Benzyl Bromide → 1-Benzyl-4-bromo-3-methyl-1H-pyrazole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a 500-mL 3-neck round-bottom flask, was placed a solution of 4-bromo-3-methyl-1H-pyrazole (20.0 g, 124 mmol) in N,N-dimethylformamide (100 mL). The system was purged with nitrogen, then the solution was cooled to 0° C. Sodium hydride (60% dispersion in mineral oil, 10.0 g, 250 mmol) was carefully added portion-wise and then the resulting mixture was stirred for 30 min at room temperature. The mixture was cooled to 0° C., then benzyl bromide (22.1 mL, 186 mmol) was added drop-wise and the resulting mixture was stirred overnight at room temperature. The mixture was carefully quenched by drop-wise addition of water (40 mL), then the mixture was extracted with ethyl acetate (3×200 mL). The combined organic extracts were washed with brine (4×100 mL), dried (Na2SO4), filleted and concentrated under reduced pressure to obtain the title compound as a yellow oil (24.9 g, 80%).

Herkunft & Nachweise