Hydrogen Bromide → 2-Bromo-1-(4-fluorophenyl)-2-(4-(methylsulfonyl)phenyl)ethanone

Participants

Reaction Steps

To a stirred slurry of 1-(4-fluorophenyl)-2-(4-methylsulfonylphenyl) ethanone from Step 1 (3.03 g, 10.38 mmol) in acetic acid (40 mL) was added HBr in acetic acid (2 mL, 48% by wt. ) and bromine (0.64 mL, 1.99 g, 12.45 mmol). Within minutes the slurry became homogeneous. After 1 hour, the reaction was concentrated in vacuo, diluted with methylene chloride and reconcentrated in vacuo yielding 2-bromo-1-(4-fluorophenyl)-2-(4-methylsulfonylphenyl) ethanone as a tan solid (3.53 g, 95%) which could be used without further purification. mp 140°-141° C., 1H NMR (CDCl3) 300 mHz δ8.05 (dd, J=5.16, 8.84 Hz, 2H), 7.96 (d, J=8.48 Hz, 2H), 7.75 (d, J=8.48 Hz, 2H), 7.17 (t, J=8.48 Hz, 2H), 6.29 (s, 1H), 3.06 (s, 3H). MS: m/e 371/373 (MH+). HRMS Δ=5.5 mmu.

Provenance & Evidence