In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 15803-02-8, name is 4-Bromo-1-methyl-1H-pyrazole belongs to pyrazoles-derivatives compound, it is a common compound, a new synthetic route is introduced below. HPLC of Formula: C4H5BrN2
A. Synthesis of 1-(1-methyl-1H-pyrazol-4-yl)ethanone 4-Bromo-1-methyl-1H-pyrazole (41.3 mL, 400 mmol), was dissolved in tetrahydrofuran (750 mL) and cooled to -78 C. N-Butyllithium (2.5 M solution in hexanes, 160 mL, 400 mmol) was added drop-wise over 30 minutes, and the resulting mixture was stirred for 1 hour at -78 C. After drop-wise addition of a solution of N-methoxy-N-methylacetamide (40.9 mL, 400 mmol) in tetrahydrofuran (100 mL) to the -78 C. reaction mixture, the cooling bath was allowed to warm to 0 C. over 4 hours. The reaction was then quenched with saturated aqueous sodium chloride solution (50 mL), and volatiles were removed in vacuo. The residue was diluted with ethyl acetate (1000 mL), treated with magnesium sulfate, and stirred for 30 minutes before being filtered and concentrated in vacuo. Purification was carried out via silica gel chromatography (material was loaded in a minimum amount of dichloromethane; Gradient: 5% to 100% ethyl acetate in heptane) to provide a pale yellow oil that solidified on standing. Yield: 28.5 g, 230 mmol, 57%. 1H NMR (500 MHz, CDCl3) delta 2.37 (s, 3H), 3.90 (s, 3H), 7.83 (s, 1H), 7.84 (s, 1H).
The synthetic route of 15803-02-8 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Pfizer Inc.; US2012/214791; (2012); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics