3-Methyl-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole Chemical Properties

Melting point:

129-134℃

Boiling point:

350.3±30.0 °C(Predicted)

Density 

1.07±0.1 g/cm3(Predicted)

storage temp. 

under inert gas (nitrogen or Argon) at 2-8°C

form 

solid

pka

13.92±0.50(Predicted)

color 

White

InChI

InChI=1S/C10H17BN2O2/c1-7-8(6-12-13-7)11-14-9(2,3)10(4,5)15-11/h6H,1-5H3,(H,12,13)

InChIKey

MSJAEFFWTBMIKT-UHFFFAOYSA-N

SMILES

N1C=C(B2OC(C)(C)C(C)(C)O2)C(C)=N1

CAS DataBase Reference

936250-20-3

Safety Information

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26

WGK Germany 

3

HS Code 

29349990

3-Methyl-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole Usage And Synthesis

Chemical Properties

Solid

Uses

suzuki reaction

Synthesis

The general procedure for the synthesis of 3-methylpyrazole-4-boronic acid pinacol ester from 4-bromo-3-methyl-1H-pyrazole-1-carboxylic acid tert-butyl ester and pinacol ester of bis-boronic acid is as follows: 1. tert-butyl 4-bromo-3-methyl-1H-pyrazole-1-carboxylate (0.48 g, 1.84 mmol), bis(pinacolato)diboron (0.535 g, 2.1 mmol), dichloro[1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloromethane adduct (0.156 g, 0.19 mmol), and potassium acetate ( 0.56 g, 5.7 mmol) were added sequentially to a sealed tube. 2. Add DMSO (5 mL) as a solvent to ensure that all solids are fully dissolved. 3. Flush the reaction system with nitrogen to remove oxygen and subsequently seal the reaction tube. 4. Heat the reaction mixture to 90°C and maintain this temperature for 18 hours. 5. 5. Upon completion of the reaction, the solvent was removed and the crude product was purified by silica gel column chromatography (eluent: 50% ethyl acetate in hexane solution) to afford the target compound, 3-methylpyrazole-4-boronic acid pinacol ester (0.2 g, 50% yield). 6. The structure of the product was confirmed by mass spectrometry (ESI), m/z 209.1 [M + 1]+.

References

[1] Patent: WO2008/51493, 2008, A2. Location in patent: Page/Page column 181
[2] Patent: US2013/123281, 2013, A1. Location in patent: Paragraph 0127

3-Methyl-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole(936250-20-3)Related Product Information

• Boric acid
• 1-(2,2-DIMETHOXY-ETHYL)-3,5-DIMETHYL-4-(4,4,5,5-TETRAMETHYL-[1,3,2]DIOXABOROLAN-2-YL)-1H-PYRAZOLE
• 5-METHYL-1-PHENYL-4-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)-1H-PYRAZOLE
• 1,5-Dimethyl-1H-pyrazole-4-boronic acid,pinacol ester
• 1,3-Dimethyl-1H-pyrazole-4-boronic acid,pinacol ester
• 1-TERT-BUTOXYCARBONYL-3,5-DIMETHYLPYRAZOLE-4-BORONIC ACID, PINACOL ESTER
• 1,3,5-TRIMETHYL-4-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)-1H-PYRAZOLE
• 5-AMINO-3-METHYLPYRAZOLE-4-BORONIC ACID PINACOL ESTER
• 3-Methyl-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole