| Identification | More | [Name]
Pyrazole | [CAS]
288-13-1 | [Synonyms]
1,2-DIAZOL
1,2-DIAZOLE
1H-PYRAZOLE
PYRAZOL
PYRAZOLE
1H-Pyrazol
Pyrazole(Rri124)~99%
Pyrrazole
Pyrazole, pure, 98%
Pyrazole ,99%
PYRAZOLE, 98%, PURE | [EINECS(EC#)]
206-017-1 | [Molecular Formula]
C3H4N2 | [MDL Number]
MFCD00005234 | [Molecular Weight]
68.08 | [MOL File]
288-13-1.mol |
| Chemical Properties | Back Directory | [Appearance]
white to yellow crystals or crystalline powder | [Melting point ]
67-70 °C (lit.) | [Boiling point ]
186-188 °C (lit.) | [density ]
1.4088 (rough estimate) | [vapor pressure ]
21Pa at 20℃ | [refractive index ]
1.4203 | [Fp ]
186-188°C | [storage temp. ]
Store below +30°C. | [solubility ]
Chloroform, Methanol | [form ]
Crystals or Crystalline Powder | [pka]
2.49(at 25℃) | [color ]
White to yellow | [Water Solubility ]
SOLUBLE | [Specific Heat Capacity]
Cp(crystal):1.18978J/(g·K),at 25℃ | [Sensitive ]
Hygroscopic | [Detection Methods]
GC | [Merck ]
14,7960 | [BRN ]
103775 | [InChI]
1S/C3H4N2/c1-2-4-5-3-1/h1-3H,(H,4,5) | [InChIKey]
WTKZEGDFNFYCGP-UHFFFAOYSA-N | [SMILES]
c1cn[nH]c1 | [LogP]
0.33 at 25℃ | [CAS DataBase Reference]
288-13-1(CAS DataBase Reference) | [NIST Chemistry Reference]
1H-Pyrazole(288-13-1) | [EPA Substance Registry System]
288-13-1(EPA Substance) |
| Safety Data | Back Directory | [Symbol(GHS) ]
  
GHS05,GHS06,GHS08 | [Signal word ]
Danger | [Hazard statements ]
H302-H311-H315-H318-H373-H412 | [Precautionary statements ]
P273-P280-P301+P312-P302+P352+P312-P305+P351+P338-P314 | [Hazard Codes ]
Xn | [Risk Statements ]
R22:Harmful if swallowed.
R36/37/38:Irritating to eyes, respiratory system and skin .
R52:Harmful to aquatic organisms.
R20/21/22:Harmful by inhalation, in contact with skin and if swallowed . | [Safety Statements ]
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S36/37:Wear suitable protective clothing and gloves .
S61:Avoid release to the environment. Refer to special instructions safety data sheet .
S37/39:Wear suitable gloves and eye/face protection .
S36:Wear suitable protective clothing . | [RIDADR ]
2811 | [WGK Germany ]
1
| [RTECS ]
UQ4900000
| [TSCA ]
Yes | [REACH Registrations]
Active | [HazardClass ]
6.1(b) | [PackingGroup ]
III | [HS Code ]
29331990 | [Storage Class]
6.1C - Combustible acute toxic Cat.3
toxic compounds or compounds which causing chronic effects | [Hazard Classifications]
Acute Tox. 3 Dermal
Acute Tox. 4 Oral
Aquatic Chronic 3
Eye Dam. 1
Skin Irrit. 2
STOT RE 1 | [Safety Profile]
Moderately toxic by ingestion and intraperitoneal routes. Experimental teratogenic and reproductive effects. When heated to decomposition it emits toxic fumes of NOx. | [Toxicity]
LD50 (24 hr) in rats, mice (mmol/kg): 19, 21 i.v.; 21, 22 orally (Magnussen) |
| Hazard Information | Back Directory | [Hazard]
Toxic by ingestion and inhalation, irritant
to skin and eyes.
| [Chemical Properties]
white to yellow crystals or crystalline powder | [Uses]
Chelating agent; in organic synthesis. | [Uses]
Pyrazole is used in organic synthesis and asa chelating agent. | [Uses]
Used as a ligand to prepare organometallic compounds.1,2 | [Definition]
A heterocyclic crystalline aromatic compound with a five-membered
ring containing three carbon atoms and
two nitrogen atoms. | [Definition]
ChEBI: The 1H-tautomer of pyrazole. | [Definition]
pyrazole: An unsaturated heterocycliccompound having two nitrogenatoms in a five-membered ring,C3H4N2; m.p. 66–70°C; b.p. 168–188°C. Pyrazine is a symmetricdiazine. | [General Description]
Pyrazine is a heterocyclic crystalline aromatic compound with a five-membered ring containing three carbon atoms and two nitrogen atoms. It is a symmetricdiazine. | [Health Hazard]
The acute toxic symptoms from oral administrationof pyrazole in experimental animalswere ataxia, muscle weakness, and respiratorydepression. It is less toxic than pyrroleand pyrrolidine. The oral LD50 value in miceis within the range 1450 mg/kg.
Pyrazole exhibited reproductive toxicityin rats and mice when administered by oralor intraperitoneal route. The effects includefetal death, developmental abnormalities pertainingto the urogenital system, and postimplantationmortality. | [Fire Hazard]
Noncombustible solid. | [Flammability and Explosibility]
Notclassified | [Synthesis]
Pyrazoles are synthesized via the condensation of hydrazines with 1,3-dicarbonyl compounds or their synthetic equivalents, as well as through 1,3-dipolar cycloaddition reactions of diazo compounds with dipolarophiles. They can also be produced by the in situ generation of nitrile imines from aromatic hydrazines and aldehydes through Oxone-KBr oxidation and base-promoted dehydrobromination, followed by cycloaddition with alkene or alkyne groups[1][2].
 | [Purification Methods]
Crystallise pyrazole from pet ether, cyclohexane, or water. Its solubility in H2O at 9.6o is 2.7moles/L, and at 24.8o it is 19.4moles/L; in cyclohexane at 31.8o it is 0.577moles/L, and at 56.2o it is 5.86moles/L; and in benzene at 5.2o it is 0.31moles/L, and at 46.5o it is 16.8moles/1000mL. [Barszcz et al. J Chem Soc, Dalton Trans 2025 1986, Beilstein 23 H 39, 23 I 15, 23 II 33, 23 III/IV 550, 23/4 V 122.] | [References]
[1]Chandrasekharan, S. P., Dhami, A., Kumar, S., & Mohanan, K. (2022). Recent advances in pyrazole synthesis employing diazo compounds and synthetic analogues. Organic & Biomolecular Chemistry, 20(45), 8787–8817. https://doi.org/10.1039/d2ob01918c
[2]Zhou, J., Zhou, Q., & Wan, J.-P. (2024). Recent advances in the multicomponent synthesis of pyrazoles. Organic & Biomolecular Chemistry, 22(40), 8065–8077. https://doi.org/10.1039/d4ob01211a |
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| Company Name: |
J & K SCIENTIFIC LTD.
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| Telephone: |
18210857532 18210857532 |
| Website: |
https://www.jkchemical.com |
| Company Name: |
Alfa Aesar
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| Telephone: |
400-6106006 |
| Website: |
http://chemicals.thermofisher.cn |
| Company Name: |
Energy Chemical
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| Telephone: |
400-0056266 |
| Website: |
www.energy-chemical.com |
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