1-Boc-4-bromopyrazole Chemical Properties

Melting point:

48-52 °C

Boiling point:

288.7±32.0 °C(Predicted)

Density 

1.47±0.1 g/cm3(Predicted)

storage temp. 

Keep in dark place,Sealed in dry,Room Temperature

form 

solid

pka

-3.17±0.12(Predicted)

Appearance

Off-white to light yellow Solid

InChI

InChI=1S/C8H11BrN2O2/c1-8(2,3)13-7(12)11-5-6(9)4-10-11/h4-5H,1-3H3

InChIKey

IQEFCRDQVLIADR-UHFFFAOYSA-N

SMILES

N1(C(OC(C)(C)C)=O)C=C(Br)C=N1

Safety Information

Hazard Codes 

Xn

Risk Statements 

22

WGK Germany 

3

HS Code 

2933199090

1-Boc-4-bromopyrazole Usage And Synthesis

Synthesis

Step 1: Preparation of tert-butyl 4-bromo-1H-pyrazole-1-carboxylate Di-tert-butyl dicarbonate (Boc2O, 2.34 mL, 10.2 mmol) was slowly added to a solution of 4-bromo-1H-pyrazole (1 g, 6.8 mmol) in acetonitrile (20 mL) at 0 °C. Subsequently, triethylamine (3.3 mL, 23.8 mmol) and 4-dimethylaminopyridine (DMAP, 0.166 g, 1.36 mmol) were added sequentially to the reaction mixture. The reaction mixture was stirred at room temperature for 2 hours. After completion of the reaction, the reaction mixture was diluted with water and extracted with ethyl acetate (100 mL × 3). The organic phases were combined, washed sequentially with water (100 mL) and saturated saline (100 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent. The crude product was purified by fast column chromatography (eluent: 10% ethyl acetate/hexane) to afford tert-butyl 4-bromo-1H-pyrazole-1-carboxylate (1.65 g, 98% yield) as a colorless liquid. 1H NMR (400 MHz, CDCl3) δ 8.09 (s, 1H), 7.66 (s, 1H), 1.65 (s, 9H).

References

[1] Patent: WO2016/49165, 2016, A1. Location in patent: Paragraph 00161
[2] Patent: WO2018/172250, 2018, A1. Location in patent: Page/Page column 300
[3] Patent: CN106188116, 2016, A. Location in patent: Paragraph 0016
[4] Patent: WO2014/141187, 2014, A1. Location in patent: Page/Page column 142
[5] Arkivoc, 2014, vol. 2014, # 6, p. 54 - 71

1-Boc-4-bromopyrazole(1150271-23-0)Related Product Information

• tert-Butyl 1H-pyrazole-1-carboxylate
• 6-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)quinoxaline
• t-Butyl 4-bromo-1-naphthalenecarboxylate
• 4-Bromopyrazole