2075-45-8

540-51-2

214614-81-0

General procedure for the synthesis of 1-(2-hydroxyethyl)-4-bromopyrazole from 4-bromopyrazole and 2-bromoethanol: 4-bromopyrazole (400 mg, 2.72 mmol), potassium iodide (671 mg, 4.04 mmol), potassium hydroxide (290 mg, 5.2 mmol), and 2-bromoethanol (625 mg, 5.0 mmol) were reacted in an ethanol (10 mL) The mixture in a microwave reactor was placed in a microwave reactor and reacted at 155 °C for 8 hours. Upon completion of the reaction, the reaction mixture was cooled to room temperature, filtered to remove insoluble material, followed by rotary evaporation to remove the solvent. The residue was dissolved in 20 mL of ethyl acetate, washed with 20 mL of water, dried over anhydrous sodium sulfate, and concentrated to give 1-(2-hydroxyethyl)-4-bromopyrazole (0.45 g, 86% yield) as a yellow oil.