|
|
| | 4-bromo-1-methylpyrazole-3-carboxy acid Basic information |
| Product Name: | 4-bromo-1-methylpyrazole-3-carboxy acid | | Synonyms: | 1-Methyl-4-bromopyrazole-5-carboxylic acid;4-bromo-1-methylpyrazole-3-carboxy acid;4-bromo-1-methyl-1H-pyrazole-5-carboxylic acid(SALTDATA: FREE);4-Bromo-2-methylpyrazole-3-carboxylic acid;4-bromo-2-methyl-3-pyrazolecarboxylic acid;1H-Pyrazole-5-carboxylic acid, 4-bromo-1-methyl-;4-Bromo-1-methylpyrazole-5-carboxylic Acid | | CAS: | 84547-84-2 | | MF: | C5H5BrN2O2 | | MW: | 205.01 | | EINECS: | | | Product Categories: | | | Mol File: | 84547-84-2.mol |  |
| | 4-bromo-1-methylpyrazole-3-carboxy acid Chemical Properties |
| Melting point | 235-236 °C | | Boiling point | 347.4±27.0 °C(Predicted) | | density | 1.93±0.1 g/cm3(Predicted) | | storage temp. | 2-8°C | | pka | 1.75±0.37(Predicted) | | Appearance | White to off-white Solid |
| | 4-bromo-1-methylpyrazole-3-carboxy acid Usage And Synthesis |
| Synthesis | 1. 600 ml of anhydrous THF was added to a 2L reaction flask under argon protection.
2. 65.4 g of diisopropylamine was added and the reaction system was subsequently cooled to -78 °C via a dry ice acetone bath.
3. 258 ml of 2.5 M n-butyllithium solution was slowly added dropwise at 0 °C. After the dropwise addition, the reaction temperature was raised to 0 °C and maintained for 0.5 h. The reaction system was then cooled to -78 °C again.
4. 80.0 g of 1-methyl-4-bromopyrazole was slowly added dropwise at -78 °C, and after the dropwise addition was completed, the reaction temperature was maintained at -78 °C for 1 hour.
5. dry carbon dioxide gas was passed into the reaction system until TLC detection showed that the reaction was complete.
6. The pH of the reaction solution was slowly adjusted to 2-3 with 1N HCl, at which time a large amount of white solid was precipitated.
7. The reaction mixture was cooled at 0 °C for 3 h, followed by filtration to collect the white solid.
8. The resulting solid was dried at 40 °C for 16 h to give 77.3 g of white solid compound 22 (4-bromo-1-methyl-1H-pyrazole-5-carboxylic acid). | | References | [1] Patent: CN108264520, 2018, A. Location in patent: Paragraph 0261; 0262; 0263; 0264; 0265 |
| | 4-bromo-1-methylpyrazole-3-carboxy acid Preparation Products And Raw materials |
|