Hydrogen Bromide → 2-Bromo-1-chloro-4-(methylsulfonyl)benzene

Participants

Reaction Conditions

Reaction Steps

To a slurry of 2-chloro-5-methanesulfonyl-aniline (4.50 g, 21.9 mmol) in 48% HBr (12 mL) at 0° C. was added dropwise a solution of sodium nitrite (2.28 g, 33 mmol) in H2O (8 mL) at such a rate that the temperature never exceeds 5° C. The resulting yellow mixture was allowed to stir 20 min at 0° C. and then charged with copper(I) bromide (3.3 g, 23 mmol). After 30 min the resulting mixture was extracted with EtOAc (2×100 mL) and the combined extracts were washed successively with satd NH4Cl, 3N HCl and brine, then dried (Na2SO4) and concentrated under reduced pressure. The resulting residue was purified by chromatography (silica, EtOAc/Hex, 0:100 to 50:50) to give the title compound (4.92 g, 83%) as a white solid. GC-MS (EI): 268, 270.

Provenance & Evidence