(1-Methyl-1H-pyrazol-5-yl)-boronic acid Chemical Properties

Boiling point:

323.0±34.0 °C(Predicted)

Density 

1.23±0.1 g/cm3(Predicted)

storage temp. 

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

pka

8.00±0.58(Predicted)

Appearance

White to off-white Solid

InChI

InChI=1S/C4H7BN2O2/c1-7-4(5(8)9)2-3-6-7/h2-3,8-9H,1H3

InChIKey

MGNBKNBEZGLHNF-UHFFFAOYSA-N

SMILES

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

Safety Information

Risk Statements 

36

Safety Statements 

26

HS Code 

2933199090

(1-Methyl-1H-pyrazol-5-yl)-boronic acid Usage And Synthesis

Uses

1-Methyl-1H-pyrazole-5-boronic Acid acts as a reagent for the design, synthesis and evaluation of novel porcupine inhibitors featuring a fused 3-ring system based on ‘reversed’ amide scaffold.

Synthesis

General procedure for the synthesis of 1-methyl-1H-pyrazole-5-boronic acid from 1-methylpyrazole: 1-methylpyrazole (25 mL, 0.3 mol) was dissolved in 500 mL of tetrahydrofuran (THF). The solution was then cooled to -78°C in a dry ice/isopropanol bath. After the solution temperature stabilized at -78 °C, n-butyllithium (n-BuLi, 140 mL, 0.40 mol) was slowly added dropwise through the cannula. After the dropwise addition, the reaction mixture was stirred continuously at -78 °C for 1.5 hours. Next, triisopropyl borate (280 mL, 1.2 mol) was added to the reaction system via cannula and the reaction mixture was allowed to slowly warm from -78 °C to 0 °C while stirring overnight. Upon completion of the reaction, the pH of the mixture was adjusted to 6 with 1 N hydrochloric acid (HCl).Subsequently, THF was evaporated under reduced pressure and the remaining aqueous phase was extracted with ethyl acetate (EtOAc, 2 × 100 mL). Finally, the solid was collected by filtration to afford 108 g (100% yield) of 1-methyl-1H-pyrazole-5-boronic acid as a yellow solid.

References

[1] Patent: WO2005/12254, 2005, A1. Location in patent: Page/Page column 101
[2] Journal of Medicinal Chemistry, 2010, vol. 53, # 5, p. 1923 - 1936
[3] Journal of Heterocyclic Chemistry, 2004, vol. 41, # 6, p. 931 - 939
[4] Patent: WO2004/58722, 2004, A1. Location in patent: Page 63; 62

(1-Methyl-1H-pyrazol-5-yl)-boronic acid(720702-41-0)Related Product Information

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• 5-(5,5-DIMETHYL-1,3,2-DIOXABORINAN-2-YL)-1-METHYL-1H-PYRAZOLE
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