Potassium Cyanide → 2-Bromo-4-chloro-6-fluorobenzonitrile

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-bromo-4-chloro-6-fluoro-phenylamine (10 g, 44.5 mmol) in anhydrous CH2Cl2 (100 ml) was added nitrosonium tetrafluoroborate (5.72 g, 49.01 mmol) and the mixture was stirred at 25° C. for 1 h. The reaction mixture was then cooled to 0° C. prior to addition of KCN (5.8 g, 89.1 mmol) followed by a dropwise addition of an aqueous solution (50 ml) of cupric sulfate hexahydrate (22.24 g, 89.1 mmol). After stirring for 40 minutes at 0° C., the reaction mixture was allowed to warm to 25° C. and stirring was continued for 1 h. The reaction mixture was diluted with CH2Cl2 (100 ml) and slowly quenched by the addition of aqueous saturated solution of NaHCO3 until gas evolution was no longer observed. The resulting heterogeneous mixture was then filtered through a pad of celite and the organic layer was separated, washed twice with brine, dried with Na2SO4 and evaporated. The crude residue thus obtained was purified by chromatography (silica gel; hexane/EtOAc 90:10) to obtain the title compound (4 g, 38%) as reddish solid.

Provenance & Evidence