Reference of 5334-39-4, These common heterocyclic compound, 5334-39-4, name is 3-Methyl-4-nitro-1H-pyrazole, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
To a solution of 3 -methyl ~4-nitro- lH-pyrazole ( 10 g, 78,68 mmol) in DMF (50 mL) was added portionwise NaH (4.72 g, 1 18 ,02 mmol, 60% purity) at 0 C over 30 min. After addition, the mixture was stirred at 20 C for 30 min, and then 3- bromo-3-methylbutan-2-one ( 15.58 g, 94.42 mmol) was added dropwise at 0 C. The resulting mixture was stirred at 20 C for 1 1 h. The reaction mixture was quenched by addition of H20 (250 mL) at 0C, and extracted with EtOAc (3 chi 100 mL). The combined organic layers were washed with brine (50 mL), dried over Na2SO/j, filtered and concentrated under reduced pressure to give a residue. The residue was purified by column chromatography on silica gel (PE/EtOAc = 20/1 to 3/1). 3-methyl-3-(3-methyi-4- nitro-lH-pyrazol-l-yl)butan-2-one was obtained as a yellow solid. LCMS: RT 0.674 min, m/z = 212 [M + H]+. ‘H NMR (400 MHz, CDC13): 6 ppm 8.30 (s, 1 H) 2.56 (s, 3 H) 1.98 (s, 3 H) 1.75 (s, 6 H)
The synthetic route of 5334-39-4 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; DENALI THERAPEUTICS INC.; ESTRADA, Anthony A.; FENG, Jianwen A.; LYSSIKATOS, Joseph P.; SWEENEY, Zachary K.; DE VICENTE FIDALGO, Javier; (271 pag.)WO2017/87905; (2017); A1;,
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