| Identification | Back Directory | [Name]
1-Boc-4-bromopyrazole | [CAS]
1150271-23-0 | [Synonyms]
1-Boc-4-bromopyrazole
N-Boc-4-broMopyrazole
tert-butyl 4-bromopyrazole-1-carboxylate
t-Butyl 4-bromo-1H-pyrazole-1-carboxylate
1H-Pyrazole-1-carboxylic acid, 4-bromo-, 1,1-dimethylethyl ester | [Molecular Formula]
C8H11BrN2O2 | [MDL Number]
MFCD09999163 | [MOL File]
1150271-23-0.mol | [Molecular Weight]
247.09 |
| Chemical Properties | Back Directory | [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 |
| Hazard Information | Back Directory | [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 |
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