To a solution of tert-butyl (1-(4-acetylphenyl)cyclobutyl)carbamate (0.1 g, 1 eq.) in chloroform (3.5 mL) and methanol (1.5 mL) was added the tetrabutyl ammonium tribromide (0.175 g, 1.05 eq.). The mixture was stirred at 40° C. for 90 minutes. The reaction mixture was diluted with dichloromethane (10 mL), washed with water (10 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure. The product was purified by column chromatography (10% ethyl acetate in dichloromethane), giving tert-butyl (1-(4-(2-bromoacetyl)phenyl)cyclobutyl)carbamate (0.1 g, 78%) as a colorless oil. LCMS: 312 [M−tBu+H], 314 [M−tBu+H].
