1-(2-Methoxyethyl)-1H-Pyrazole-5-Carboxylic Acid synthesis

Yield:936249-31-9 81%

Reaction Conditions:

with water;sodium hydroxide in ethanol at 20; for 1.5 h;

Steps:

2 1^{-(2-Methoxyethyl)-1H-pyrazole-5-carboxylic acid}

T^{o a solution of Ethyl 1-(2-methoxyethyl)-1H-pyrazole-5-carboxylate (150 mg, 0.76 mmol) in ethanol was added a solution of NaOH (1.1 equiv., 0.84 mmol) in water (1 mL). The resulting mixture was stirred at room temperature for 1.5 h. Ethanol was removed under vacuum, the residue was acidified with a solution of 1M HCl, and the resulting aqueous solution was extracted} w_{ith DCM. The organic solution was dried over Na2SO4 and evaporated under reduced pressure to give 1-(2-Methoxyethyl)-1H-pyrazole-5-carboxylic acid (105 mg, 81%) as a white solid. UPLC-MS (Acidic Method, 2 min): rt 0.54 min, m/z 171.1 [M+H]+} 1_{H NMR (400 MHz, CDCl3) d ppm: 7.56-7.58 (m, 1H), 6.95-6.97 (m, 1H), 4.76-4.81 (m, 2H), 3.79- 3.83 (m, 2H), 3.34-3.36 (m, 3H), 0.08 (s, 1H)}

References:

WO2020/43880,2020,A1 Location in patent:Page/Page column 16; 17