Ethyl Bromide → 1-Ethyl-1H-pyrazole-4-boronic acid, pinacol ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (V-1) (3 g, 15 mmol) in DMF (6 mL) were added bromoethane (3.24 g, 30 mmol) and K2CO3 (4.26 g, 30 mmol). The reaction mixture was stirred at 60° C. overnight, then diluted with EtOAc, washed with water and then brine. The organic layer was separated, then dried over Na2SO4, and concentrated to afford the title compound (3.40 g). MS (m/z): 223 (M+1)+.

Provenance & Evidence