General procedure for the synthesis of 5-amino-2-bromobenzotrifluoride from 2-bromo-5-nitrobenzotrifluoride: 300 mL of methanol, 284 g of 2-bromo-5-nitrobenzotrifluoride, 20 g of Raney Ni Catalyst, and 1.0 g of piperazine were added to a 1 L high pressure hydrogenation reactor. The air in the reactor was replaced with hydrogen 3-4 times, followed by the hydrogenation reaction at a hydrogen pressure of 0.8-1.0 MPa and 80-90 °C until no more hydrogen was consumed. Upon completion of the reaction, the reaction mixture was cooled and filtered to remove the Raney Ni catalyst. Methanol and water were removed by distillation under reduced pressure, and the final product was obtained by simple distillation as a pale yellow liquid product, 5-amino-2-bromobenzotrifluoride, 250 g, with a GC purity of 95% and a yield of 98.8%.The Raney Ni catalyst and the solvent, methanol, can be recovered for reuse.
