N-Bromosuccinimide (9.70 g, 54.5 mmol) and benzoyl peroxide (0.7 g) were added to a solution of tert-butyl 2-[(tert-butoxycarbonyl)oxy]-6-methyl-3-(trifluoromethyl)benzoate (18.6 g, 49.6 mmol) obtained in Example (28-4) in carbon tetrachloride (400 ml), and the mixture was heated under reflux for 5 hours. The temperature of the reaction mixture was returned to room temperature and the solvent was removed under reduced pressure. After n-hexane was added to the obtained residue and the mixture was filtered, the filtrate was concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (eluting solvent: toluene) to give tert-butyl 6-(bromomethyl)-2-[(tert-butoxycarbonyl)oxy]-3-(trifluoromethyl)benzoate (11.66 g, yield: 52%).
