Related Products of 26621-44-3, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 26621-44-3 name is 3-Nitro-1H-pyrazole, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
[313] To a 0 C solution of 3-nitro-1H-pyrazole (250.0 g, 2.17 mol, 1.0 eq) in anhydrous DMF (2.5 L; 10.2 vol eq) under nitrogen was added NaH (95.42 g of 60 %w/w, 2.39 mol, 1.1 eq) in batches over 30 min while maintaining temperature below 8 C. The mixture was stirred for 1 h then 2,4-difluoropyridine (300 mL, 3.29 mol, 1.5 eq) was added, and the reaction was warmed to room temperature and stirred for approximately 16 hours (h). The reaction mixture was diluted with water (12.5 L) and stirred vigorously for 1 h. The off-white solid was collected by vacuum filtration. The solid was re-suspended in water (2 L) and filtered, and this step was repeated once further. The product was dried under vacuum, then suspended in heptane (4L), stirred 3 h at room temperature, and filtered. The solid was washed with two further portions of heptane (2 L each) and dried under vacuum to provide 2-fluoro- 4-(3-nitro-1H-pyrazol-1-yl)pyridine (426.3 g of 92% purity, 87% yield). 1H NMR (400 MHz, DMSO-d6) delta 9.01 (d, J = 2.8 Hz, 1H), 8.45 (d, J = 5.7 Hz, 1H), 7.95 (ddd, J = 5.7, 1.9, 1.2 Hz, 1H), 7.81 (t, J = 1.4 Hz, 1H), 7.46 (d, J = 2.8 Hz, 1H) ppm. ESI-MS m/z calc. 208.04, found 209.01 (M+1).
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-Nitro-1H-pyrazole, and friends who are interested can also refer to it.
Reference:
Patent; VERTEX PHARMACEUTICALS INCORPORATED; CHARIFSON, Paul, S.; COME, Joh, H.; COURT, John, J.; GALE-DAY, Zachary; GU, Wenxin; JACKSON, Katrina, L.; MAGAVI, Sanjay, Shivayogi; NANTHAKUMAR, Suganthini, S.; RONKIN, Steven, Michael; SWETT, Rebecca, Jane; TANG, Qing; (383 pag.)WO2018/107056; (2018); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics