Related Products of 1202993-11-0, 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. 1202993-11-0, name is 5-Chloro-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid belongs to pyrazoles-derivatives compound, it is a common compound, a new synthetic route is introduced below.
5-Chloro-3-(difluoromethyl)- 1-methyl-i H-pyrazole-4-carboxylic acid (700 mg, 2.38 mmol) was dissolved in abs. dichioromethane (20 ml) in a baked-out round- bottom flask under argon and at room temperature, and oxalyl chloride (257 mg, 2.02 mmol) and catalytic amounts of N,N-dimethylformamide were added. The resulting reaction solution was then stirred under reflux conditions for 3 h. Afier cooling to room temperature, the reaction mixture was concentrated and coevaporated with a little abs. toluene.By thorough removal of solvent residues, 5-chloro-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carbonyl chloride (743 mg, 2.38 mmol) was obtained, which was then, without further purification, dissolved again in abs. dichloromethane (10 ml) and added dropwise to a solution, cooled to 0 C., of N,N-dimethylhydrazine (0.18 ml, 2.38 mmol) and triethylamine (0.40 ml, 2.85 mmol) in dichloromethane (10 ml) under argon. The resulting reaction mixture was stirred at room temperature for a further 30 minutes, and then water and dichloromethane were added. The aqueous phase was repeatedly extracted vigorously with dichloromethane, and the combined organic phases were then dried over magnesium sulfate, filtered and concentrated. Final purification of the resulting crude product by column chromatography gave 5-chloro-3-(difluoromethyl) -N’,N’,1-trimethyl-1H-pyrazole-4-carbohydrazide in the form of a colorless solid (541 mg, 90% of theory). 5-Chloro-3-(difluoromethyl) -N?,N?,1 -trimethyl- iH-pyrazole-4-carbohydrazide (212 mg, 0.84 mmol) was dissolved in abs. tetrahydrofuran (5 ml) under argon, and sodium hydride (37 mg, 0.92 mmol, 60% purity) was added at room temperature. Stirring at room temperature for 30 minutes was followed by the addition of picolyl chloride (107 mg, 0.84 mmol), and the resulting reaction mixture was stirred under reflux conditions for 2 hours. After cooling to room temperature, sat. sodium hydrogencarbonate solution, water and dichioromethane were added. The aqueous phase was repeatedly extracted vigorously with dichioromethane, and the combined organic phases were then dried over magnesium sulfate, filtered and concentrated. Final purification of the resulting crude product by colunm chromatography gave 5-chloro-3-(difluoromethyl)-N?,N?, 1 -trimethyl-N-(pyridin-2-ylmethyl)- iH-pyrazole4-carbohydrazide in the form of a colorless solid (196 mg, 68% of theory). ?H-NMR (400 MHz, CDC13 oe, ppm) 8.64 (m, iH), 7.73 (m, iH), 7.63 (m, iH), 7.36 (m, iH), 7.15-6.88 (br. t, iH, CHF2), 5.11 (s, 2H), 3.86 (s, 3H), 3.48 (s, 6H).
In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 5-Chloro-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid, other downstream synthetic routes, hurry up and to see.
Reference:
Patent; Bayer CropScience Aktiengesellschaft; FRACKENPOHL, Jens; BOJACK, Guido; BRUENJES, Marco; HELMKE, Hendrik; LEHR, Stefan; BRUECHNER, Peter; TIEBES, Joerg; MOSRIN, Marc; DITTGEN, Jan; SCHMUTZLER, Dirk; DESBORDES, Philippe; (92 pag.)US2018/206498; (2018); A1;,
Pyrazole – Wikipedia,
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