-->BENZYL 1-PIPERAZINECARBOXYLATE-->1-(3-CHLOROBENZYL)PIPERAZINE-->1-(2-CHLOROBENZYL)PIPERAZINE-->TRANS-1-CINNAMYLPIPERAZINE-->3-PIPERAZIN-1-YL-PROPIONITRILE-->N,N-DIMETHYL-2-PIPERAZIN-1-YL-ACETAMIDE-->1-[3-(TRIFLUOROMETHYL)PYRID-2-YL]PIPERAZINE-->1,4-DIFORMYLPIPERAZINE-->PIPERAZINE-1-CARBOXYLIC ACID DIMETHYLAMIDE-->1-(3-METHYLPYRIDIN-2-YL)PIPERAZINE-->Piperazine citrate-->4-(3-CHLOROPROPYL)-1-PIPERAZINE ETHANOL-->1-[2-(4-PYRIDYL)ETHYL]PIPERAZINE-->Piperaquinoline