Electric Literature of 34334-96-8, These common heterocyclic compound, 34334-96-8, name is 3-Methyl-5-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.
General procedure: The reaction was performed in 2 batches. In a sealed tube, cyanomethylenetributyl phosphorane (9.28 mL, 35.40 mmol) was added to a solution of 3-methyl-5-nitro-lH- pyrazole (1.50 g, 1 1.80 mmol) and 3-hydroxymethyl-3-methyloxethane (3.53 mL, 35.40 mmol) in toluene (100 mL). The solution was heated at 60 C for 18 h. The 2 batches were combined and the solvent was evaporated in vacuo. The residue (black oil) was purified by column chromatography on silica gel (irregular SiOH, 15-40 muiotaeta, 330 g, liquid loading on DCM, mobile phase: heptane/EtOAc, gradient from 90: 10 to 50:50). The fractions containing the product were combined and evaporated to dryness to give 3.95 g of intermediate 303 (79% yield, orange oil) directly used as it in the next step.
The synthetic route of 34334-96-8 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; JANSSEN PHARMACEUTICA NV; STANSFIELD, Ian; QUEROLLE, Olivier, Alexis, Georges; LIGNY, Yannick, Aime, Eddy; GROSS, Gerhard, Max; JACOBY, Edgar; MEERPOEL, Lieven; GREEN, Simon, Richard; HYND, George; KULAGOWSKI, Janusz, Jozef; MACLEOD, Calum; MANN, Samuel, Edward; (472 pag.)WO2018/2217; (2018); A1;,
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