N-bromobutanimide → (2RS)-1,1,1-trifluoro-2-(4-ethoxyphenyl)-3-[(RS)-alpha-bromo-3-phenoxybenzyloxy]-propane

A catalytic amount of α,α'-azo-iso-butyronitrile was added to a solution of N-bromosuccinimide (0.14 g) and (RS)-1,1,1-trifluoro-2-(4-ethoxyphenyl)-3-(3-phenoxybenzyloxy)propane (0.3 g) in carbon tetrachloride (14 cm3). The reaction mixture was heated at the reflux temperature for 90 minutes, then cooled to 0° C., filtered, and the filtrate concentrated by evaporation under reduced pressure to leave (2RS)-1,1,1-trifluoro-2-(4-ethoxyphenyl)-3-[(RS)-α-bromo-3-phenoxybenzyloxy]-propane as a pale yellow oil which was used without further purification.