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

Melting point:

91-93°C

Boiling point:

335.7±42.0 °C(Predicted)

Density 

1.04±0.1 g/cm3(Predicted)

storage temp. 

Inert atmosphere,Store in freezer, under -20°C

solubility 

soluble in Methanol

form 

powder to crystal

pka

3.13±0.10(Predicted)

color 

White to Almost white

InChIKey

IZNGYNMIIVJWSO-UHFFFAOYSA-N

CAS DataBase Reference

844891-04-9

Safety Information

Hazard Codes 

Xi,Xn

Risk Statements 

36/37/38-22

Safety Statements 

26-36/37/39-36-22

WGK Germany 

3

Hazard Note 

Harmful

HS Code 

2933199090

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

Synthesis

General procedure for the synthesis of 1,3,5-trimethyl-1H-pyrazole-4-boronic acid pinacol ester from 3,5-dimethylpyrazole-4-boronic acid pinacol ester and iodomethane: 3,5-dimethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (500 mg, 2.25 mmol) was suspended in acetone (5 mL) in acetone (5 mL), potassium carbonate (622 mg, 4.5 mmol) and iodomethane (0.21 mL, 3.37 mmol) were added. The reaction mixture was heated to 60 °C and kept for 4.5 hours. After completion of the reaction, it was cooled to room temperature, water was added, the aqueous phase was separated and extracted three times with ethyl acetate (EtOAc). The organic phases were combined, washed with water, dried over anhydrous magnesium sulfate (MgSO4), and concentrated in vacuo to afford 1,3,5-trimethyl-1H-pyrazole-4-boronic acid pinacol ester (403 mg, 76%) as a light yellow oil.LCMS (ES+) m/z 237 (M+H)+, retention time (RT) 3.35 min (Method 1).

References

[1] Patent: WO2009/71895, 2009, A1. Location in patent: Page/Page column 117
[2] Patent: US2016/176882, 2016, A1. Location in patent: Paragraph 0366; 0367
[3] Patent: WO2017/221100, 2017, A1. Location in patent: Paragraph 00174
[4] Patent: WO2013/96153, 2013, A1. Location in patent: Page/Page column 173-174

1,3,5-TRIMETHYL-4-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)-1H-PYRAZOLE(844891-04-9)Related Product Information

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• 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
• 1-(2,2-DIMETHOXY-ETHYL)-3,5-DIMETHYL-4-(4,4,5,5-TETRAMETHYL-[1,3,2]DIOXABOROLAN-2-YL)-1H-PYRAZOLE