In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 1125828-26-3 as follows. Recommanded Product: 1-(2-Bromo-5-chlorophenyl)-3-methyl-1H-pyrazole
The above THF solution was transferred to a jacketed 3L 3-neck round bottom flask equipped with a mechanical stirrer, a temperature controller, and a nitrogen inlet. After diluting with THF (800 mL), the water content in the solution was checked by KF (0.053%). To the above solution was added a solution of i-PrMgCl in THF (Aldrich 2 M, 286 mL, 0.572 mol) at 0-10 C. over 1 hours. The resulting solution was stirred for 30 minutes at 10 C. (GC showed the completion of magnesium-bromine exchange reaction). Ethyl trifluoroacetate (74 mL, 0.620 mol) was then added to the Grignard solution between -20 and -10 C. over 45 minutes, slowly warmed to 0 C., and stirred for 30 minutes at the same temperature. The reaction mixture was poured into 2 N HCl (300 mL) at 0 C., and stirred for 30 minutes at room temperature. The organic layer was diluted with MTBE (500 mL), and washed with brine (250 mL) followed by water (250 mL). Solution assay of organic layer was carried out using GC (Compound 5: 67% solution yield, the corresponding regioisomer 6 was present at about 20% relative to 5). The solution was then concentrated under vacuum to 2× solution. To remove water, THF (500 mL) was added, and evaporated to 2× solution. THF addition-concentration was repeated to give a 2× solution. Heptane (500 mL) was added, concentrated to 2× solution to exchange the solvent for recrystallization. Heptane (500 mL) was again added, concentrated to 3.5× solution.The 3.5× heptane solution was then transferred to a 1L 3-neck jacketed round bottom flask equipped with a mechanical stirrer, a temperature controller, and a nitrogen inlet. The solution was heated at 60 C., and the resulting homogeneous solution was slowly (1-2 h) cooled to room temperature with stirring, further cooled to 0 C. and stirred for 30 minutes at the same temperature. The crystals were collected and washed with ice-cold heptane (200 mL), dried under vacuum at 50 C. to afford a pale yellow solid (Compound 5, 85.7 g, 99% pure by GC, 62% yield from fluoride 1). M.p.: 83 C. (DSC onset temperature) 1H NMR (400 MHz, CDCl3) delta 7.85 (1H, d, J=2.5 Hz), 7.48 (1H, d, J=1.7 Hz), 7.38 (1H, d, J=8.3 Hz), 7.31 (1H, dd, J=8.1, 1.8 Hz), 6.33 (1H, d, J=2.5 Hz), 2.30 (3H, s); 13C NMR (100 MHz, CDCl3) delta 184.2 (q, JC-F=36.6 Hz), 151.7, 138.7, 138.5, 130.7, 126.4, 125.7, 124.5, 116.8, 116.1 (q, JC-F=289.8 Hz), 109.7, 13.0; 19F NMR (376 MHz, CDCl3) delta=-76.8 (s).
According to the analysis of related databases, 1125828-26-3, the application of this compound in the production field has become more and more popular.
Reference:
Patent; Bednarz, Mark S.; Burgoon, JR., Hugh Alfred; Iimura, Shinya; Kanamarlapudi, Ramanaiah C.; Song, Qiuling; Wu, Wenxue; Yan, Jie; Zhang, Haiming; US2009/62540; (2009); A1;,
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