A mixture of ethyl 1-(4-amino-3-bromo-5-(cyclopropylmethoxy)phenyl)cyclopentanecarboxylate (5.1 g, 14 mmol), 4-trifluoromethylphenylboronic acid (3.36 g, 17 mmol), CsF (0.28 g, 1.84 mmol) and Pd (PPh3)4 (0.410 g, 0.4 mmol) in 75 mL anhydrous 1,2-dimethoxy ethane was refluxed for 8 h under argon. The reaction mixture was cooled, and 75 mL of EtOAc and 75 mL of water were added. The organic phase was separated, dried over Na2SO4, filtered and concentrated under reduced pressure to yellow oil. The oil was purified by chromatography over silica gel (hexane/EtOAc) to give ethyl 1-(6-amino-5-(cyclopropylmethoxy)-4′-(trifluoromethyl)biphenyl-3-yl)cyclopentanecarboxylate (4.6 g) as a yellow oil.
