4-Chloropyrazole Chemical Properties

Melting point:

75-76 ºC

Boiling point:

220 ºC

Density 

1.405

Flash point:

99 ºC

storage temp. 

Keep in dark place,Sealed in dry,Room Temperature

form 

powder to crystal

pka

12.71±0.50(Predicted)

color 

White to Almost white

λmax

224nm(lit.)

InChI

InChI=1S/C3H3ClN2/c4-3-1-5-6-2-3/h1-2H,(H,5,6)

InChIKey

BADSZRMNXWLUKO-UHFFFAOYSA-N

SMILES

N1C=C(Cl)C=N1

CAS DataBase Reference

15878-00-9(CAS DataBase Reference)

Safety Information

Hazard Codes 

Xi,Xn

Risk Statements 

36/37/38-22

Safety Statements 

26-36/37/39

RTECS 

UQ6445000

HazardClass 

IRRITANT

HS Code 

2933199090

4-Chloropyrazole Usage And Synthesis

Chemical Properties

White to light yellow crystalline powder

Synthesis

General method: synthesis of 1-benzyl-4-chloro-3,5-dimethyl-1H-pyrazole. To a 16 mL reaction vial containing 1-benzyl-3,5-dimethyl-1H-pyrazole (196 mg, 1.05 mmol) and a magnetic stirrer, 0.7 mL of water and 0.3 mL of ethyl acetate were added sequentially. Subsequently, sodium chloride (123 mg, 2 mmol) was added and the reaction flask was placed in a room temperature water bath to control the exothermic nature of the reaction. Next, Oxone (322 mg, 0.52 mmol KHSO5) was added and the reaction vial was sealed. The reaction was carried out under continuous vigorous stirring until thin layer chromatography (TLC) analysis (1 h) showed complete consumption of the feedstock. The remaining oxidant was reduced by addition of solid sodium bisulfite until starch iodide paper tested negative. The reaction mixture was diluted with water (5 mL) and extracted with a 1:1 hexane/ether solvent mixture (3 x 5 mL). The organic phases were combined, dried with anhydrous magnesium sulfate and concentrated under reduced pressure to give the crude product. The crude product was purified by fast column chromatography (14×1 cm, eluent 9:1 hexane/ethyl acetate) to afford pure 1-benzyl-4-chloro-3,5-dimethyl-1H-pyrazole as a light yellow oil (215 mg, 93% yield).

References

[1] Canadian Journal of Chemistry, 1991, vol. 69, # 3, p. 432 - 439
[2] Journal of Heterocyclic Chemistry, 2014, vol. 51, # 6, p. 1621 - 1627
[3] Tetrahedron Letters, 2017, vol. 58, # 43, p. 4111 - 4114
[4] Advanced Synthesis and Catalysis, 2013, vol. 355, # 2-3, p. 499 - 507
[5] Angewandte Chemie - International Edition, 2016, vol. 55, # 52, p. 16132 - 16135

4-Chloropyrazole(15878-00-9)Related Product Information

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• 4-CHLORO-1-METHYL-1H-PYRAZOLE-3-CARBALDEHYDE
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• 3-trifluoromethyl-1-methyl-1H-5-chloroPyrazole
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• 5,7-DICHLOROPYRAZOLO[1,5-A]PYRIMIDINE
• 1-(4-Chlorophenyl)-3-methyl-2-pyrazolin-5-one
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• 3-trifluoromethyl-1-methyl-1H-5-chloropyrazole-4-carbaldehyde
• 4-CHLORO-3-FORMYLPYRAZOLE
• 4-CHLORO-1-METHYL-1H-PYRAZOLE-3-CARBONITRILE
• (4-CHLORO-PYRAZOL-1-YL)-ACETIC ACID