4-bromo-1-tert-butyl-1H-pyrazole manufacturers
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| | 4-bromo-1-tert-butyl-1H-pyrazole Basic information |
| Product Name: | 4-bromo-1-tert-butyl-1H-pyrazole | | Synonyms: | 4-bromo-1-tert-butyl-1H-pyrazole;4-Bromo-1-t-butylpyrazole;1-tert-Butyl-4-Bromopyrazole;4-Bromo-1-tert-butylpyrazole;4-bromo-1-t-butyl-1H-pyrazole;1H-Pyrazole, 4-bromo-1-(1,1-dimethylethyl)- | | CAS: | 70951-85-8 | | MF: | C7H11BrN2 | | MW: | 203.08 | | EINECS: | | | Product Categories: | | | Mol File: | 70951-85-8.mol |  |
| | 4-bromo-1-tert-butyl-1H-pyrazole Chemical Properties |
| Boiling point | 229.8±13.0℃ (760 Torr) | | density | 1.37±0.1 g/cm3 (20 ºC 760 Torr) | | Fp | 92.8±19.8℃ | | storage temp. | 2-8°C | | Appearance | Colorless to light yellow Liquid | | InChI | InChI=1S/C7H11BrN2/c1-7(2,3)10-5-6(8)4-9-10/h4-5H,1-3H3 | | InChIKey | KLLXOOSSATXFFY-UHFFFAOYSA-N | | SMILES | N1(C(C)(C)C)C=C(Br)C=N1 |
| | 4-bromo-1-tert-butyl-1H-pyrazole Usage And Synthesis |
| Synthesis | 1. N-bromosuccinimide (NBS, 2.63 kg, 14.79 mol) was added batchwise to a solution of 1-tert-butylpyrazole (1.75 kg, 14.09 mol) in dichloromethane (12.9 kg) in an ice bath at 0°C to 10°C. The reaction was carried out by gas chromatography (GC).
2. The reaction mixture was kept stirred at 0 °C until the content of 1-tert-butylpyrazole was below 30% as shown by gas chromatography (GC) analysis.
3. the reaction mixture was gradually warmed to room temperature with continued stirring until the GC analysis showed that the content of 1-tert-butylpyrazole was less than 1.0%.
4. Upon completion of the reaction, 10% aqueous sodium bisulfite was added to the reaction mixture until it no longer showed blue color when detected using KI-starch test paper.
5. The organic phase was washed sequentially with 5% sodium chloride solution and saturated brine.
6. Evaporate the organic phase under pressure to obtain 4-bromo-1-tert-butyl-1H-pyrazole as a brown liquid (2.67 kg, yield 93.4%; GC purity 99.1%). | | References | [1] Patent: WO2011/134971, 2011, A1. Location in patent: Page/Page column 16; 17; 72
[2] Patent: WO2008/33999, 2008, A2. Location in patent: Page/Page column 84
[3] Patent: WO2014/1377, 2014, A1. Location in patent: Page/Page column 104
[4] Patent: US2013/40984, 2013, A1. Location in patent: Paragraph 0393-0395
[5] Patent: WO2017/42100, 2017, A1. Location in patent: Page/Page column 43 |
| | 4-bromo-1-tert-butyl-1H-pyrazole Preparation Products And Raw materials |
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