Ethyl 4-bromopyrazolyl acetate can be used as a pharmaceutical synthesis intermediate, and can be used in laboratory research and development processes as well as in chemical and pharmaceutical synthesis processes.
Preparation of 4-bromopyrazolyl ethyl acetate: 4-bromo-1H-pyrazole (1.00 g, 6.80 mmol) was dissolved in 10 mL of DMF, placed in an ice bath, and then added in batches with a mass fraction of 60% sodium hydride (326.56 mg, 19.69 mmol). After addition, stirring for 1h, add ethyl bromoacetate (0.83mL, 7.48mmol), KI (225.90mg, 1.36mmol), raise the temperature to 80C, the reaction was 8h, cooled to room temperature, 20mL H2O was added to the reaction solution, the EA was extracted (275mL), and the organic layers were combined, and then the organic layers were extracted sequentially with H2O (315mL), saturated NaCl solution 40mL washing, anhydrous Na2SO4 drying, filtration, evaporation of solvent under reduced pressure, by rapid separation column chromatography (petroleum ether / ethyl acetate 10/1, v / v) separated and purified to obtain a transparent liquid 4-bromopyrazolyl ethyl acetate 1.327g, yield 83.46%.
