A common compound: 5334-40-7, name is 4-Nitro-1H-pyrazole-3-carboxylic acid, belongs to pyrazoles-derivatives compound, it can change the direction of chemical reaction, and react with certain compounds to generate new functional products. A new synthetic method of this compound is introduced below. 5334-40-7
2-(methylamino)ethanol (2.00 g, 26.63 mmol) and 4-nitro-1H-pyrazole-3-carboxylic acid (3.54 g, 22.52 mmol) in toluene (24.44 mL) were stirred at 15 ¡ãC. SOd2 (4.52 mL, 62.28 mmol) was slowly added followed by DMF (171.44 jiL, 2.21 mmol). The reaction mixturewas stirred at 55 ¡ãC for 10 minutes then 70 ¡ãC for 18 h. Solvents were evaporated. The residue was taken up into DMF (20.62 mL) and TEA (16.66 mL) was added slowly. The reaction mixture was stirred at rt for 12 h. Water was added and the mixture was extracted twice with EtOAc, dried over Mg504, filtered and evaporated. The crude residue was purified via silica gel chromatography (Stationary phase: irregular SiOH 15-40 jim, 80 g,mobile phase gradient: from 100percent DCM to 97percent DCM, 3percent MeOH (+ 10percent NH4OH)) to give 1.96 g of intermediate 14b (38percent yield).
In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 5334-40-7, other downstream synthetic routes, hurry up and to see.