Triethylamine → 4-bromo-N-(4-bromo-2-fluorobenzyl)-2-nitrobenzamide

To a solution of 4-bromo-2-fluorobenzylamine (2.3 g) and triethylamine (1.55 ml) in chloroform (40 ml) was added dropwise a solution of 4-bromo-2-nitrobenzoyl chloride (2.69 g) in chloroform (10 ml) at 0° C. with stirring and the mixture was stirred at the same temperature for 1 hour. The reaction mixture was washed in turn with diluted aqueous hydrochloric acid and water, and then dried. Evaporation of the solvent followed by recrystallization from diethyl ether gave 4-bromo-N-(4-bromo-2-fluorobenzyl)-2-nitrobenzamide (3.60 g).