Hydrogen Bromide → 5-Bromo-1-chloro-2,3-difluorobenzene

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-chloro-4,5-difluoroaniline (2.1 g, 12.96 mmol) in hydrobromic acid (40% in H2O, 18.7 mL) was added dropwise a solution of sodium nitrite (0.96 g, 13.6 mol) in 7.5 mL H2O at 0° C. Then the mixture was poured into a solution of copper(I) bromide (3.5 g, 23.7 mmol) in hydrobromic acid (40% in H2O, 15 mL) at 0° C. The cooling bath was then removed and the mixture was heated at 60° C. overnight. After cooling, the mixture was basified with a solution 2N NaOH solution to pH=9 and diluted with CH2Cl2. After separation, the combined organic layers were washed with brine, dried over Na2SO4 and then concentrated to get crude product, which was purified by column with PE/EtOAc (from 100:1 to 20:1) as eluant to afford 2 g product. Yield 68.3%; 1H NMR (400 MHz, CDCl3): δ 7.37-7.35 (m, 1 H), 7.30-7.25 (m, 1 H) ppm.

Provenance & Evidence