1-ISOBUTYL-4-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)-1H-PYRAZOLE Chemical Properties

Boiling point:

248-249 °C(lit.)

Density 

1.003 g/mL at 25 °C(lit.)

refractive index 

n20/D 1.4740(lit.)

Flash point:

118 °F

storage temp. 

2-8°C

pka

2.07±0.10(Predicted)

form 

Liquid

color 

Colorless to yellow

CAS DataBase Reference

827614-66-4

Safety Information

Hazard Codes 

Xi

Risk Statements 

10-36/38

Safety Statements 

16-26-36

RIDADR 

UN 1993 3/PG 3

WGK Germany 

3

HazardClass 

3

HS Code 

2933199090

MSDS

• Language:English Provider:SigmaAldrich

1-ISOBUTYL-4-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)-1H-PYRAZOLE Usage And Synthesis

Uses

1-Isobutylpyrazole-4-boronic acid, pinacol ester

Uses

1-Isobutylpyrazole-4-boronic acid pinacol ester can be used:

• In the synthesis of 7-azaindole derivatives as potent PDK1 inhibitors.
• As a reactant in the synthesis of imidazo[1,2-a]pyrazine derivatives as potent phosphodiesterase 10A inhibitors.
• To prepare 2-substituted-3-aroyl-benzo[b]furan derivatives.

Synthesis

To 4-pyrazoleboronic acid pinacol ester (1 g, 5.15 mmol, 1.00 eq.) and isobutyl bromide (1.05 g, 7.66 mmol, 1.49 eq.) in ethyl acetate (60 mL), Cs2CO3 (3.36 g, 10.31 mmol, 2.00 eq.) was added. The reaction mixture was stirred at 80 °C for 4 hours. After completion of the reaction, it was cooled to room temperature and filtered to remove insoluble solids. The filtrate was diluted with ethyl acetate (30 mL) and subsequently washed with brine (40 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated in vacuum to afford 1-isobutyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.14 g, 88% yield) as a colorless oil.1H-NMR (300 MHz, CDCl3): δ 7.78 (s, 1H), 7.65 (s, 1H), and 3.91 (d, J=7.2Hz, 2H), 2.24-2.19 (m, 1H), 1.32 (s, 12H), 0.90 (d, J=7.2Hz, 6H) ppm. lcms (method D, ESI): rt=1.51min, m/z=251.0[M+H]+.

References

[1] Patent: US2014/288105, 2014, A1. Location in patent: Paragraph 0216-0217
[2] Patent: EP3042907, 2016, A1. Location in patent: Paragraph 0277; 0278
[3] Journal of Medicinal Chemistry, 2009, vol. 52, # 24, p. 7934 - 7937

1-ISOBUTYL-4-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)-1H-PYRAZOLE(827614-66-4)Related Product Information

• Boron
• 1-Methyl-1H-pyrazole-4-boronic acid
• 1-Methyl-4-pyrazole boronic acid pinacol ester
• 1-Propyl-1H-pyrazole-4-boronic acid pinacol ester
• 1H-PYRAZOLE-4-BORONIC ACID
• 1-ISOBUTYL-4-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)-1H-PYRAZOLE
• 4-Pyrazoleboronic acid pinacol ester
• 1-Ethyl-1H-pyrazole-4-boronic acid, pinacol ester
• 1-Isobutyl-1H-pyrazole-4-boronic acid