1,3-DIMETHYL-4-NITRO-1H-PYRAZOLE-5-CARBOXYLIC ACID ETHYL ESTER synthesis

Yield:78208-68-1 54 %

Reaction Conditions:

with sulfuric acid;nitric acid at 0 - 20;

Steps:

1.S1 Step 1: Preparation of ethyl 1,3-dimethyl-4-nitro-1H-pyrazole-5-carboxylate

Nitric acid (60%, 4 mL, 3.34 eq) and sulfuric acid (13 mL, 14.14 eq) were mixed at 0 °C.After stirring the mixture to room temperature, ethyl 1,3-dimethyl-1H-pyrazole-5-carboxylate (2.9 g, 1 eq) was added.The reaction mixture was then stirred at room temperature for 6 hours.As a result of LCMS analysis, all of the starting materials disappeared and the target compound was detected.The reaction mixture was poured into ice water, and the precipitated solid was filtered and dried to obtain the desired compound (2 g, 54% yield).

References:

WO2023/8885,2023,A1 Location in patent:Paragraph 86-90