Synthetic Route of 138786-86-4,Some common heterocyclic compound, 138786-86-4, name is Methyl 4-nitro-1H-pyrazole-3-carboxylate, molecular formula is C5H5N3O4, 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 4-nitro-lH-pyrazole-3-carboxylic acid methyl ester (3.1 g, 18.1 mmol) in dry acetone (2 ml) was added K2C03 (5 g, 36.2 mmol) at 25C. The reaction mixture was cooled to 0C, and methyl iodide (2.2 ml, 36.3 mmol) was added. The temperature was again raised to 25C, and then heated to 70C for 2 hrs. The solvent was removed in vacuo The residue was diluted with EtOA and washed with water and with brine, dried (Na2S04), filtered, and concentrated. The crude product was purified by column chromatography over silica gel. Elution with 20% EtOAc/hexane) gave the undesired isomer 2-methyl-4-nitro-2H-pyrazole-3-carboxylic acid methyl ester (1 g, 30%), subsequent elution with 40% EtOAc/hexane provided the desired isomer l-methyl-4-nitro-lH-pyrazole-3-carboxylic acid methyl ester (1.8 g, 54%).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 4-nitro-1H-pyrazole-3-carboxylate, its application will become more common.
Reference:
Patent; F. HOFFMANN-LA ROCHE AG; BLEICHER, Konrad; FLOHR, Alexander; GROEBKE ZBINDEN, Katrin; GRUBER, Felix; KOERNER, Matthias; KUHN, Bernd; PETERS, Jens-Uwe; RODRIGUEZ SARMIENTO, Rosa Maria; WO2011/154327; (2011); A1;,
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