1-METHYL-3-TRIFLUOROMETHYLPYRAZOLE-5-BORONIC ACID Chemical Properties

Melting point:

132-137°C

Boiling point:

311.3±52.0 °C(Predicted)

Density 

1.46±0.1 g/cm3(Predicted)

storage temp. 

2-8°C

form 

powder or crystals

pka

6.97±0.58(Predicted)

Appearance

White to off-white Solid

InChI

InChI=1S/C5H6BF3N2O2/c1-11-4(6(12)13)2-3(10-11)5(7,8)9/h2,12-13H,1H3

InChIKey

XPUNXPPXMANQGF-UHFFFAOYSA-N

SMILES

B(C1N(C)N=C(C(F)(F)F)C=1)(O)O

Safety Information

WGK Germany 

3

HS Code 

2933199090

Storage Class

11 - Combustible Solids

1-METHYL-3-TRIFLUOROMETHYLPYRAZOLE-5-BORONIC ACID Usage And Synthesis

Synthesis

The general procedure for the synthesis of (1-methyl-3-trifluoromethyl-1H-pyrazol-5-yl)boronic acid from 1-methyl-3-trifluoromethyl-1H-pyrazole was as follows: 1-methyl-3-trifluoromethyl-1H-pyrazole (1.00 g, 6.66 mmol) was dissolved in THF (25 mL) in an oven-dried, round-bottomed flask. The flask was cooled to -78°C in an acetone/dry ice bath. Under stirring, 2.5 M n-butyllithium/hexane solution (3.196 ml, 7.99 mmol) was slowly added dropwise to the solution, followed by triisopropyl borate (5.01 g, 26.64 mmol). The reaction mixture was gradually warmed to room temperature and stirred continuously for 3 hours. Upon completion of the reaction, the pH of the reaction mixture was adjusted to 6 with 1N HCl solution, followed by removal of THF under vacuum.The aqueous phase was extracted with EtOAc (3 x 100 ml). The organic phases were combined, washed with brine and dried with anhydrous MgSO4. After filtration, the solvent was evaporated to give 2-methyl-5-trifluoromethyl-2H-pyrazole-3-boronic acid (1.12 g, 5.80 mmol, 87% yield) as a white solid. The product was analyzed by LCMS, m/z (%) = 195 (M+H, 100). 1H NMR (400 MHz, DMSO-d6) δ: 8.37-8.40 (m, 2H), 7.57 (dd, J=4.0 Hz, 1H), 4.06 (s, 3H).

References

[1] Patent: WO2005/12254, 2005, A1. Location in patent: Page/Page column 135-136

1-METHYL-3-TRIFLUOROMETHYLPYRAZOLE-5-BORONIC ACID(344591-91-9)Related Product Information

• (1-Methyl-1H-pyrazol-5-yl)-boronic acid
• Pyrazole-3-boronic acid
• 1-METHYL-3-TRIFLUOROMETHYLPYRAZOLE-5-BORONIC ACID