At room temperature, 100 mmol of o-aminobenzonitrile, 200 mmol of p-bromophenylboronic acid, 5 mmol of nickel catalyst Ni(dppe)Cl2 and 400 mmol of trifluoroacetic acid were added to an appropriate amount of mixed solvent (a mixture of 1,4-dioxane and water in a volume ratio of 4:1) in a reaction vessel. The mixture was then stirred and heated to 90 °C, and the reaction was carried out at this temperature for 24 hours.
After the reaction was complete, the reaction mixture was first rotary evaporated to dryness. Then, sufficient ethyl acetate was added to dissolve it. Next, a suitable amount of a mixed aqueous solution of saturated sodium bicarbonate and saturated sodium chloride was added for washing. The organic and aqueous layers were separated. The aqueous layer was extracted three times with ethyl acetate. The organic layers (i.e., the organic layer washed with the mixed aqueous solution and the organic layer obtained from the ethyl acetate extraction) were combined, dried over anhydrous sodium sulfate, and distilled under reduced pressure. The residue was eluted by rapid column chromatography (using a mixture of petroleum ether and ethyl acetate in a volume ratio of 1:0.5 as the eluent). The eluent was collected and evaporated to remove the eluent, yielding 2-amino-4'-bromo-benzophenone as a pale yellow solid with a yield of 86.8% and a purity of 94.6%.
