Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 13808-64-5, name is 4-Bromo-3-methylpyrazole, A new synthetic method of this compound is introduced below., category: pyrazoles-derivatives
10330] To a suspension of NaH 60% in oil (0.3 g; 7.45 mmol) in tetrahydrofuran (150 mE) there is added, at 100 C., 4-bromo-3-methyl-1H-pyrazole dissolved in 15 mE of tetrahydrofuran dropwise, over 15 minutes. Afier stirring for 40 minutes at ambient temperature, iodomethane (0.45 mE; 7.45 mmol) is added dropwise, and then the reaction mixture is stirred overnight. Afier adding water, the reaction mixture is evaporated and taken up in dichloromethane. The organic phase is separated off and dried over Mg504, filtered and concentrated to dryness. The residue is purified by chromatography over silica gel to yield a mixture of the title compounds (4-bromo-1 ,3-dimethyl-pyrazole and 4-bromo-1 ,5- dimethyl-pyrazole respectively in a ratio of 4:6).4-bromo-1 ,5-dimethyl-1H-pyrazole10331] ?H NMR (500 MHz, dmso-d6) oe ppm: 7.41 (s, 1H),3.76 (s, 3H), 2.22 (s, 3H)4-bromo-1 ,3-dimethyl-1H-pyrazole10332] ?H NMR (500 MHz, dmso-d6) oe ppm: 7.81 (s, 1H),3.74 (s, 3H), 2.09 (s, 3H)
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; LE TIRAN, Arnaud; LE DIGUARHER, Thierry; STARCK, Jerome-Benoit; HENLIN, Jean-Michel; GUILLOUZIC, Anne-Francoise; DE NANTEUIL, Guillaume; GENESTE, Olivier; FEJES, Imre; TATAI, Janos; NYERGES, Miklos; DAVIDSON, James Edward Paul; MURRAY, James Brooke; CHEN, I-Jen; DURAND, Didier; US2015/31673; (2015); A1;,
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