4-Fluoro-1H-pyrazole Chemical Properties

Melting point:

38-40 °C

Boiling point:

193℃

Density 

1.320

Flash point:

70℃

storage temp. 

Keep in dark place,Sealed in dry,Room Temperature

pka

13.66±0.50(Predicted)

form 

low melting solid

color 

Colourless to off-white

InChI

InChI=1S/C3H3FN2/c4-3-1-5-6-2-3/h1-2H,(H,5,6)

InChIKey

RYXJXPHWRBWEEB-UHFFFAOYSA-N

SMILES

N1C=C(F)C=N1

Safety Information

WGK Germany 

WGK 3

HS Code 

2933199090

Storage Class

11 - Combustible Solids

Hazard Classifications

Acute Tox. 4 Oral
Eye Dam. 1
Skin Irrit. 2
STOT SE 3

4-Fluoro-1H-pyrazole Usage And Synthesis

Uses

4-Fluoropyrazole is used in preparation and palladium catalyzed cross-coupling reactions of tributylstannyl fluoropyrazole.

Synthesis

General procedure for the synthesis of 4-fluoro-1H-pyrazole using the compound (CAS: 761-88-6) as starting material: dihydrazine (4.48 g, 0.043 mol) was added to (Z)-3-(dimethylamino)-2-fluoroacrylaldehyde (5 g, 0.043 mol) in 100 mL of 40% (V/V) aqueous ethanol solution. Subsequently, the reaction mixture was heated at 55 °C for 30 min. After completion of the reaction, the mixture was cooled to room temperature and the pH was adjusted with saturated aqueous sodium bicarbonate to 9. The aqueous layer was extracted with ether and the organic layers were combined and dried with anhydrous sodium sulfate. Finally, the solvent was removed by distillation under reduced pressure to give 3.6 g of the title compound 28-d as a yellow oil in 77% yield.

References

[1] Patent: WO2013/40790, 2013, A1. Location in patent: Page/Page column 87; 88
[2] Patent: WO2013/43624, 2013, A1. Location in patent: Page/Page column 87; 88

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