Hydrogen Bromide → 2-bromo-1-(1-methyl-1H-pyrazol-4-yl)ethan-1-one

Participants

Reaction Steps

To a solution of 1-(1-methyl-1H-pyrazol-4-yl)ethanone (0.602 g, 4.85 mmol) in chloroform (20 mL) and of 33% HBr in acetic acid (3.92 mg, 0.05 mmol) was added dropwise a chloroform solution containing Br2 (0.262 mL, 5.09 mmol) via an addition funnel. The reaction mixture was stirred at room temperature for 1 h and then concentrated under reduced pressure. The crude solid was triturated in ethyl acetate, filtered, washed and dried in vacuo. The free base was obtained by triturating the product in 5% NaHCO3 for 2 h. The solid that formed were collected by filtration, washed with water and isopropyl alcohol and then dried in vacuo. Isolation gave 874 mg of the title compound.

Provenance & Evidence