Allyl bromide → 1-(Prop-2-en-1-yl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-pyrazoleboronic acid pinacol ester (3.0 g, 15.6 mmol), allyl bromide (6.9 g, 77 mmol) and sodium bis(trimethylsilyl)amide (20.5 mL of a 1.5N solution in THF, 30.7 mmol) in THF (20 mL) was heated to 70° C. overnight. After cooling to r.t. the reaction was quenched with water (15 mL) and extracted with EtOAc (2×30 mL). The combined organic fractions were washed with brine (50 mL), dried (MgSO4) and concentrated in vacuo to give the title compound (3.4 g, 94%) as a yellow oil. δH (CDCl3) 1.20 (12H, s), 4.61-4.67 (2H, m), 5.06-5.24 (2H, m), 5.79-6.01 (1H, m), 7.60 (1H, s), 7.69 (1H, s).

Provenance & Evidence