Trifluoroacetic acid → (E)-N-(2-Aminoethyl)-2-bromo-4-(4,4,4-trifluoro-3-(3,4,5-trichlorophenyl)but-1-enyl)benzamide

TFA (0.5 mL) was added to a stirred solution of (E)-tert-butyl 2-(2-bromo-4-(4,4,4-trifluoro-3-(3,4,5-trichlorophenyl)but-1-enyl)benzamido)ethylcarbamate (200 mg, 0.31 mmol) in CH2Cl2 (10 mL) at 0° C. and the reaction mixture was then stirred at ambient temperature for 18 h. The volatiles were evaporated under reduced pressure; water was added to the residue and the mixture was extracted with CH2Cl2. The organic layer was washed with brine, dried (Na2SO4), filtered, concentrated and the residue was purified by column chromatography on silica (100-200 mesh) eluting with 1-5% MeOH in CH2Cl2 to afford the title compound as a brown solid (50 mg, 31%): 1H NMR (400 MHz, DMSO-d6) δ 8.56 (bs, 1H), 7.70 (bs, 2H), 7.94-7.91 (m, 3H), 7.62-7.59 (m, 1H), 7.50 (d, J=7.6 Hz, 1H), 7.00 (dd, J=15.6, 9.2 Hz, 1H), 6.77 (d, J=15.6 Hz, 1H), 4.84-4.81 (m, 1H), 3.46-3.41 (m, 2H), 2.95-2.92 (m, 2H); ESIMS m/z 528.72 ([M+H]+); IR (thin film) 3435, 1671, 1113, 722, 555 cm−1.